part 2: technical notes -...
TRANSCRIPT
PART 2: TECHNICAL NOTES
The technical notes are part two of four parts contained in this module. They provide an introduction to micronutrient malnu-trition. The technical notes are intended for people involved in nutrition programme planning and implementation. They providetechnical details, highlight challenging areas and provide clear guidance on accepted current practice. Words in italics areexplained in the glossary.
SummaryThis module provides an overview of micronutrient malnutrition and the methods used for its assessment. The commonmicronutrient deficiency diseases (MDD) are reviewed and their clinical signs are illustrated. Direct and indirect assessmentmethods for detecting micronutrient malnutrition are described and the continuing public health significance of micro-nutrient malnutrition is emphasised.
1HTP, Version 2, 2011
Micronutrient malnutritionMODULE 4
Key messages
1. Micronutrient malnutrition continues to affect populations in many parts of the world. It is often exacerbatedin emergencies and is a significant cause of morbidity, mortality, and reduced human capital.
2. The main cause of micronutrient malnutrition is usually an inadequate dietary intake of vitamins or minerals.
3. Food aid rations have often failed to meet Sphere standards for micronutrient adequacy. A low diversity dietwith the absence of micronutrient-fortified foods is a strong predictor of MDD.
4. Infections are an additional and important cause of micronutrient malnutrition and can negatively affectnutritional status by increasing nutrient requirements and reducing nutrient absorption.
5. Globally, iron deficiency anaemia is the most common micronutrient disorder. Large numbers are also affectedby iodine and vitamin A deficiencies. These endemic deficiencies often affect populations in emergencies.
6. In addition, epidemics of MDD such as pellagra, scurvy, beriberi, and ariboflavinosis occur in populations affectedby severe poverty or experiencing crisis.
7. Assessment of micronutrient deficiencies can be conducted using either direct or indirect approaches.
8. Appropriate ration planning and monitoring of food assistance programmes can greatly reduce the risk ofmicronutrient malnutrition. Software tools such as NutVal are available to assist in this task.
9. Ensuring that micronutrient deficiency diseases are monitored as part of the health information system isan important part of effective surveillance.
10. Major challenges exist in conducting investigations of MDD outbreaks. Specialist approaches may be requiredto accurately identify and quantify the extent of MDD.
TECHNICAL NOTES
2 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
Food Security and Nutrition Assessment Standard 2: NutritionWhere people are at increased risk of undernutrition, assessments are conducted using internationally accepted methodsto understand the type, degree and extent of undernutrition and identify those most affected, those most at risk, andthe appropriate response.
Food Security, Food Transfers Standard 1: General nutrition requirementsEnsure the nutritional needs of the disaster-affected population including those most at risk are met.
Key indicators
• There is adequate access to a range of foods, including a staple (cereal or tuber), pulses (or animal products)and fat sources, that together meet nutritional requirements
• There is adequate access to iodised salt for the majority (> 90%) of households
• There is adequate access to additional sources of niacin (e.g. pulses, nuts, dried fish) if the staple is maizeor sorghum
• There is adequate access to additional sources of thiamine (e.g. pulses, nuts, eggs) if the staple is polished rice
• There is adequate access to adequate sources of riboflavin where people are dependent on a very limited diet
• There are no cases of scurvy, pellagra, beriberi or riboflavin deficiency
• The prevalence of vitamin A deficiency, iron deficiency anaemia and iodine deficiency disorders are not of publichealth significance
Source: The Sphere Project (2011). Humanitarian Charter and Minimum Standards in Humanitarian Response. Geneva: The Sphere Project.
These technical notes are based on the technical references given in the resource list for the module and the Sphere standardsshown in the box below:
Sphere standard
1 WHO (2009) Global prevalence of vitamin A deficiency in populations at risk, 1995-2005 World Health Organisation: Geneva2 WHO (2004) Iodine Status Worldwide World Health Organisation: Geneva
IntroductionMicronutrient deficiencies are widespread in developingcountries with more than two billion people affected. For ex-ample, children continue to go blind due to vitamin A defi-ciency and about 33 per cent of preschool children in develop-ing countries have sub-clinical deficiency.1 Globally, about 16per cent of people in the general population are affected bygoitre, mainly due to insufficient consumption of iodine.2 Iodinedeficiency causes not only widespread endemic goitre but alsoretards growth and physical development; in its extreme form,this retarded growth is known as cretinism. Iron deficiency ana-emia – characterised by breathlessness and fatigue – is highlyprevalent worldwide with about 1.6 billion affected people.Unlike deficiencies in vitamin A and iodine, anaemia occurswidely in both industrialized and developing countries.
Micronutrient deficiencies occur more frequently in individualson a monotonous or restricted diet or in those with infections.Both these problems are characteristic of most emergency sit-
uations. Micronutrient deficiencies have been reported foryears in emergency settings and especially in refugee camps,where they have been most frequently assessed (see table 2).Some deficiency diseases, such as anaemia and vitamin Adeficiency, primarily affect children and women, while others,such as pellagra, are found more frequently in adult femalesand males. Micronutrient deficiencies have also been docu-mented in adolescents in African refugee camps.
Micronutrient deficiencies have many detrimental effects suchas an increase in morbidity (illness) and mortality (death) riskas well as impaired growth and mental development. Eradica-ting micronutrient deficiencies is a fundamental componentof any public health intervention.
This module covers the recognition and assessment of micro-nutrient malnutrition and micronutrient deficiency diseases.Approaches to treatment and prevention strategies for micro-nutrient deficiencies are covered in module 14.
TECHNICAL NOTES
3HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
Table 1: Definitions
Definitions Concepts
Micronutrient malnutrition: Micronutrient malnutrition can exist even when theThe existence of sub-optimal nutritional status due to a lack energy and macronutrient needs of an individual areof intake, absorption, or utilisation of one or more vitamins met. For that reason it is often referred to as ‘hiddenor minerals. Excessive intake of some micronutrients may hunger’. People may appear well fed but still bealso result in adverse effects. suffering from debilitating and life threatening
malnutrition.
Micronutrient deficiency disease (MDD): When certain micronutrients are severely deficientA clinical disease that arises due to a lack of intake, specific clinical signs and symptoms may develop.absorption, or utilisation of one or more vitamins The classic nutritional diseases such as scurvy,or minerals. beriberi and pellagra are good examples of these
sorts of disease.
Note: The term micronutrient deficiency disorder is also used when referring to micronutrient malnutrition and MDD.
Table 2: Examples of micronutrient deficiencies reported in emergency situations
Location Years
Vitamin C deficiency Somalia* 1982, 1985Sudan* 1984, 1991Ethiopia* 1989Kenya* 1994, 1996Afghanistan 2001, 2002
Vitamin A deficiency Sudan* 1985, 1987Kenya* 1998, 2001Nepal* 1999Ethiopia* 2001Uganda* 2001
Niacin deficiency Malawi* 1989, 1990, 1991, 1996Angola (internally displaced persons) 1999, 2000Angola 2002
Anaemia Kenya* 1998, 2001Nepal* 1999Uganda* 2001Ethiopia* 2001Algeria* 2002Thailand* 2001-2002Jordan* 1990Lebanon* 1990Syria* 1990Gaza* 1990West Bank* 1990
Thiamine deficiency Thailand* 1992Nepal* 1994-1995Kenya (internally displaced persons) 2000
Source: NICS (2007) Assessing micronutrient deficiencies in emergencies: Current practice and future directions Geneva: SCN
* In refugee camps
TECHNICAL NOTES
4 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
The main micronutrients and associateddeficiency diseasesMicronutrients include all vitamins and the minerals that areessential for human health. They are required in only small am-ounts but, nonetheless, are essential for life and needed for awide range of normal body functions and processes. Vitaminsare either water-soluble (e.g. the B vitamins and vitamin C) orfat-soluble (e.g. vitamins A, D, E and K). Essential mineralsinclude iron, iodine, zinc, calcium, and a large number of others.
Micronutrients are found in different amounts in differentfoods. Some micronutrients are widely available in a range offoods. Others, such as vitamin C, may be found only in certaintypes of food. A deficiency of a particular micronutrient is morecommon when it is only found in a limited range of foods andthese are not available to the whole population.
Micronutrients can be categorized as either Type 1 or Type 2nutrients.
Type 1 nutrient deficiencies result in specific deficiency dis-eases, do not always affect growth, but will affect metabolismand immune competence before signs are apparent. Thiscategory of nutrients includes vitamins A, B1, B2, B3, B6, B12,C, D, and folic acid, as well as iron, calcium, copper, iodine, andselenium.
Type 2 nutrient deficiencies do not show specific clinical signs.They affect metabolic processes and result in growth failure,wasting, increased risk of oedema, and lowered immune res-ponse. This category of nutrients includes sulphur, potassium,sodium, magnesium, zinc, phosphorus, water, essential aminoacids, and nitrogen deficiencies.
Table 3 lists nine of the most important micronutrients, theirfunctions, sources, and signs of deficiencies. Bear in mind thatthere are also other micronutrients (e.g. selenium and theothers listed above) that are extremely important for humannutrition, but these nine are considered to be of particularimportance in an emergency context.
The micronutrient requirements of an individual depend onage and sex. Nutrient requirements may also increase duringcritical period of rapid growth and development (pregnancy,lactation, infancy and early childhood) as well as during certainillnesses and diseases (such as malaria, diarrhoea, tuberculosis).
Annex 1 contains tables of vitamin and mineral requirementsrecommended by the World Health Organisation (WHO) andthe Food and Agricultural Organisation (FAO) for populations.
While we are usually concerned about people not receivingan adequate amount of micronutrients in their diet, it shouldnot be forgotten that there is a risk of toxicity with excessiveintakes of some micronutrients. For example, a high intake ofvitamin A is especially dangerous for pregnant women as dam-
age to the growing baby can occur. For this reason, high dosesupplements of vitamin A are not usually given to pregnantwomen unless they are exhibiting clinical sign of deficiency(see module 14).
Approaches to the assessment ofmicronutrient deficienciesThere are two main approaches to assessing micronutrient de-ficiencies in emergencies, indirect and direct assessment.
• Indirect assessment involves the estimation of nutrientintakes at a population level and extrapolating from thisthe risk of deficiency and the likely prevalence (rate) andpublic health seriousness of MDD.
• Direct assessment involves the measurement of actualclinical or sub-clinical deficiency in individuals and thenusing that information to give a population estimate ofthe prevalence of the MDD.
Indirect Assessment
The indirect assessment approach involves two stages. Firstly,the dietary intake of the population of concern needs to bemeasured or estimated and, secondly, this intake has to becompared with the nutrient requirements of the population.
Nutrient intake values (NIV) provide guidance about the nutri-ent intakes that healthy individuals require. Countries maypublish different NIV and there may be large differences intheir values.
The NIVs that are currently recommended by WHO and FAOare called Reference Nutrient Intakes (RNI). These RNI werepublished in 2004 and are given in the table in Annex 1. It isimportant to note that older WHO recommendations foremergency affected populations, called Safe Levels of Intake(SLI), are still sometimes used for calculating nutrient require-ments. Using these will give you somewhat different require-ment figures so it is important that this is borne in mind.
To obtain population nutrient requirements, assumptions haveto be made about the demographic profile of the population,the bioavailability of nutrients within the diet, the energy re-quirement of the population, and allowances made for pop-ulation health status.
Assessing these factors in emergencies is not easy and usuallyimpossible in the early stages of the emergency. The use ofthe population planning figures in indirect assessment of therisk of micronutrient deficiencies is therefore usually essential.Table 4 gives the planning figures for a general food rationthat are designed to meet the needs of a population accordingto Sphere. This planning figure should be revised as necessarybased on an assessment of the demographic structure, activitylevel, ambient temperature, and health status of the pop-ulation (see module 11 for details).
TECHNICAL NOTES
5HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
Func
tion
Form
s an
d m
easu
rem
ent u
nits
Sour
ces
Effe
cts
of s
tora
ge a
nd p
repa
ratio
n
Vita
min
A is
a fa
t-so
lubl
e vi
tam
inVi
tam
in A
is p
rese
nt in
food
inRe
tinol
is c
hief
ly fo
und
in d
airy
Both
retin
ol a
nd c
arot
ene
are
stab
le to
requ
ired
for t
he n
orm
al fu
nctio
ning
two
form
s:pr
oduc
ts, l
iver
and
som
e fa
tty
fish.
ordi
nary
coo
king
met
hods
thou
ghof
the
visu
al sy
stem
, gro
wth
and
–Pr
efor
med
vita
min
A (r
etin
ol)
Caro
tene
s are
foun
d in
yel
low
and
som
e lo
sses
may
occ
ur a
tde
velo
pmen
t, m
aint
enan
ce o
fco
ntai
ned
in fo
ods o
f ani
mal
orig
inre
d fru
its a
nd v
eget
able
s, an
d in
tem
pera
ture
s abo
ve 1
00°C
as w
hen
epith
elia
l cel
l int
egrit
y, im
mun
e–
Prov
itam
in A
car
oten
oids
gree
n le
afy
vege
tabl
es, e
spec
ially
butt
er o
r pal
m o
il is
used
for f
ryin
g.fu
nctio
n, a
nd re
prod
uctio
n.(e
.g. b
eta-
caro
tene
) con
tain
ed in
the
gree
n ou
ter l
eave
s. Vi
tam
in A
isVi
tam
in A
is se
nsiti
ve to
oxi
datio
n, so
plan
t foo
dsab
sent
in v
eget
able
oils
with
the
food
s tha
t are
drie
d in
the
sun
lose
Hum
an n
utrit
iona
l req
uire
men
ts a
reex
cept
ion
of fo
rtifi
ed m
arga
rines
muc
h of
thei
r vita
min
A p
oten
cy.
usua
lly e
xpre
ssed
as µ
g of
retin
olan
d re
d pa
lm o
il w
hich
con
tain
Vita
min
A-r
ich
food
s sho
uld
be st
ored
equi
vale
nts (
RE).
Vita
min
A in
prov
itam
in A
.ou
t of d
irect
sunl
ight
.su
pple
men
t cap
sule
s is m
easu
red
inin
tern
atio
nal u
nits
(IU
).1.
0µg
RE =
3.3
IU
Sign
s of
def
icie
ncy
At r
isk
grou
psEf
fect
s of
hig
h in
take
s/to
xici
ty
Vita
min
A d
efic
ienc
y re
sults
in x
erop
htha
lmia
, whi
ch a
ff ect
s the
eye
s.Vi
tam
in A
def
icie
ncy
occu
rs w
idel
yVi
tam
in A
toxi
city
can
be
clas
sifie
dTh
e m
ain
signs
in o
rder
of s
ever
ity a
re:
in d
evel
opin
g co
untr
ies w
ith th
ein
to a
cute
, chr
onic
or t
erat
ogen
ic:
•N
ight
blin
dnes
s (XN
)hi
ghes
t pre
vale
nce
rate
s in
the
–Ac
ute
toxi
city
resu
lts fr
om o
ne o
r•
Bito
t’s sp
ots (
X1B)
Foa
my
accu
mul
atio
ns o
n th
e co
njun
c tiv
a (in
ner e
yelid
s),
regi
ons o
f Sou
th E
ast A
sia a
nd A
frica
.se
vera
l ver
y la
rge
dose
s of
that
ofte
n ap
pear
nea
r the
out
er e
dge
of th
e iri
s.Ch
ildre
n su
fferin
g fro
m m
easle
s,vi
tam
in A
. The
sign
s (vo
miti
ng,
•Co
rnea
l xer
osis
(X2)
Dry
ness
, dul
lnes
s or c
loud
ing
(milk
y ap
pear
ance
) of
diar
rhoe
a, re
spira
tory
infe
ctio
ns,
diar
rhoe
a, b
ulgi
ng fo
ntan
el in
the
corn
ea.
chic
kenp
ox a
nd o
ther
seve
rech
ildre
n, h
eada
ches
) usu
ally
•Ke
rato
mal
acia
(X3)
Sof
teni
ng a
nd u
lcer
atio
n of
the
cor n
ea. T
his i
sin
fect
ions
are
at i
ncre
ased
risk
of
disa
ppea
r afte
r a fe
w d
ays.
som
etim
es fo
llow
ed b
y pe
rfora
tion
of th
e co
rnea
, whi
ch le
ads t
o th
e lo
ssvi
tam
in A
def
icie
ncy.
–Ch
roni
c to
xici
ty o
ccur
s with
of e
ye c
onte
nts a
nd p
erm
anen
t blin
dnes
s. U
lcer
atio
n an
d pe
r fora
tion
may
recu
rrent
exc
essiv
e in
take
s ove
roc
cur a
larm
ingl
y fa
st (w
ithin
a m
att e
r of h
ours
).a
perio
d of
mon
ths t
o ye
ars o
fTh
e le
tter
s and
num
bers
in b
rack
ets,
e.g.
X1B
, are
the
code
s for
the
diffe
rent
exce
ssiv
e do
ses o
f vita
min
A.
form
s of x
erop
htha
lmia
.–
Tera
toge
nic
toxi
city
in p
regn
ant
wom
en m
ay le
ad to
foet
al lo
ss, a
ndVi
tam
in A
def
icie
ncy
in c
hild
ren
is al
so a
ssoc
iate
d w
ith a
n in
crea
sed
risk
and
birt
h de
fect
s. W
omen
who
are
or
seve
rity
of m
orbi
dity
and
incr
ease
d ris
k of
mor
talit
y.m
ay b
ecom
e pr
egna
nt sh
ould
not
cons
ume
mor
e th
an 3
,000
µg R
Epe
r day
.
Tabl
e 3:
Func
tions
, sou
rces
, and
sig
ns o
f def
icie
ncy
for s
elec
ted
mic
ronu
trie
nts
Vitamin A
TECHNICAL NOTES
6 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
Func
tion
Form
s an
d m
easu
rem
ent u
nits
Sour
ces
Effe
cts
of s
tora
ge a
nd p
repa
ratio
n
Thia
min
e is
wat
er-s
olub
le v
itam
inTh
iam
ine
(can
also
be
spel
t Thi
amin
)Th
iam
ine
is w
idel
y di
strib
uted
inLa
rge
loss
es o
f thi
amin
e oc
cur d
urin
gth
at fu
nctio
ns a
s a c
oenz
yme
inex
ists i
n on
e m
ain
form
and
hum
anan
imal
and
pla
nt ti
ssue
s. Th
e on
lym
illin
g or
pou
ndin
g w
hen
the
oute
rth
e m
etab
olism
of c
arbo
hydr
ates
nutr
ition
al re
quire
men
ts a
re u
sual
lyric
h so
urce
s, ho
wev
er, a
re li
ver,
laye
r of c
erea
ls is
lost
. Par
boili
ng ri
cean
d br
anch
ed-c
hain
am
ino
acid
s.m
easu
red
in m
illig
ram
s (m
g)ye
ast a
nd le
gum
es.
prio
r to
mill
ing
redu
ces l
osse
s as
thia
min
e is
driv
en in
to th
e in
terio
r of
the
grai
n. T
here
are
loss
es w
hen
cook
ing
wat
er is
disc
arde
d.
Sign
s of
def
icie
ncy
At r
isk
grou
psEf
fect
s of
hig
h in
take
s/to
xici
ty
Thia
min
e de
ficie
ncy
resu
lts in
ber
iber
i. Fo
ur fo
rms o
f ber
iber
i tha
t are
Popu
latio
ns w
ho c
onsu
me
Thia
min
e ha
s a lo
w to
xici
ty a
ndco
mm
only
due
to lo
w in
take
of v
itam
in B
1 in
dev
elop
ing
coun
trie
sno
n-pa
rboi
led
polis
hed
rice
asth
ere
are
no e
stab
lishe
d up
per l
imits
are
desc
ribed
:a
stap
le a
re a
t risk
. Thi
s in
clud
esfo
r int
ake.
1W
et b
erib
eri:
brea
stfe
d ba
bies
who
se m
othe
rs–
Anor
exia
(los
s of a
ppet
ite) a
nd il
l-def
ined
mal
aise
are
eatin
g a
defic
ient
die
t.–
Tend
erne
ss in
the
calf
mus
cles
and
‘pin
s and
nee
dles
’–
Oed
ema
spre
adin
g fro
m le
gs to
the
face
and
trun
kTh
ose
at ri
sk a
lso in
clud
e th
ose
who
–Re
stle
ssne
ss a
nd b
r eat
hles
snes
s with
rapi
d pu
lse a
nd p
alpi
tatio
nsco
nsum
e di
ets r
ich
in a
nti-t
hiam
ine
2D
ry b
erib
eri:
fact
ors,
such
as s
ulph
ites (
adde
d in
–Po
lyne
urop
athy
(gen
eral
dys
func
tion
of th
e ne
rvou
s sys
tem
)fo
od p
roce
ssin
g), r
aw fi
sh a
ndw
ith lo
ss o
f fee
ling
in th
e fe
et a
nd d
imin
ished
t ouc
h se
nsat
ion
shel
lfish
, and
bet
el n
uts.
–M
uscl
es b
ecom
e pr
ogre
ssiv
ely
was
ted
and
wea
k, a
nd w
alki
ngbe
com
es d
iffic
ult
3In
fant
ile a
cute
car
diac
ber
iber
i:–
Peak
pre
vale
nce
in b
reas
t-fe
d ba
bies
of 1
-3 m
onth
s of a
ge.
–Co
lic-li
ke sy
mpt
oms w
ith sc
ream
ing
bout
s, re
stle
ssne
ss,
anor
exia
and
vom
iting
–O
edem
a–
Brea
thle
ssne
ss w
ith si
g ns o
f hea
rt fa
ilure
and
incr
ease
d pu
lse ra
te–
Hea
rt fa
ilure
eve
ntua
lly le
ads t
o de
ath
4Ap
honi
c be
riber
i:–
Peak
pre
vale
nce
in 4
-6 m
onth
old
chi
ldr e
n. V
oice
cha
nges
with
a c
r yth
at b
ecom
es m
ore
and
mor
e ho
arse
unt
il no
soun
d at
all
is pr
oduc
ed.
Rest
less
ness
and
br e
athl
essn
ess,
Oed
ema
Thia
min
e de
ficie
ncy
also
resu
lts in
Wer
nick
e-Ko
rsak
off s
yndr
ome,
a c
ondi
tion
frequ
ently
ass
ocia
ted
with
chr
onic
alc
ohol
ism
Tabl
e 3:
Func
tions
, sou
rces
, and
sig
ns o
f def
icie
ncy
for s
elec
ted
mic
ronu
trie
nts
(con
tinue
d)
Vitamin B1 (Thiamine)
TECHNICAL NOTES
7HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
Func
tion
Form
s an
d m
easu
rem
ent u
nits
Sour
ces
Effe
cts
of s
tora
ge a
nd p
repa
ratio
n
Ribo
flavi
n is
a w
ater
-sol
uble
vita
min
Ribo
flavi
n ex
ists i
n on
e m
ain
form
and
Ribo
flavi
n is
wid
ely
dist
ribut
ed in
Ribo
flavi
n is
heat
stab
le b
ut c
an b
ere
quire
d fo
r the
nor
mal
func
tioni
nghu
man
nut
ritio
nal r
equi
rem
ents
are
food
but
is in
low
leve
ls in
mos
t foo
dsle
ache
d ou
t of f
ood
durin
g co
okin
gof
man
y en
zym
es a
s wel
l as t
heus
ually
mea
sure
d in
mill
igra
ms (
mg)
that
are
not
of a
nim
al o
rigin
. Ric
han
d is
sens
itive
to li
ght a
nd a
lkal
ine
deve
lopm
ent a
nd m
aint
enan
ce o
fso
urce
s inc
lude
dai
ry p
rodu
cts,
eggs
,so
lutio
ns.
epith
elia
l cel
l int
egrit
y.le
an m
eats
, and
legu
mes
.
Sign
s of
def
icie
ncy
At r
isk
grou
psEf
fect
s of
hig
h in
take
s/to
xici
ty
Ribo
flavi
n de
ficie
ncy
lead
s to
arib
ofla
vino
sis, a
def
icie
ncy
dise
ase
Popu
latio
ns d
epen
dent
on
rice
as a
Ribo
flavi
n is
wel
l tol
erat
ed a
nd h
asch
arac
teris
ed b
y an
gula
r sto
mat
itis.
stap
le. A
ribof
lavi
nosis
is fo
und
a ve
ry lo
w to
xici
ty.
exte
nsiv
ely
in so
uth
Asia
as w
ell a
s in
Angu
lar s
tom
atiti
s affe
cts t
he c
orne
rs o
f the
mou
th w
hich
can
bec
ome
split
or
part
s of A
frica
. Tho
se w
ho a
re a
t risk
crac
ked.
The
lesio
ns m
ay b
ecom
e in
fect
ed w
ith p
atho
gens
such
as c
andi
daha
ve a
lim
ited
avai
labi
lity
of fo
od in
albi
cans
and
hav
e a
whi
tish
appe
aran
ce.
gene
ral a
nd a
low
con
sum
ptio
n of
dairy
pro
duct
s.Ch
eilo
sis, s
calin
g an
d cr
ack i
ng o
f the
surfa
ce o
f the
lips
ma y
be
seen
.
Glo
ssiti
s, in
flam
mat
ion
or sw
ellin
g of
the
tong
ue is
also
som
etim
es r e
port
ed.
Tabl
e 3:
Func
tions
, sou
rces
, and
sig
ns o
f def
icie
ncy
for s
elec
ted
mic
ronu
trie
nts
(con
tinue
d)Vitamin B2 (Riboflavin)
TECHNICAL NOTES
8 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
Func
tion
Form
s an
d m
easu
rem
ent u
nits
Sour
ces
Effe
cts
of s
tora
ge a
nd p
repa
ratio
n
Nia
cin
is w
ater
-sol
uble
and
pla
ysN
iaci
n ex
ists i
n th
e fo
rms o
f nic
otin
icN
iaci
n is
wid
ely
dist
ribut
ed in
pla
ntCo
okin
g ca
uses
litt
le a
ctua
la
cent
ral r
ole
in th
e ut
iliza
tion
ofac
id a
nd n
icot
inam
ide.
It c
an b
ean
d an
imal
food
s, bu
t onl
y in
smal
lde
stru
ctio
n of
nia
cin
but c
onsid
erab
lefo
od e
nerg
y.sy
nthe
sized
from
the
amin
o ac
idam
ount
s, ex
cept
in m
eat (
espe
cial
lyam
ount
s may
be
lost
in th
e co
okin
gtr
ypto
phan
. On
aver
age,
1 m
g of
offa
l), fi
sh, w
hole
mea
l cer
eals
wat
er a
nd ‘d
rippi
ngs’
from
coo
ked
It is
also
kno
wn
as v
itam
in P
Pni
acin
is d
eriv
ed fr
om 6
0 m
g of
die
tary
and
pulse
s.m
eat i
f the
se a
re d
iscar
ded.
(pel
lagr
a pr
even
tativ
e fa
ctor
).tr
ypto
phan
. Nia
cin
is us
ually
mea
sure
das
mill
igra
ms (
mg)
of p
refo
rmed
nia
cin,
or a
s mg
Nia
cin
Equi
vale
nts (
NE)
,w
hich
incl
udes
the
niac
in th
at c
an b
em
ade
by th
e bo
dy fr
om tr
ypto
phan
.AN
E ar
e Av
aila
ble
Nia
cin
Equi
vale
nts
whi
ch a
llow
s for
the
fact
that
nia
cin
from
cer
eal g
rain
s suc
h as
mai
ze h
asa
low
bio
logi
cal a
vaila
bilit
y.
Sign
s of
def
icie
ncy
At r
isk
grou
psEf
fect
s of
hig
h in
take
s/to
xici
ty
Nia
cin
defic
ienc
y re
sults
in p
ella
gra,
whi
ch a
ffect
s the
skin
, gas
tro-
inte
stin
alPo
pula
tions
, who
con
sum
e m
aiz e
as
Hig
h do
ses o
f nic
otin
ic a
cid
can
caus
etr
act a
nd n
ervo
us sy
stem
s. Fo
r thi
s rea
son,
it is
som
etim
es c
alle
d th
e di
seas
eth
eir s
tapl
e w
ithou
t pr o
cess
ing
the
vaso
dila
tatio
n an
d flu
shin
g an
dof
the
3Ds:
derm
atiti
s, di
arrh
oea
and
dem
entia
:m
aize
with
alk
ali t
o re
leas
e ni
acin
,ga
stro
inte
stin
al e
ffect
s suc
h as
–D
erm
atiti
s dev
elop
s as r
edne
ss a
nd it
chin
g on
are
as o
f the
skin
exp
osed
are
at ri
sk o
f dev
elop
ing
pella
gra.
dysp
epsia
, dia
rrho
ea a
ndto
sun
light
cons
tipat
ion.
–Th
e re
dnes
s dev
elop
s int
o a
dist
inct
ive
‘craz
y pa
vem
ent’
patt
ern
and
isPr
oces
sing
mai
ze w
ith a
lkal
i is
sym
met
rical
and
bila
tera
l.co
mm
only
pra
ctic
ed in
Sou
thLo
ng te
rm, v
ery
high
dos
es–
Whe
re d
erm
atiti
s affe
cts t
he n
eck,
it is
som
etim
es te
rmed
‘Cas
al’s
neck
lace
’Am
eric
a bu
t is r
arel
y do
ne in
Afri
ca,
(3-9
g pe
r day
), m
ay re
sult
in–
A di
stin
ctiv
e ‘b
utte
rfly
sign’
arou
nd th
e no
se a
nd e
yes i
s som
etim
es se
enw
here
pel
lagr
a is
ende
mic
.he
pato
toxi
city
.–
Com
plai
nts o
f the
dig
estiv
e sy
stem
incl
uded
dia
rrho
ea, n
ause
a an
dso
met
imes
con
stip
atio
nW
here
nia
cin
rich
food
s, su
ch a
s–
Dist
urba
nces
of t
he n
ervo
us sy
stem
incl
ude
inso
mni
a, a
nxie
t y w
eakn
ess,
pean
uts,
have
not
bee
n pr
ovid
ed in
trem
or, d
epre
ssio
n an
d irr
itabi
lity
emer
genc
y fo
od ra
tions
pel
lagr
a ha
s–
Dem
entia
or d
eliri
um is
som
etim
es se
enoc
curre
d. A
dults
are
at h
ighe
r risk
than
chi
ldre
n an
d w
omen
mor
ePe
llagr
a m
ay b
e fa
tal i
f not
trea
ted,
the
4th
D b
eing
dea
th.
than
men
.
Tabl
e 3:
Func
tions
, sou
rces
, and
sig
ns o
f def
icie
ncy
for s
elec
ted
mic
ronu
trie
nts
(con
tinue
d)
Vitamin B3 (Niacin)
TECHNICAL NOTES
9HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
Func
tion
Form
s an
d m
easu
rem
ent u
nits
Sour
ces
Effe
cts
of s
tora
ge a
nd p
repa
ratio
n
Vita
min
C is
wat
er-s
olub
le a
ndVi
tam
in C
is o
ften
calle
d as
corb
ic a
cid.
Vita
min
C is
wid
ely
dist
ribut
ed in
Vita
min
C is
not
ver
y st
able
and
may
play
s a c
ruci
al ro
le in
the
How
ever
, vita
min
C h
as tw
o ch
emic
alpl
ant a
nd a
nim
al fo
ods a
nd is
foun
dbe
oxi
dise
d du
ring
food
stor
age,
mai
nten
ance
of c
onne
ctiv
e tis
sue,
form
s; as
corb
ic a
cid
and
in h
igh
conc
entr
atio
ns in
frui
ts a
ndpr
epar
atio
n, a
nd c
ooki
ng.
supp
orts
imm
une
func
tion,
and
dehy
droa
scor
bic
acid
.ve
geta
bles
, e.g
. gua
va a
nd c
itrus
frui
t.pr
omot
es w
ound
hea
ling.
It a
lsoen
hanc
es th
e ab
sorp
tion
of ir
onH
uman
nut
ritio
nal r
equi
rem
ents
are
in th
e gu
t.us
ually
exp
ress
ed a
s mg
per p
erso
npe
r day
.
Sign
s of
def
icie
ncy
At r
isk
grou
psEf
fect
s of
hig
h in
take
s/to
xici
ty
Clin
ical
vita
min
C d
efic
ienc
y re
sults
in sc
urvy
. Cla
ssic
sign
s inc
lude
:Po
pula
tions
with
a lo
w in
take
of f
resh
Very
hig
h do
ses (
over
200
0mg
in•
Lack
of e
nerg
y, w
eakn
ess,
irrita
bilit
y, an
d w
eigh
t los
sfru
it an
d ve
geta
bles
. In
food
aid
adul
ts) m
ay re
sult
in n
ause
a an
d•
Swol
len
and
blee
ding
gum
sde
pend
ent p
opul
atio
ns fo
rtifi
eddi
arrh
oea,
inte
rfere
with
the
•Pe
rifol
licul
ar h
aem
orrh
ages
blen
ded
food
s may
be
the
only
antio
xida
nt-p
roox
idan
t bal
ance
in th
e•
Brui
sing
sour
ce o
f vita
min
C.
body
, and
, in
patie
nts w
ith•
Skel
etal
cha
nges
in c
hild
ren
thal
asse
mia
or h
emoc
hrom
atos
is,pr
omot
e iro
n ov
erlo
ad.
If le
ft un
treat
ed, S
curv
y ca
n be
fata
l.
Tabl
e 3:
Func
tions
, sou
rces
, and
sig
ns o
f def
icie
ncy
for s
elec
ted
mic
ronu
trie
nts
(con
tinue
d)Vitamin C
TECHNICAL NOTES
10 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
Func
tion
Form
s an
d m
easu
rem
ent u
nits
Sour
ces
Effe
cts
of s
tora
ge a
nd p
repa
ratio
n
Vita
min
D is
fat-
solu
ble
and
itsVi
tam
in D
is fo
und
in tw
o fo
rms:
Vita
min
D is
mai
nly
synt
hesiz
ed in
Stor
age,
pro
cess
ing
and
prep
arat
ion
activ
e fo
rm is
invo
lved
in c
alci
um•
Ergo
calc
ifero
l (vi
tam
in D
2)th
e bo
dy w
hen
the
skin
is e
xpos
edha
ve n
o ad
vers
e ef
fect
s on
hom
eost
asis
and
bone
•Ch
olec
alci
fero
l (vi
tam
in D
3)to
sunl
ight
. Oth
er n
atur
al d
ieta
ryvi
tam
in D
con
tent
.m
iner
alisa
tion.
Chol
ecal
cife
rol i
s the
form
nat
ural
lyso
urce
s tha
t may
be
impo
rtan
tm
ade
in th
e hu
man
bod
y.in
clud
e sa
lmon
, sar
dine
s, Tu
na, e
gg,
Requ
irem
ents
for V
itam
in D
are
usu
ally
fish
liver
oil,
mus
hroo
m a
ndex
pres
sed
as µ
g pe
r per
son
per d
ay.
dairy
pro
duct
s.
Sign
s of
def
icie
ncy
At r
isk
grou
psEf
fect
s of
hig
h in
take
s/to
xici
ty
Vita
min
D d
efic
ienc
y re
sults
in ri
cket
s, a
defic
ienc
y di
seas
e th
at a
ffect
s you
ngRi
cket
s is e
ndem
ic in
mos
t Mid
dle
Infa
nts a
re m
ost a
t risk
of d
evel
opin
gch
ildre
n. T
ypic
al si
gns i
nclu
de:
East
ern
coun
trie
s in
a ba
nd g
oing
hype
rvita
min
osis
D. H
yper
calc
aem
ia is
•D
elay
ed c
losu
re o
f fon
tane
lles
from
Mor
occo
to P
akist
an a
nd c
anth
e m
ain
adve
rse
affe
ct a
nd m
ay•
Swol
len
wris
ts a
nd a
nkle
soc
cur a
s far
sout
h as
Eth
iopi
a. It
isre
sult
from
dos
es a
bove
45µ
g pe
r day
.•
Squa
red
head
cau
sed
by b
ossin
g of
fron
tal b
one
stru
ctur
eal
so c
omm
on in
par
ts o
f eas
tern
•Sw
ellin
g of
the
ends
of t
he r i
bs (‘
rach
itic
rosa
ry’)
Euro
pe. L
ack
of e
xpos
ure
to th
e su
n•
Dec
reas
ed m
uscl
e to
nein
com
bina
tion
with
a d
iet l
o w in
•Sp
inal
def
orm
itypr
efor
med
vita
min
D a
nd h
igh
inSe
vere
sign
s inc
lude
:ph
ytic
aci
d (e
.g. b
read
) can
cau
se•
Spon
tane
ous f
ract
ures
ricke
ts. P
opul
atio
ns li
ving
in d
eser
t•
Bow
ing
of le
gsar
eas w
here
atm
osph
eric
dus
t act
s•
Teta
ny (t
witc
hing
in fe
et a
nd h
ands
) and
con
vulsi
ons
as a
filte
r for
ultr
a-vi
olet
ligh
t are
Rach
itic
child
ren
show
redu
ced
bone
gro
wth
, are
ana
emic
, and
pro
ne to
susc
eptib
le, p
artic
ular
ly w
hen
peop
lere
spira
tory
infe
ctio
ns. R
icke
ts m
ay a
lso b
e ca
used
by
calc
ium
def
icie
ncy.
stay
insid
e to
avo
id th
e he
at o
f the
day
and
wea
r ext
ensiv
e cl
othi
ng.
Popu
latio
ns w
ho a
r e fo
rced
to re
mai
nin
side
due
to sh
ellin
g or
figh
ting
are
also
at r
isk.
Tabl
e 3:
Func
tions
, sou
rces
, and
sig
ns o
f def
icie
ncy
for s
elec
ted
mic
ronu
trie
nts
(con
tinue
d)
Vitamin D
TECHNICAL NOTES
11HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
Func
tion
Form
s an
d m
easu
rem
ent u
nits
Sour
ces
Effe
cts
of s
tora
ge a
nd p
repa
ratio
n
Iron
has t
hree
maj
or ro
les i
n th
eIro
n is
a ch
emic
al e
lem
ent a
nd is
Mea
t, ce
real
s, ve
geta
bles
and
frui
t all
Iron
is st
able
dur
ing
food
pre
para
tion.
body
. Firs
tly, i
t is n
eces
sary
for t
hefo
und
in tw
o fo
rms i
n fo
od:
cont
ain
iron,
but
hae
m ir
on is
muc
hsy
nthe
sis o
f hae
mog
lobi
n (H
b),
(i)H
eam
iron
: Fou
nd in
ani
mal
sour
cem
ore
easil
y ab
sorb
ed th
an n
on-h
aem
whi
ch c
arrie
s oxy
gen
to th
e bo
dy’s
food
s bou
nd to
hae
m p
rote
in in
iron.
Con
sum
ing
vita
min
C a
t the
cells
and
tran
spor
ts c
arbo
n di
oxid
ebl
ood
and
mus
cle.
sam
e tim
e w
ill in
crea
se a
bsor
ptio
n of
from
the
tissu
es to
the
lung
s.(ii
)Non
-hea
m ir
on: F
ound
mai
nly
iniro
n. E
atin
g ph
ytat
e ric
h fo
ods s
uch
Seco
ndly
, it i
s a c
ompo
nent
of
plan
t foo
ds.
as c
hapa
ttis,
or d
rinki
ng te
a w
hich
myo
glob
in (a
mus
cle
prot
ein)
,H
uman
nut
ritio
nal r
equi
rem
ents
are
cont
ains
pol
y-ph
enol
s, w
ill d
ecre
ase
and
third
ly it
is re
quire
d fo
r the
usua
lly e
xpre
ssed
as m
illig
ram
s (m
g)ab
sorp
tion.
func
tioni
ng o
f man
y en
zym
es.
per d
ay. T
he c
hem
ical
sym
bol f
or ir
onis
Fe a
nd it
exi
sts i
n tw
o io
nic
form
s,as
ferro
us (F
e2+
) and
ferr
ic (F
e3+
) ion
s.
Sign
s of
def
icie
ncy
At r
isk
grou
psEf
fect
s of
hig
h in
take
s/to
xici
ty
Lack
of i
ron
even
tual
ly re
sults
in ir
on-d
efic
ienc
y an
aem
ia. T
ypic
al si
gns a
re:
At ri
sk g
roup
s are
:Th
e ac
ute
toxi
c do
se in
infa
nts i
s•
Pale
con
junc
tivae
(inn
er e
yelid
), na
il be
ds, g
ums,
tong
ue, l
ips a
nd sk
in•
Wom
en o
f chi
ld-b
earin
g ag
eap
prox
imat
ely
20m
g pe
r kg
body
•Ti
redn
ess
(bec
ause
of b
lood
loss
thr o
ugh
wei
ght a
nd th
e le
thal
dos
e is
abou
t•
Hea
dach
esm
enst
ruat
ion)
200-
300m
g pe
r kg.
In a
dults
, a 1
00g
•Br
eath
less
ness
•Pr
egna
nt a
nd b
reas
tfeed
ing
dose
of i
ron
is le
thal
.W
omen
with
seve
re a
naem
ia c
arry
a h
igh
risk
of c
ompl
icat
ions
dur
ing
wom
en (b
ecau
se o
f inc
r eas
ed ir
onch
ildbi
rth.
requ
irem
ents
)•
Babi
es e
xclu
sivel
y br
east
fed
Iron
defic
ienc
y du
ring
infa
ncy
and
early
chi
ldho
od a
lso le
ads t
o im
paire
dbe
yond
the
age
of 6
mon
ths
cogn
itive
dev
elop
men
t. Ec
onom
ic p
rodu
ctiv
ity a
nd e
duca
tiona
l ach
ieve
men
t(b
ecau
se ir
on in
bre
ast m
ilk is
in p
opul
atio
ns is
r edu
ced
by ir
on d
efic
ienc
y an
aem
ia.
inad
equa
te)
•Ba
bies
giv
en c
ow’s
milk
(bec
ause
of in
test
inal
blo
od lo
sses
)•
Wea
ning
-age
chi
ldre
n (b
ecau
seof
inap
prop
riate
wea
ning
die
ts)
•Re
gion
s whe
re m
alar
ia a
ndin
test
inal
par
asiti
c in
f est
atio
n ar
epr
eval
ent a
re a
t risk
.
Tabl
e 3:
Func
tions
, sou
rces
, and
sig
ns o
f def
icie
ncy
for s
elec
ted
mic
ronu
trie
nts
(con
tinue
d)Iron
TECHNICAL NOTES
12 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
Func
tion
Form
s an
d m
easu
rem
ent u
nits
Sour
ces
Effe
cts
of s
tora
ge a
nd p
repa
ratio
n
Iodi
ne is
an
esse
ntia
l con
stitu
ent o
fIo
dine
is a
che
mic
al e
lem
ent.
The
leve
l in
the
soil
dete
rmin
es th
eCo
okin
g re
duce
s the
iodi
ne c
onte
nt,
horm
ones
pro
duce
d by
the
thyr
oid
In fo
rtifi
ed sa
lt it
is fo
und
as P
otas
sium
iodi
ne c
onte
nt o
f pla
nts a
nd a
nim
als.
with
abo
ut h
alf b
eing
lost
dur
ing
glan
d in
the
neck
. In
the
foet
us,
Ioda
te o
r Pot
assiu
m Io
dide
.Ar
eas w
here
freq
uent
floo
ding
or
boili
ng b
ut o
nly
abou
t 20%
bei
ng lo
stio
dine
is n
eces
sary
for t
hedr
aina
ge h
as le
ache
d io
dine
from
the
durin
g fry
ing
or g
rillin
g. Io
dise
d sa
ltde
velo
pmen
t of t
he n
ervo
usH
uman
nut
ritio
nal r
equi
rem
ents
are
envi
ronm
ent a
re p
rone
to io
dine
will
lose
its i
odin
e if
left
unco
vere
d or
syst
em.
usua
lly e
xpre
ssed
as µ
g pe
r per
son
defic
ienc
y. Th
e ric
hest
nat
ural
sour
ceex
pose
d to
hea
t.pe
r day
.of
iodi
ne is
seaf
ood.
The
chem
ical
sym
bol f
or io
dine
is I.
Sign
s of
def
icie
ncy
At r
isk
grou
psEf
fect
s of
hig
h in
take
s/to
xici
ty
Iodi
ne d
efic
ienc
y ca
uses
a ra
nge
of a
bnor
mal
ities
incl
udin
g go
itre
(sw
ellin
g of
Goi
tre is
end
emic
in m
any
Hig
h io
dine
inta
kes c
an c
ause
toxi
cth
e th
yroi
d gl
and
in th
e ne
ck) a
nd c
retin
ism, w
hich
occ
urs i
n th
e of
fspr
ing
ofm
ount
aino
us a
reas
of E
urop
e, A
sia,
mod
ular
goi
tre
and
hype
rthy
roid
ism.
wom
en w
ith se
vere
def
icie
ncy.
the
Amer
icas
and
Afri
ca w
here
ther
eIo
dine
indu
ced
hype
rthy
roid
ism (I
IH)
is lim
ited
acce
ss to
seaf
ood
or io
dise
dm
ay b
e a
part
icul
ar p
robl
em in
aG
oitre
:sa
lt. G
oitre
is a
lso a
ssoc
iate
d w
ith th
epo
pula
tion
that
has
bee
n pr
evio
usly
Gra
de 0
No
palp
able
( can
’t fe
el) o
r visi
bly
enla
r ged
thyr
oid
cons
umpt
ion
of g
oitr o
geni
c fo
ods
defic
ient
and
has
hig
h le
vels
of io
dine
Gra
de 1
A p
alpa
ble
but n
ot v
isibl
y en
lar g
ed th
yroi
d w
ith th
e ne
ck in
such
as c
assa
va. T
he p
reva
lenc
e of
intro
duce
d in
to th
eir d
iet.
a no
rmal
pos
ition
goitr
e in
crea
ses w
ith a
ge a
nd r e
ache
sG
rade
2 A
pal
pabl
e an
d vi
sibly
enl
arge
d th
yroi
d w
ith th
e ne
ck in
a n
orm
ala
peak
dur
ing
adol
esce
nce.
Goi
trea
Posit
ion
tend
s to
affe
ct g
irls m
ore
than
boy
san
d w
omen
mor
e th
an m
en b
ecau
seCr
etin
ism:
of in
crea
sed
activ
ity o
f the
thyr
oid
Ther
e ar
e 2
type
s of c
retin
ismgl
and
durin
g pr
egna
ncy.
Neu
rolo
gica
l cre
tinism
:•
Men
tal d
efic
ienc
y•
Dea
f mut
ism•
Spas
ticity
•At
axia
(lac
k of
mus
cula
r coo
r din
atio
n)
Hyp
othy
roid
or m
yxoe
dem
atou
s cre
tinism
:–
Dw
arfis
m–
Hyp
othy
roid
ism (s
mal
l thy
roid
gla
nd)
Tabl
e 3:
Func
tions
, sou
rces
, and
sig
ns o
f def
icie
ncy
for s
elec
ted
mic
ronu
trie
nts
(con
tinue
d)
Iodine
TECHNICAL NOTES
13HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
Func
tion
Form
s an
d m
easu
rem
ent u
nits
Sour
ces
Effe
cts
of s
tora
ge a
nd p
repa
ratio
n
Zinc
is a
n es
sent
ial m
iner
al th
at is
Zinc
is a
n el
emen
t tha
t is f
ound
inZi
nc is
foun
d in
a w
ide
varie
ty o
fAs
zin
c is
not a
labi
le a
n el
emen
t and
impo
rtan
t in
imm
unity
and
gro
wth
vario
us c
ompo
unds
.fo
ods w
ith ri
ch so
urce
s inc
ludi
ng re
dis
reta
ined
dur
ing
mos
t for
ms o
f foo
dm
eat,
who
le g
rain
s, eg
gs a
nd n
uts.
stor
age,
pro
cess
ing
and
cook
ing.
Hum
an n
utrit
iona
l req
uire
men
ts a
reus
ually
exp
ress
ed a
s mg
per p
erso
npe
r day
.
The
chem
ical
sym
bol f
or z
inc
is Zn
and
it oc
curs
as
a di
vale
nt io
n, Z
n2+.
Sign
s of
def
icie
ncy
At r
isk
grou
psEf
fect
s of
hig
h in
take
s/to
xici
ty
Zinc
def
icie
ncy
is as
soci
ated
with
no-
spec
ific
signs
such
as g
row
th fa
ilure
,Po
pula
tions
with
low
die
t div
ersit
yH
igh
dose
s of e
lem
enta
l zin
c ra
ngin
gdi
arrh
oea,
and
skin
lesio
ns. D
war
fism
and
hyp
ogon
adism
hav
e be
en sh
own
and
diet
s hig
h in
fibr
e an
d/or
phy
tate
from
100
to 1
50m
g/da
y fo
r pro
long
edto
resu
lt fro
m d
efic
ienc
y.(e
.g. v
eget
aria
ns) a
re a
t risk
of
perio
ds in
terfe
res w
ith c
oppe
rde
ficie
ncy.
Sub-
grou
ps a
t par
ticul
arm
etab
olism
and
cau
ses l
o w b
lood
Asse
ssm
ent o
f zin
c st
atus
in p
opul
atio
ns a
nd in
divi
dual
s rem
ains
ver
y di
fficu
lt.ris
k ar
e in
fant
s, ad
oles
cent
s and
copp
er le
vels,
red
bloo
d ce
llIn
dica
tors
of z
inc
defic
ienc
y re
com
men
ded
by th
e In
tern
atio
nal Z
inc
Nut
r itio
npr
egna
nt w
omen
.m
icro
cyto
sis, n
eutro
peni
a, a
ndCo
nsul
tativ
e G
roup
incl
ude:
the
prev
alen
ce o
f ser
um z
inc
conc
entr
atio
n le
ssim
paire
d im
mun
ity. I
nges
ting
larg
erth
an th
e ag
e/se
x/tim
e of
da y
-spe
cific
cut
-offs
; the
pre
vale
nce
(or p
roba
bilit
y)Pa
tient
s with
gen
etic
dise
ases
such
amou
nts (
200
to 8
00m
g/da
y), e
.g. b
yof
zin
c in
take
s bel
ow th
e ap
prop
riate
est
imat
ed a
vera
ge re
quire
men
t (EA
R);
as a
crod
erm
atiti
s ent
erop
athi
ca a
ndco
nsum
ing
acid
ic f o
od o
r drin
k fro
man
d th
e pr
esen
ce o
f a l
ow h
eigh
t-fo
r-ag
e in
20%
or m
ore
of th
e po
pula
tion.
sickl
e ce
ll an
aem
ia a
re a
t spe
cial
risk
a ga
lvan
ized
(zin
c-co
ated
) con
tain
er,
of z
inc
defic
ienc
y.ca
n ca
use
anor
exia
, vom
iting
,an
d di
arrh
oea.
Tabl
e 3:
Func
tions
, sou
rces
, and
sig
ns o
f def
icie
ncy
for s
elec
ted
mic
ronu
trie
nts
(con
tinue
d)Zinc
TECHNICAL NOTES
14 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
The micronutrient content of food aid rations
The micronutrient content of general rations distributed inmany food aid operations has been the subject of criticism fora number of years. Recommended rations generally include acereal, pulses, oil, salt and multi-micronutrient fortified blendedfood.
Fortified blended food has been added to general rations sincethe mid-nineties to improve its micronutrient content. It is alsorecommended by the United Nations High Commissioner forRefugees (UNHCR) and other technical agencies that salt isfortified with iodine, oil with vitamin A and D and wheat andmaize flour with multi-micronutrients. However, analysis of themicronutrient content of standard rations still reveals thepresence of deficiencies in micronutrients.
This problem persists for a number of reasons. Fortification ofthe staple cereal in food aid rations is still uncommon and,where food fortification does happen, the micronutrient mixthat is added is often not appropriately designed to fill thenutrient gaps that exist. Where fortified blended food is in-cluded in general rations it is often included either in low quan-tity or quality and may be inadequate to bring the ration upto standard. Lastly, rations are often supplied in the absenceof any complementary food items such as fresh vegetables orfruit.
A memorandum of understanding (MOU) exists between theWorld Food Programme (WFP) and UNHCR that guides foodaid policy in refugee operations This MOU requires UNHCR tosupply complementary food items where needed. The MOUwas agreed in 2002 and is likely to be revised during 2011.
A MOU (1996) also exists between WFP and UNICEF whichincludes the objectives to “prevent famine-related deaths andmalnutrition including micronutrient deficiencies” and ensure “the provision of a food basket that meets the assessed requirementand is nutritionally balanced and culturally acceptable”.
Despite these agreements between the lead UN agencies,logistic and financial challenges mean that basic rations arelimited, complementary food items are often not supplied, andrations may remain nutritionally inadequate. To illustrate theproblem two rations, recommended in the WFP Food andNutrition Handbook (2005), are analysed in table 5. Both showsevere deficiencies of calcium and riboflavin. The maize basedration is also deficient in vitamin C.
3 Expressed as reference nutrient intakes (RNI) for all nutrients except energy and copper.4 Note that NutVal 2006 and other software tools currently use different population requirement values but future versions are likely to incorporate the values given
in table 4.
Table 4: Current standards for population nutritionalrequirements – to be used for planning purposes in theinitial stage of an emergency
Minimum PopulationNutrient Requirements3, 4
Energy 2,100 kcal
Protein 53g (10% of total energy)
Fat 40g (17% of total energy)
Vitamin A 550µg RAE
Vitamin D 6.1µg
Vitamin E 8.0mg alpha-TE
Vitamin K 48.2µg
Vitamin B1 (Thiamin) 1.1mg
Vitamin B2 (Riboflavin) 1.1mg
Vitamin B3 (Niacin) 13.8mg NE
Vitamin B6 (Pyidoxine) 1.2mg
Vitamin B12 (Cobalamin) 2.2µg
Folate 363µg DFE
Pantothenate 4.6mg
Vitamin C 41.6mg
Iron 32mg
Iodine 138µg
Zinc 12.4mg
Copper 1.1mg
Selenium 27.6µg
Calcium 989mg
Magnesium 201mg
Source: The Sphere Project (2011). Humanitarian Charter and MinimumStandards in Humanitarian Response. Geneva: The Sphere Project.1Alpha-TE – alpha-tocopherol equivalents
RAE – retinol activity equivalents
NE – niacin equivalents
DFE – dietary folate equivalents
TECHNICAL NOTES
15HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
Table 5: Examples of typical general rations and micronutrient deficiencies
Maize-based Rice-based
MAIZE GRAIN, WHITE 400g RICE, POLISHED 350g
BEANS, DRIED 60g LENTILS 100g
VEGETABLE OIL 25g VEGETABLE OIL 25g
CORN SOY BLEND 50g CORN SOY BLEND 50g
SUGAR 15g SUGAR 20g
IODISED SALT 5g IODISED SALT 5g
Ration composition is taken from the WFP (2005) Food and Nutrition Handbook. Rome: WFP
The nutrient adequacy was calculated using the NutVal 2006 spreadsheet calculator.
Vitamin Thia- Ribo- VitaminEnergy Protein Fat Calcium Iron Iodine A mine flavin Niacin C
Ration type Kcal g g mg mg µg µg RE mg mg mg mg
Maize-based 99 116 112 45 101 201 95 229 92 126 88
Rice-based 100 117 77 38 97 201 97 116 50 226 110
Nutrient Adequacy (%)
Monitoring ration contents anddietary intakesEven if a general food ration is correctly designed to meet nutri-ent requirements, the ration that is actually received and con-sumed by the population may differ for several reasons:
• The ration actually distributed on a particulardistribution cycle might differ from the planned one forlogistical reasons. For example, some items might bemissing and be replaced (or not) by others.
• At the distribution point, problems in distributionprocedures might mean that people do not receive theintended quantities of the planned ration.
• Food rations are often not entirely used for consumptionbut may be sold or exchanged for different purposessuch as milling cereals, buying fresh foods andcondiments to diversify the diet, buying essentialnon food items. This might be difficult to quantifywith precision.
• The population might consume other foods in additionto the general ration.
• The size and structure of the beneficiary population maychange due to in or out migration, births, or mortality,making the planning figures obsolete.
Good data on the functioning of a food aid system is essentialfor monitoring the risk of MDD. See figure 1. Assuming thatthe ration has been planned and assessed to be adequate,the three components of a good food aid monitoring systemwill usually include:
1 monitoring of the food aid logistics chain anddistribution process
2 on-site distribution monitoring (OSDM) also sometimescalled food basket monitoring and
3 post-distribution monitoring (PDM) at the householdand market level.
All of these stages are necessary for adequate indirect assess-ment of the risk of micronutrient malnutrition.
The aim of OSDM is to compare the food actually received byfamilies with the planned ration and to follow-up on anyshortfall reported. Protocols for OSDM are laid out in MedecinSans Frontieres (MSF) and UNHCR Guidelines. It is good prac-tice for the agency doing the OSDM to be organisationallyseparate from that involved in food distribution to avoid anyconflict of interest that might arise. Criteria for the interpreta-tion of OSDM data have been laid down by UNHCR. Accordingto the UNHCR guidelines, the cut-offs for acceptable distribu-tions are < 90 per cent or >110 per cent of the planned kcal/person/day. While this is a useful criterion, it takes no accountof differences that may be found in the distribution of differentcommodities and the impact on the micronutrient sufficiencyof the ration.
TECHNICAL NOTES
16 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
Report on Nutrition Survey and an Investigation of the Underlying Causes Of Malnutrition. Camps for Myanmar Refugees from Northern Rakhine State Cox’s Bazar, Bangladesh,August 2003. UNHCR
Since 1978, refugees from Northern Rakhine State, Myanmar, have been living in camps in the Cox’s Bazar area of Bang-ladesh. Nutrition survey data was compiled in 2003 and showed that angular stomatitis, a clinical sign of ariboflavinosis,had been prevalent in children (6-59 months) since at least 1997. In 5 surveys conducted between 1997 and 2003 theprevalence of angular stomatitis varied from 7.0 to 12.6%, indicating chronic riboflavin deficiency.
Analysis of the on-site distribution survey (also called food basket monitoring) data showed that the general rationreceived during 2002 and the first half of 2003 contained an average of only 33% of the population requirement forriboflavin.
Despite the availability of this data no measures were taken at that time to improve the nutrient adequacy of the generalration. However, more recently micronutrient powders and other specialised food supplementation products have beenpiloted in these camps. See module 14 for more information on interventions for micronutrient malnutrition.
Case example 1: Inadequate general rations associated with persistent angular stomatitis in refugees in Bangladesh: 2003
5 NutVal can be downloaded free of charge from http://www.ucl.ac.uk/cihd/6 See INFOODS for a list of software products http://www.fao.org/infoods/software_en.stm
In these methods the survey subjects are asked whether theyhave consumed a specific food item or food group, typicallywithin the last 24 hours or seven days. While it is not possibleto calculate the actual quantities consumed, the diet diversityscore or food variety score approach may be useful for under-standing the sources of micronutrient-rich foods in the dietand for monitoring access to different foods over time.
When food aid is not intended to cover the full needs of thepopulation, a significant amount of micronutrients mightcome from other sources of food. In this case, it might be diffi-cult to find out what these other sources are and in what quan-tities they are being consumed.
When using indirect assessment for population subgroups,certain practical problems may occur. For example, althoughthe RNI are given for different age and gender groups thesemay not always correspond to the groups that are beingassessed.
A variety of software tools have been designed for calculatingthe nutrient content of food aid rations. The most well knowninclude NutCalc, which was developed by EpiCentre for ActionContre le Faim, and NutVal, which was developed for UNHCRand WFP by the University College London Centre for Inter-national Health and Development.5 Many other software pro-ducts for the calculation of nutrient content exist but thesetend not to be specialised for food aid operations.6
NutVal 2006 is currently recommended by WFP and UNHCRfor use in planning and monitoring food aid rations.
Exercises included in part 3 of this module demonstrate theuse of manual calculation and NutVal software for workingout the micronutrient composition of food aid rations.
Post Distribution Monitoring (PDM) should usually be conduct-ed some time after the distribution (roughly 10-20 days afterthe distribution if the distributions are done on a monthlybasis). The PDM looks at the use of the ration and the adequacyof the distribution system. In general, the scope of PDM is quitebroad and includes other relevant food security information.
In many food aid operations the recipient populations are onlypartially dependent on food aid and may have access to a widerange of other commodities. While determining what thesefoods are may be relatively straightforward, gaining an accurateassessment of the quantities available and consumed oftenproves extremely difficult. The various food security methodsthat exist are very valuable for gaining in depth insight intohousehold economies but are somewhat cumbersome to useto try and quantify the risk of micronutrient deficiencies.
Intra household distribution of food is another critical factorthat may affect the risk of certain population groups develop-ing deficiencies. Food distribution practices are often deeplyentrenched in cultural norms and traditions.
RThe accurate measurement of dietary nutrient intake usingweighed intakes, portion sizes or other methods is a challen-ging undertaking in any setting. Such approaches are usuallyinappropriate in refugee or emergency assessments althoughthey have been used in research studies. The measurement ofa diet diversity score or food variety score using food frequencyquestionnaires is, in contrast, a much simpler and more robusttechnique. The resulting scores have been shown to correlatewith anthropometric status and haemoglobin concentration.
TECHNICAL NOTES
17HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
Assessment ofAdequacy
Figure 1: Monitoring points in a food aid system
Commodity sourcing/transport/storage
Utilisation bybeneficiariesRation Planning Distribution
LogisticMonitoring
Food BasketMonitoring
Post-DistributionMonitoring
Anecdotal reports indicate that ration monitoring by itself is arather blunt tool for predicting the risk of MDD outbreaks, part-ly because a population’s access to alternative diets may beunderestimated.
In contrast, examples of the chronic persistence of seriouslydeficient diets together with direct evidence of clinical defi-ciency are also found. For example, in refugee camps in Bangla-desh, food aid rations have been deficient in riboflavin for yearsand there is an associated high prevalence of angular stomatitis– a clear clinical indicator of riboflavin deficiency. Clearly, theevidence from the indirect assessment of the risk of micro-nutrient deficiencies may not always be effective in producingthe necessary changes in food aid programmes.
Direct assessment: Measurement ofmicronutrient deficiencies in individualsand populationsThere are two main approaches that can be used in direct as-sessment of micronutrient deficiencies:
1. Clinical signs and symptoms
2. Biochemical testing
Each approach has potential advantages and disadvantageswhen considered for use in an emergency context.
Clinical signs and symptoms
Observation of clinical signs or the use of questionnaires toidentify symptoms has the advantage of being non-invasive,usually low cost, and is often the most logistically feasible op-tion in remote areas. Clinical signs continue to be used in nutri-tion surveys to try and obtain a prevalence measure of clinicaldeficiency. By definition, the use of clinical signs cannot tell usabout the prevalence of sub-clinical deficiency and the detec-tion of a clinical case usually represents the tip of the icebergof the deficiency problem. See figure 2.
Figure 2: Schematic representation of how clinical and sub-clinical micronutrient deficiency is distributed in a population
Clinical Deficiency
Biochemical Deficiency
At risk
0.3%
29%
The percentage of women affected by pellagra and niacin deficiency is shown as an example.
This data was collected during a survey in the Kuito area of central Angola in 2004.7
7 Seal, AJ. et al. (2007) Low and deficient niacin status and pellagra are endemic in postwar Angola. Am J Clin Nutr 85: 218-224.
TECHNICAL NOTES
18 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
8 Sensitivity is the ability of a test method to detect cases of a disease in people who do actually have the disease. Specificity is the ability of a test method to showa negative result in people without the disease.
An important distinction is between the use of clinical signsand symptoms. Clinical signs are pathological changes thatcan be observed by the surveyor or medical practitioner. Thesubject may or may not be aware of the presence of clinicalsigns. Symptoms are changes that are apparent to the patientor subject but may not always be observable by others. There-fore, in survey work clinical signs rather than symptoms arealmost always used. The use of carer or self reported nightblindness, as an indicator of vitamin A deficiency, is one notableexception.
While clinical signs are very useful they are, with a fewexceptions, often quite non-specific. Goitre is a good exampleof a specific clinical sign of iodine deficiency but even then,goitre may actually result from iodine excess or some otherdisease process, rather than iodine deficiency. Angular stoma-titis is often considered as a specific sign for riboflavin defi-ciency but in fact is associated with at least three nutrientdeficiencies (riboflavin, vitamin B6 and zinc). Nonetheless, thesensitivity and specificity is adequate to make such signs ex-tremely useful for inclusion in surveys.8
Clinical signs are often used in outbreak investigations suchas of scurvy in Afghanistan and pellagra in Angola. Nutritionsurveys quite frequently report the use of clinical signs in ass-essment of deficiencies. Recent examples include surveys ofgoitre in Ivory Coast, and Bitot’s Spots for vitamin A deficiencyin Darfur.
Training staff in correct diagnosis of clinical signs is sometimeschallenging and the use of medically qualified staff is recom-mended whenever possible.
Angular stomatitis is a clinical sign of riboflavin deficiency. It has been measured in nutritional surveys of Bhutaneserefugees living in Nepal camps for a number of years. A nutritional survey conducted in January 2007 found a prevalenceof 1.0% (95% CI 0.4-2.3). The prevalence of this clinical sign had markedly decreased from about 40% in 2000. This mayreflect improvements in the general ration due to the inclusion of blended food and other initiatives. However, thesurvey had been conducted during a different season to the previous one. This made interpretation difficult as theimprovement may just reflect seasonal differences in food availability.http://www.unscn.org/layout/modules/resources/files/NICS_No_13.pdf
Night blindness is a clinical sign of vitamin A deficiency. A survey conducted in the eight most vulnerable areas of Bahjangdistrict, Nepal, in December 2006 measured night blindness in children and their mothers. The reported prevalence was0.5% in children and 15.4% in mothers. The public health significance of this indicator should be assessed in children(preferably between 24-71 months). The prevalence measured indicates a mild public health problem in this situation(see Annex 3 of this module)http://www.unscn.org/layout/modules/resources/files/NICS_No_13.pdf
Box 1: Examples of the use of clinical signs in surveys
When conducting surveys of micronutrient deficiency disea-ses, a clear and simple case definition is essential and the abilityof the survey staff to reliably identity cases should be assessed.For example, pellagra can be assessed using the case definition‘presence of bilateral, symmetrical dermatitis on one or moresun exposed areas of the skin’. Different degrees of vitamin Adeficiency in young children can be assessed using the casedefinitions ‘presence of night blindness’ ‘presence of Bitot’sspots’ ‘presence of corneal xerosis, ulceration or keratomalacia’,‘presence of corneal scars’.
Careful training is essential and where rare conditions are beingsurveyed it is advisable for the survey supervisor to revisit allsuspected cases to confirm the diagnosis. It may be the casethat an adequate case definition cannot be established withthe use of clinical signs by themselves and cut-off values frombiochemical testing may form an important part or the wholeof the case definition.
Biochemical tests
Biochemical tests have the advantage of providing objectivemeasures of micronutrient status. A classification of the differ-ent types of biochemical tests is given in box 2.
The collection of biological samples for testing often presentslogistic, staff training, cold chain, and sometimes, acceptabilitychallenges. Biochemical measurements are also not always asclear-cut, i.e. as sensitive and specific, as might be imagined.Individuals have a wide range of normal values and there arelarge differences between the average values of differenthealthy individuals. There also may be variations according tothe time of day the sample is collected.
TECHNICAL NOTES
19HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
Adapted from: Sauberlich, H.E. (1999) Laboratory Tests for the Assessment of Nutritional Status. CRC Press
1. Static measurements of nutrient under study in blood, urine, or other biological sample (e.g. serum retinol)
2. Measurement of a nutrient metabolite, (e.g. N-methylnicotinamide in urine as an indicator of Niacin status)
3. Biochemical functional test (e.g. enzyme activity in red blood cells for vitamins B1 and B2)
4. Presence of abnormal metabolites (e.g. homocysteine for folate deficiency)
5. Product of nutrient under study (e.g. haemoglobin concentration for iron status)
6. Load or saturation test (e.g. vitamin C in urine after consumption of a high dose tablet)
7. Other procedures (e.g. use of stable isotopes)
Box 2: Types of biochemical tests for detecting nutritional deficiencies
As with all assessment methods, care needs to be taken in in-terpreting results obtained at different times of the year. Theremay be normal fluctuations in micronutrient status due to theaffects of the seasons on food availability and/or infections.For example, it has been shown that the vitamin A status ofpeople in the Gambia varies depending on whether samplesare collected during the wet or dry seasons.
Furthermore, different laboratories may produce results thatdo not agree well. Good quality assurance and quality controltesting is essential and should always be considered whenselecting a laboratory for sample testing.
We also need to be aware that a number of different bioche-mical tests may be available for the same micronutrient, andthese may not necessarily give comparable answers. Forexample, iron status may be quantified by measuring a numberof different components including serum ferritin, serum trans-ferrin receptor, zinc protophorphyrin, and transferrin saturation.At the population level it may also be estimated from haemo-globin concentration. However, each of these measures isfocused on a different part of the iron metabolic pathway so itshould be no surprise that different estimates of deficiencymay be obtained when using these different tests with thesame samples. Again, standardisation of methodologies andcut-off values is essential to allow valid comparisons betweensurveys or studies.
Biochemical measurements might sometimes only give partof an answer. For example, low haemoglobin blood concent-ration indicates anaemia. However, anaemia might be relatedto iron deficiency or to infections, especially malaria or hook-worm, which causes a reduction in haemoglobin blood con-centration, or to inherited conditions such as sickle cell anae-mia or thalassaemia.
Finally, for some of the micronutrients, published methods mayprove very difficult to apply in field based surveys, e.g. becauseof contamination in trace element analysis or the requirementfor extended sample collection time.
In conclusion, before embarking on an assessment involvingbiochemical testing it should be understood that the resultsobtained should not always be regarded as definitive, but theycan provide an invaluable additional tool in reaching conclu-sions. Table 6 provides examples of recent studies where bio-chemical measurements have been taken. A summary of teststhat may be considered for inclusion in surveys is included inAnnex 2.
Operational organizations are, in general, becoming moreaware of the importance of micronutrient malnutrition. Forexample, UNHCR has integrated haemoglobin measurementinto routine nutrition surveys in a number of camps, particu-larly in Tanzania, Algeria and Kenya. Data from these periodicsurveys is used for nutritional surveillance.
Challenge 1: Biochemical assessment in people with infections
When people have an infection, the body launches an acute phase response in which the levels of protein production changeand the concentration of circulating nutrients in the blood is altered. This response may help the body in combating theinfection and is a normal physiological response to inflammation. However, it does mean that if certain indicators of nutritionalstatus are measured in a person with infection they will appear to have a worse nutritional status than they actually do. Thisapplies in particular to serum retinol and ferritin, two popular indicators of vitamin A and iron status. Measurement of acutephase proteins, which are markers of inflammation, can allow for adjustment of the measured nutrient indicators, but there isnot yet a widespread consensus on how adjustments should be applied.
TECHNICAL NOTES
20 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
Table 6: Recent examples of field studies using biochemical testing
Survey or Study Location Nutrient Test
Kassim et al. (2010)9 Kenya – refugees Iodine Urinary iodine excretionfrom Somalia
Seal et al. (2006)10 Angola – post conflict Niacin Urine excretion ofresident population N-methyl nicotinamide
and 2-pyridone
Bennett and Coninx (2005)11 East Africa – prisoners Vitamin C Serum ascorbic acid
Seal et al. (2005)12 Africa – refugees Vitamin A and iron Serum retinol,from various countries Haemoglobin and sTfR
Kemmer et al. (2003)13 Thailand – refugees Iron Haemoglobin andfrom Myanmar zinc protoporphyrin
McGready (2003)14 Thailand – Karen refugees Thiamine and vitamin A ETKAC,breast milk retinol
Blanck et al. (2002)15 Nepal – refugees Riboflavin EGRACfrom Bhutan
9 Kassim, IAR. et al. (2010) Excessive iodine intake during pregnancy in Somali refugees Maternal and Child Nutrition DOI: 10.1111/j.1740-8709.2010.00259.10 Seal AJ. et al. (2007) Low and deficient niacin status and pellagra are endemic in postwar Angola. Am J Clin Nutr. 85 (1): 218-2411 Bennett, M. & Coninx, R. (2005) The mystery of the wooden leg: vitamin C deficiency in East African prisons. Trop.Doct. 35: 81-84.12 Seal A.J. et al (2005) Iron and vitamin A deficiency in long-term African refugees. J Nutr. 135: 808-1313 Kemmer T.M. et al (2003) Iron deficiency is unacceptably high in refugee children from Burma. J Nutr. 133: 4143-914 McGready, R. et al (2003) Delayed visual maturation in Karen refugee infants. Ann.Trop.Paediatr. 23: 193-204.15 Blanck, H. M. t al (2002) Angular stomatitis and riboflavin status among adolescent Bhutanese refugees living in southeastern Nepal. Am.J.Clin.Nutr. 76: 430-435.
• Safety lancets with automatically self-retracting bladesminimise the risk of needle stick injuries and makes reuseand cross-contamination impossible. If venous samplingis strictly necessary then vacuum loaded blood tubescan ease the collection process and a good quality,disposable, sharps collection box permits storage andtransport of waste between survey sites.
• If surveys are being conducted at the household levelthen care must be taken not to contaminate any itemswith blood, remove any waste, and leave the house as itwas found. While sticking plasters should be appliedafter any incisions it is good practice not to use‘child-friendly’ plasters with pictures of animals orthe like, as these may end up being popular andswappable items!
• Disposable or washable plastic cups should be used forurine collection and disposable plastic tubes for faecalsamples. Medical plastic gloves for sample collectorsoften end up comprising the heaviest items in thesurvey supplies list and these and other items may needto be sourced from national or international suppliersa long way distant from the survey site. Good planningand use of a detailed inventory is essential!
Before deciding to use biochemical sampling as a tool in nu-tritional surveys there are a number of important considera-tions to take into account. The points below do not comprisea manual for how-to-do-it but may help to indicate a few ofthe challenges and potential pitfalls.
• Employing the use of good training and technique,and following universal safety precautions helps tominimise the risk of cross-infection with pathogenssuch as HIV and Hepatitis B. Any potential benefits ofconducting the survey need to be balanced againstthe risks to participants and staff. Survey participantsneed to be given full and honest information aboutthe objectives and methods of the survey and informedconsent must be obtained and documented.
• Selection of sampling method and equipment cangreatly reduce the risk and discomfort for both parties.If at all possible, capillary blood collection should beused instead of venous sampling and the samplecollected straight into a specialised tube withthe appropriate anticoagulant or serum separator gel.
TECHNICAL NOTES
21HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
ConclusionsTools for assessing micronutrient status in emergencies areavailable for both indirect and direct assessment approaches.However, there are a number of challenges that limit their im-plementation in the field and careful selection and use is re-quired.
For indirect assessment, it is important to try and gain an un-derstanding of the total dietary intake of micronutrients. Foreffective monitoring of the contribution provided by food aidit is essential to assess the planned ration, the delivery of theplanned ration through the logistics chain, receipt of the rationthrough onsite distribution monitoring, and the use of the ra-tion through post-distribution monitoring.
Direct assessment of micronutrient malnutrition depends onlooking for clinical signs of deficiencies or taking a blood orurine sample for biochemical analysis.
Staff can be trained to recognise the common clinical signs ofmicronutrient deficiency disease by the use of photo-cards.This approach is relatively fast and has a low cost. However,clinical signs are not always specific.
Further improvements in field friendly techniques for thebiochemical assessment of deficiencies are needed. With theexception of the HemoCue photometer, used for the mea-surement of haemoglobin in a finger prick blood sample,collection of biological samples for the analysis of micronu-trients remains challenging. Whilst some techniques have beendeveloped using dried blood spots, direct collection and sto-rage of liquid serum and urine remain a more reliable methodof sample collection. More work on sample collection and sto-rage methods is required to make field surveys easier to con-duct in remote locations.
Information on actual or potential micronutrient malnutritionshould always be crosschecked against other available datato try and obtain the most accurate picture of what is happe-ning.
Micronutrient malnutrition remains a major public health issuethat is far from being eliminated.
• Sample preservation before and during transport/oranalysis is often challenging. Supplies of ice or dry ice areusually required but may be difficult to source. Fridgesand freezers may work intermittently and extra fuel mayneed to be purchased, or solar power laid on to keepthem going constantly without interruption during theduration of the survey. The use of dried blood spots,where a spot of blood is dried onto filter paper and thentransported in a normal envelope provides a, potentially,much simpler solution for sample storage. But cautionis advised unless studies have already been performedto show that the results obtained from samples storedin this way are comparable with results fromliquid samples.
• Finally, formal ethical clearance may be required fromnational and/or international bodies and obtaining thenecessary paperwork may be a time consuming process.
Selection of appropriate population groupsand methods for surveys ofmicronutrient malnutrition
In some situations the careful documentation of individualcase studies may be powerful and sufficient evidence to advo-cate for intervention, especially where the condition is rare,such as for scurvy or pellagra. However, quantification at thepopulation level is often required.
In deciding on a method for assessment of a suspected micro-nutrient problem it is critical to select the appropriate pop-ulation group for study. Table 6 gives guidance on whichgroups to select to gain the most useful indicator. This dependson the relative susceptibility of different age and gendergroups and the availability of assessment methods.
The sample size required for micronutrient surveys is typicallyvery large where clinical signs are used but a lot smaller wherebiochemical measurements are taken. This reflects the relativerarity of overt clinical cases compared to the more prevalentsub-clinical biochemical deficiency that is usually encountered.
Sampling methods may utilise a number of different tech-niques depending on the target population but cluster sam-pling using probability proportional to size will frequently beappropriate and may allow integration with a standard nutri-tion survey (see module 7 for more details about nutrition sur-veys). However, it is important to note that the population sub-group and the required sample size will usually be differentthan that required for a standard anthropometric nutritionsurvey.
Surveillance systems are an alternative to conducting surveysand if micronutrient deficiencies, assessed using either bio-chemical tests or clinical signs, are effectively integrated intoa health information system, monitoring may be relatively lowcost and reliable.
TECHNICAL NOTES
22 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
Annex 1: Recommended nutrient intakes by population groupSource: WHO/FAO (2004): Vitamin and mineral requirements in human nutrition, Second edition: WHO: Geneva
Recommended nutrient intakesa – minerals
Zincc (mg/day)
Calciumb Selenium Magnesium High bio- Moderate bio- Low bio-Group (mg/day) (mg/day) (mg/day) availability availability availability
Infants 300d 26d
0-6 months 400g 6 36h 1.1d 2.8 6.6
7-12 months 400 10 54 0.8d 4.1 8.42.5j
Children1-3 years 500 17 60 2.4 4.1 8.3
4-6 years 600 22 76 2.9 4.8 9.6
7-9 years 700 21 100 3.3 5.6 11.2
AdolescentsFemales 10-18 years 1300k 26 220 4.3 7.2 14.4
Males 10-18 years 1300k 32 230 5.1 8.6 17.1
AdultsFemales 19-50 years 1000 26 220 3.0 4.9 9.8(premenopausal)
Females 51-65 years 1300 26 220 3.0 4.9 9.8(menopausal)
Males 19-65 years 1000 34 260 4.2 7.0 14.0
ElderlyFemales 65+ years 1300 25 190 3.0 4.9 9.8
Males 65+ years 1300 33 224 4.2 7.0 14.0
Pregnant womenFirst trimester m m 220 3.4 5.5 11.0
Second trimester m 28 220 4.2 7.0 14.0
Third trimester 1200 30 220 6.0 10.0 20.0
Lactating women0-3 months 1000 35 270 5.8 9.5 19.0
3-6 months 1000 35 270 5.3 8.8 17.5
7-12 months 1000 42 270 4.3 7.2 14.4
a Recommended nutrient intake (RNI) is the daily intake which meets the nutrient requirements of almost all (97.5%) apparently healthy individuals in an age-and sex-specific population.
b For details, see chapter 4 in WHO/FAO (2004): Vitamin and mineral requirements in human nutrition, Second edition: WHO: Geneva.c For details, see chapter 12 in WHO/FAO (2004): Vitamin and mineral requirements in human nutrition, Second edition: WHO: Geneva.d Breastfed.e Neonatal iron stores are sufficient to meet the iron requirement for the first 6 months in full-term infants. Premature infants and low birth weight infants require
additional iron.f Recommendation for the age group 0-4.9 years.g Cow milk-fed.h Formula-fed.
TECHNICAL NOTES
23HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
Iron (mg/day)
15% Bioavailability 12% Bioavailability 10% Bioavailability 5% Bioavailability Iodine (µg/day)
e e e e 90f
6.2i 7.7i 9.3i 18.6i 90f
3.9 4.8 5.8 11.6 90f
4.2 5.3 6.3 12.6 90f
5.9 7.4 8.9 17.8 120 (6-12yrs)
9.3 (11-14yrs)l 11.7 (11-14yrs)l 14.0 (11-14yrs)l 28.0 (11-14yrs)l 150 (13-18yrs)
21.8 (11-14yrs) 27.7 (11-14yrs) 32.7 (11-14yrs) 65.4 (11-14yrs)
20.7 (15-17yrs) 25.8 (15-17yrs) 31.0 (15-17yrs) 62.0 (15-17yrs)
9.7 (11-14yrs) 12.2 (11-14yrs) 14.6 (11-14yrs) 29.2 (11-14yrs) 150 (13-18yrs)
12.5 (15-17yrs) 15.7 (15-17yrs) 18.8 (15-17yrs) 37.6 (15-17yrs)
19.6 24.5 29.4 58.8 150
7.5 9.4 11.3 22.6 150
9.1 11.4 13.7 27.4 150
7.5 9.4 11.3 22.6 150
9.1 11.4 13.7 27.4 150
n n n n 200
n n n n 200
n n n n 200
10.0 12.5 15.0 30.0 200
10.0 12.5 15.0 30.0 200
10.0 12.5 15.0 30.0 200i Bioavailability of dietary iron during this period varies greatly.j Not applicable to infants exclusively breastfed.k Particularly during the growth spurt.l Pre-menarche.m Not specified.n It is recommended that iron supplements in tablet form be given to all pregnant women because of the difficulties in correctly assessing iron status in pregnancy.
TECHNICAL NOTES
24 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
Recommended nutrient intakesa – water and fat-soluble vitamins
Water-soluble vitamins
Vitamin Cb Thiamine Riboflavin Niacinc Vitamin B6 PantothenateGroup (mg/day) (mg/day) (mg/day) (mg NE/day) (mg/day) (mg/day)
Infants0-6 months 25 0.2 0.3 2i 0.1 1.7
7-12 months 30 0.3 0.4 4 0.3 1.8
Children1-3 years 30 0.5 0.5 6 0.5 2.0
4-6 years 30 0.6 0.6 8 0.6 3.0
7-9 years 35 0.9 0.9 12 1.0 4.0
AdolescentsFemales 10-18 years 40 1.1 1.0 16 1.2 5.0
Males 10-18 years 40 1.2 1.3 16 1.3 5.0
AdultsFemales 19-50 years 45 1.1 1.1 14 1.3 5.0(premenopausal)
Females 51-65 years 45 1.1 1.1 14 1.5 5.0(menopausal)
Males 19-65 years 45 1.2 1.3 16 1.3 (19-50yrs) 5.01.7 (50+yrs)
ElderlyFemales 65+years 45 1.1 1.1 14 1.5 5.0
Males 65+years 45 1.2 1.3 16 1.7 5.0
Pregnant women 55 1.4 1.4 18 1.9 6.0
Lactating women 70 1.5 1.6 17 2.0 7.0
a Recommended nutrient intake (RNI) is the daily intake which meets the nutrient requirements of almost all (97.5%) apparently healthy individuals in an age- andsex-specific population.
b For details, see chapter 7 in WHO/FAO (2004): Vitamin and mineral requirements in human nutrition, Second edition: WHO: Geneva.c NE = Niacin equivalents.d DFE = Dietary folate equivalents; µg of DFE provided = [µg of food folate + (1.7 x µg of synthetic folic acid)].e Vitamin A values are “recommended safe intakes” instead of RNIs. For details, see chapter 2 in WHO/FAO (2004): Vitamin and mineral requirements in human
nutrition, Second edition: WHO: Geneva.f Recommended safe intakes as mg retinol equivalent (RE)/day; conversion factors are as follows:
1µg retinol = 1 RE1µg b-carotene = 0.167µg RE1µg other provitamin A carotenoids = 0.084µg RE.
TECHNICAL NOTES
25HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
Water-soluble vitamins Fat-soluble vitamins
Biotin Vitamin B12 Folated Vitamin Ae,f Vitamin D Vitamin Eg Vitamin Kh
(µg/day) (µg/day) (µg DFE/day) (µg RE/day) (µg/day) (mg alpha-TE/day) (µg/day)
5 0.4 80 375 5 2.7j 5k
6 0.7 80 400 5 2.7j 10
8 0.9 150 400 5 5.0j 15
12 1.2 200 450 5 5.0j 20
20 1.8 300 500 5 7.0j 25
25 2.4 400 600 5 7.5 35-55
25 2.4 400 600 5 10.0 35-55
30 2.4 400 500 5 7.5 55
30 2.4 400 500 10 7.5 55
30 2.4 400 600 5 (19-50yrs) 10.0 6510 (51-65yrs)
2.4 400 600 15 7.5 55
l 2.4 400 600 15 10.0 65
30 2.6 600 800 5 j 55
35 2.8 500 850 5 j 55g Data were not strong enough to formulate recommendations. The figures in the table therefore represent the best estimate of requirements.h For details, see chapter 6 in WHO/FAO (2004): Vitamin and mineral requirements in human nutrition, Second edition: WHO: Geneva.i Preformed niacin.j For details, see chapter 5 in WHO/FAO (2004): Vitamin and mineral requirements in human nutrition, Second edition: WHO: Geneva.k This intake cannot be met by infants who are exclusively breastfed. To prevent bleeding due to vitamin K deficiency, all breast-fed infants should receive vitamin K
supplementation at birth according to nationally approved guidelines.l Not specified.
TECHNICAL NOTES
26 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutrition
Annex 2: Biochemical tests for anaemia and selected nutrient deficiencies
Available Options Recommended Rational
Anaemia 1 Haemoglobin (Hb) Haemoglobin Haemoglobin concentration is a direct2 Haematocrit measure of anaemia. Using a field photo-
meter such as the Hemocue, measures arequick, easy, and can be carried out athousehold level during surveys.
Iron 1 Serum tranferrin receptors (sTfR) sTfR sTfR is affected little by concurrent2 Ferritin infections and is a widely used measure of3 Serum iron iron deficiency. Measurements can be4 Transferrin saturation made on serum samples prepared from a5 Erythrocyte protoporphyrin finger stick capillary blood sample. If ferritin
is used the values obtained have to becontrolled for inflammation status.
Iodine 1 Urinary iodine Urinary Iodine Single samples of urine can be easily2 Neonatal TSH collected from school aged children or3 Thyroglobulin adult women. Samples are stable and it is
not essential to freeze them during tran-sport. Calculation of the median urinaryexcretion is widely accepted as a validmethod of measuring population status.
Vitamin A 1 Serum retinol Serum retinol Serum retinol concentration is a good(Retinol) 2 Retinol binding protein indicator of vitamin A status in populations
3 Relative dose response tests Measurements can be made on serumsamples prepared from a finger stickcapillary blood sample. Samples from thesame finger stick can be used for both ironand vitamin A measurements.
Vitamin B1 1 Erythrocyte Transketolase Activity All methods have The ETKAC assay measures the activity of(Thiamine) Coefficient (ETKAC) disadvantages an enzyme that is dependent on thiamine.
2 Blood concentration of thiamine but ETKAC is A well accepted functional measurement3 Urine excretion generally but requires the collection, centrifugation
regarded as the and freezing of venous blood samples.most validmeasure of status.
Vitamin B2 1 Erythrocyte Glutathione Reductase Both methods The EGRAC assay measures the activity of(Riboflavin) Activity Coefficient (EGRAC) have an enzyme that is dependent on riboflavin.
2 Blood concentration of riboflavin disadvantages A well accepted functional measurementbut have been but requires the collection, centrifugationused successfully and freezing of venous blood samples.in field studies.
Vitamin B3 1 Urinary excretion of metabolites Urinary excretion The excreted metabolites are stable during(Niacin) (1-methyl nicotinamide and 1- storage, samples are easily collected and
methyl-2-Pyridone-5-carboxamide). the method has been successfully used infield surveys.
Vitamin C 1 Serum/plasma concentration Serum Although storage and transport of serum2 Leukocyte concentration concentration samples requires freezing and may be3 Urine excretion problematic, serum vitamin C is an easier
measure and requires lower samplevolume than the isolation of white bloodcells. Urine excretion only reflects recentintake and more research is required toassess how useful it is in populationsurveys.
For a consideration of the sample sizes required for different assessment methods see Annex 3.
TECHNICAL NOTES
27HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
Ann
ex 3
: Pub
lic h
ealt
h cu
t-of
fs fo
r ind
icat
ors
of m
icro
nutr
ient
def
icie
ncie
s an
d ex
ampl
e sa
mpl
e si
zes16
Mic
ronu
trie
nt D
efic
ienc
y In
dica
tor
Reco
mm
ende
d A
geD
efin
ition
of a
Pub
lic H
ealth
Pro
blem
Gro
up fo
rPr
eval
ence
Prev
alen
ce S
urve
ysSe
veri
tyPr
eval
ence
(%)
to d
etec
tPr
ecis
ion
Sam
ple
size
Vita
min
A D
efic
ienc
y17
Nig
ht B
lindn
ess (
XN)18
24-7
1 m
onth
sM
ild>
0 -
< 1
––
–M
oder
ate
≥ 1
- <
51.
000.
500
2,27
5Se
vere
≥ 5
5.00
2.50
043
8Bi
tots
spot
s (X1
B)6-
71 m
onth
sN
ot sp
ecifi
ed>
0.5
0.50
0.25
04,
559
Corn
eal X
eros
is/ul
cera
tion/
6-71
mon
ths
Not
spec
ified
> 0
.01
0.01
0.00
515
3,65
0ke
rato
mal
acia
(X2,
X3A
, X3B
)
Corn
eal s
cars
(XS)
6-71
mon
ths
Not
spec
ified
> 0
.05
0.05
0.02
530
,718
Brea
st m
ilk re
tinol
(≤ 1
.05
(mol
/L)
Mot
hers
Mild
< 1
0–
––
Mod
erat
e≥
10
- < 2
510
.00
5.00
020
8Se
vere
≥ 2
525
.00
7.50
022
1Se
rum
retin
ol (≤
0.7
(mol
/L)
6-71
mon
ths
Mild
≥ 2
- <
10
2.00
1.00
01,
128
Mod
erat
e≥
10 -
< 2
010
.00
5.00
020
8Se
vere
≥ 2
020
.00
7.50
016
4
Iodi
ne D
efic
ienc
y19
Goi
tre (v
isibl
e +
pal
pabl
e)Sc
hool
-age
chi
ldre
nM
ild5.
0 -1
9.9
5.00
2.50
043
8M
oder
ate
20.0
-29.
920
.00
7.50
016
4Se
vere
≥ 3
0.0
30.0
010
.000
121
Med
ian
urin
ary
iodi
ne (µ
g/l)
Scho
ol-a
ge c
hild
ren
Adeq
uate
100-
19920
N/A
21N
/A≥
40
Mild
50-9
9N
/AN
/A≥
40
Mod
erat
e20
-49
N/A
N/A
≥ 4
0Se
vere
< 2
0N
/AN
/A≥
40
16Ca
lcul
atio
ns w
ere
perfo
rmed
with
Epi
Info
6.0
4 an
d ar
e ba
sed
on a
pop
ulat
ion
size
of 5
00,0
00 a
nd a
des
ign
effe
ct o
f 1.5
for c
lust
er su
rvey
s17
‘Indi
cato
rs fo
r Ass
essin
g Vi
tam
in A
Def
icie
ncy a
nd th
eir A
pplic
atio
n in
Mon
itorin
g an
d Ev
alua
ting
Inte
rven
tion
Prog
ram
mes
’ p.7
(199
6) W
orld
Hea
lth O
rgan
isatio
n, G
enev
a W
HO
/NU
T/96
.10
18Th
e le
tter
cod
es b
egin
ning
in X
, XN
, X1B
etc
. are
shor
than
d fo
r the
diff
eren
t typ
es o
f xer
opht
halm
ia19
‘Ass
essm
ent o
f iod
ine
defic
ienc
y diso
rder
s and
mon
itorin
g th
eir e
limin
atio
n. A
gui
de fo
r pr o
gram
me
man
gers
.’ (20
07) 3
rd E
d., C
hapt
er 4
, WH
O/U
NIC
EF/IC
CID
D20
Figu
res g
iven
her
e ar
e fo
r the
con
cent
ratio
n of
iodi
ne in
ur in
e, n
ot th
e pr
eval
ence
.21
N/A
– N
ot a
pplic
able
TECHNICAL NOTES
28 HTP, Version 2, 2011
MODULE 4 Micronutrient malnutritionPu
blic
hea
lth c
ut-o
ffs fo
r ind
icat
ors
of m
icro
nutr
ient
def
icie
ncie
s an
d e x
ampl
e sa
mpl
e si
zes
(con
tinue
d)
Mic
ronu
trie
nt D
efic
ienc
y In
dica
tor
Reco
mm
ende
d A
geD
efin
ition
of a
Pub
lic H
ealth
Pro
blem
Gro
up fo
rPr
eval
ence
Prev
alen
ce S
urve
ysSe
veri
tyPr
eval
ence
(%)
to d
etec
tPr
ecis
ion
Sam
ple
size
Iron
Def
icie
ncy22
Anae
mia
(Non
-pre
gnan
t wom
enW
omen
, Chi
ldre
nLo
w5-
205.
02.
543
8ha
emog
lobi
n <
12.0
g/dl
; chi
ldre
nM
ediu
m20
-40
20.0
7.5
164
6-59
mon
ths <
11.0
g/dl
)23H
igh
≥ 4
040
.010
.013
9
Berib
eri24
Clin
ical
Sig
nsW
hole
pop
ulat
ion
Mild
≥ 1
cas
e &
< 1
%–
––
Mod
erat
e1-
41.
00.
52,
275
Seve
re≥
55.
02.
543
8Th
iam
ine
pyro
phos
phat
e ef
fect
Who
le p
opul
atio
nM
ild5-
195.
02.
543
8(T
PPE)
≥ 2
5%M
oder
ate
20-4
920
.07.
516
4Se
vere
≥ 5
050
.012
.010
1U
rinar
y th
iam
ine
per g
cre
atin
ine
Who
le p
opul
atio
nM
ild5-
195.
02.
543
8(A
ge g
roup
spec
ific
cut-
offs
)M
oder
ate
20-4
920
.07.
516
4Se
vere
≥ 5
050
.012
.010
1
Brea
st m
ilk th
iam
ine
(< 5
0 (g
/L)
Lact
atin
g w
omen
Mild
5-19
5.0
2.5
438
Mod
erat
e20
-49
20.0
7.5
164
Seve
re≥
50
50.0
12.0
101
Die
tary
inta
ke (<
0.3
3mg/
1000
kca
l)W
hole
pop
ulat
ion
Mild
5-19
5.0
2.5
438
Mod
erat
e20
-49
20.0
7.5
164
Seve
re≥
50
50.0
12.0
101
Infa
nt m
orta
lity
Infa
nts 2
-5 m
onth
sM
ildN
o in
crea
se–
––
in ra
tes
Mod
erat
eSl
ight
pea
k–
––
in ra
tes
Seve
reM
arke
d pe
ak–
––
in ra
tes
22Cl
assif
icat
ion
prop
osed
in:‘
The
Man
agem
ent o
f Nut
ritio
n in
Maj
or E
mer
genc
ies’
(200
0) W
orld
Hea
lth O
rgan
isatio
n, G
enev
a23
Cut-
offs
are
giv
en fo
r < 1
000m
and
ma y
nee
d to
be
adju
sted
acc
ordi
ng to
age
, sex
and
alti
tude
24Cr
iteria
pro
pose
d in
: ‘Th
iam
ine
Def
icie
ncy a
nd it
s Pre
vent
ion
and
Cont
rol in
Maj
or E
mer
genc
ies’
p.14
(199
9) W
HO
/UN
HCR
, Gen
eva
WH
O/N
HD
/99.
13
TECHNICAL NOTES
29HTP, Version 2, 2011
MODULE 4Micronutrient malnutrition
25Pr
ovisi
onal
crit
eria
sugg
este
d in
‘Pel
lagr
a an
d its
Pre
vent
ion
and
Cont
rol in
Maj
or E
mer
genc
ies’
WH
O/U
NH
CR, 2
000,
WH
O/N
HD
/00.
10 a
nd ‘M
anag
emen
t of N
utrit
ion
in M
ajor
Em
erge
ncie
s’, W
orld
Hea
lth O
rgan
isatio
n, G
enev
a, 2
000
26Al
thou
gh th
e us
e of
the
urin
ary
ratio
of 2
-pyr
idon
e:N
-met
hyl n
icot
inam
ide
is pr
ovisi
onal
ly re
com
men
ded
in W
HO
pub
licat
ions
, sub
sequ
ent r
esea
rch
has d
emon
stra
ted
that
whe
n ur
ine
is co
llect
ed a
t a si
ngle
tim
e po
int,
such
as d
urin
g a
surv
ey, t
he m
etab
olite
ratio
is n
ot a
stab
le in
dica
tor o
f nut
ritio
nal s
tatu
s.27
Rece
nt su
rvey
wor
k fro
m a
n ar
ea o
f Ang
ola
whe
r e p
ella
gra
is en
dem
ic h
as su
gges
ted
that
this
cut-
off n
eeds
to b
e re
vise
d up
war
ds to
1.6
mg/
g cr
eatin
ine,
and
that
the
mea
sure
men
t of t
he 2
-pyr
idon
e m
etab
olite
pro
vide
s is
a m
ore
relia
ble
anal
ytic
al m
easu
r e. (
Seal
et a
l. (20
07) ‘
Low
and
def
icie
nt n
iaci
n st
atus
and
pel
lagr
a ar
e en
dem
ic in
pos
t war
Ang
ola’
Am
J Cl
in N
utr 8
5, 2
18-2
24)
28Pr
ovisi
onal
crit
eria
sugg
este
d in
‘Scu
rvy a
nd it
s Pre
vent
ion
and
Cont
rol in
Maj
or E
mer
genc
ies’
p.9
(199
9) W
orld
Hea
lth O
rgan
isatio
n/U
NH
CR W
HO
/NH
D/9
9.11
Publ
ic h
ealth
cut
-offs
for i
ndic
ator
s of
mic
ronu
trie
nt d
efic
ienc
ies
and
exam
ple
sam
ple
size
s (c
ontin
ued)
Mic
ronu
trie
nt D
efic
ienc
y In
dica
tor
Reco
mm
ende
d A
geD
efin
ition
of a
Pub
lic H
ealth
Pro
blem
Gro
up fo
rPr
eval
ence
Prev
alen
ce S
urve
ysSe
veri
tyPr
eval
ence
(%)
to d
etec
tPr
ecis
ion
Sam
ple
size
Pella
gra25
Clin
ical
Sig
ns (D
erm
atiti
s) in
surv
eyed
Who
le p
opul
atio
n or
Mild
≥ 1
cas
e &
< 1
%–
––
age
grou
pw
omen
>15
yea
rsM
oder
ate
1-4
1.0
0.5
2,27
5Se
vere
≥ 5
5.0
2.5
438
Urin
ary
N-m
ethy
l nic
otin
amid
eW
hole
pop
ulat
ion
orM
ild5-
195.
02.
543
8<
0.5
mg/
g cr
eatin
ine26
, 27
wom
en >
15 y
ears
Mod
erat
e20
-49
20.0
7.5
164
Seve
re≥
50
50.0
12.0
101
Die
tary
inta
ke o
f nia
cin
equi
vale
nts
Who
le p
opul
atio
n or
Mild
5-19
5.0
2.5
438
<5
mg/
day
wom
en >
15 y
ears
Mod
erat
e20
-49
20.0
7.5
164
Seve
re≥
50
50.0
12.0
101
Scur
vy28
Clin
ical
sign
sW
hole
pop
ulat
ion
Mild
≥ 1
cas
e &
< 1
%–
––
Mod
erat
e1-
41.
00.
52,
275
Seve
re≥
55.
02.
543
8D
efic
ient
seru
m a
scor
bic
acid
Who
le p
opul
atio
nM
ild10
-29
10.0
5.0
208
(< 0
.2m
g/10
0ml)
Mod
erat
e30
-49
30.0
10.0
121
Seve
re≥
50
50.0
12.0
101
Low
seru
m a
scor
bic
acid
Who
le p
opul
atio
nM
ild30
-49
30.0
10.0
121
(< 0
.3m
g/10
0ml)
Mod
erat
e50
-69
50.0
12.0
101
Seve
re≥
70
70.0
15.0
54