VITAMIN B (1,6,12)Ravan Rashid Mohammed (GM)

Classification Of Vitamins:

The Vitamins Overview:

• Vitamins differ from carbohydrate, fat and protein in structure, function and food contents.

• Vitamins are similar to the energy-yielding nutrients in that they are vital to life, organic and available from foods.

• Both deficiencies and excesses of the vitamins can affect health.

• The organic nature of vitamins means they can be destroyed by exposure to light, oxidation, cooking, and storage.

The Vitamins Overview:

• Solubility and storage• Fat-soluble vitamins (vitamins A, D, K and E) are

absorbed first into the lymph, then the blood. • Many require protein carriers.• Stored in cells associated with fat• Less readily excreted• Needed periodically

The Vitamins Overview:• Solubility and storage• Water-soluble vitamins (B vitamins and vitamin C)

are absorbed directly into the blood and travel freely.• Circulate freely• Excreted in urine• Needed frequently

The Vitamins Overview:

• Toxicity• Water-soluble vitamins can reach toxic levels

with supplement use.• Fat-soluble vitamins are likely to reach toxic

levels with supplement use.• DRI Committee has established Tolerable

Upper Intake Levels for niacin, vitamin B6, folate, choline and vitamin C.

Vitamins B Group:• Vitamin B1 (Thiamine) • Vitamin B2 (Riboflavin) • Vitamin B3 or Vitamin P or Vitamin PP (Niacin) • Vitamin B5 (Pantothenic acid) • Vitamin B6 (Pyridoxine and Pyridoxamine) • Vitamin B7 or Vitamin H (Biotin) • Vitamin B9 or Vitamin M and Vitamin B-c (

Folic acid)• Vitamin B12 (Cyanocobalamin)

VITAMIN B1 (THIAMINE) • Composed of a substituted pyridine and

thiazole ring.• Thiamine (vitamin B1) was the first of the

water-soluble B-vitamin family to be discovered.

• The vitamin is easily destroyed by heat.

Active Form Of Vitamin B1:

• The active form of vitamin B1 (thiamine) isthiamine pyrophosphate (TPP), which is formed by the transfer of a pyrophosphate group from ATP to thiamine.

The Main Functions Of Vitamin B1 Are:• Brain development and function including healthy

functioning of the nervous system, alertness, and emotions / mood.

• Conversion of food into energy via normal metabolism - also promotes a healthy appetite and digestion

• (General) energy boost and overall sense of well-being, which can even include reduced blood pressure in some cases.

• Coenzyme for four enzymes :• pyruvate dehydrogenase• α-ketoglutarate dehydrogenase• branched-chain amino acid α-ketoacid dehydrogenase• transketolase

Thiamin Deficiency:

Dietary deficiency is rare because vitamin B1 is found in most foods. Moderate deficiency may induce anxiety, depression and irritability. Extreme Deficiency can lead to:• Beriberi - a disease that involves nerve inflammation, muscular

weakness and, in extreme cases, heart failure.• Wernicke's encephalopathy - which is associated with alcoholism• Korsakoff's psychosis - a neurological disorder whose symptoms

include: anterograde amnesia, retrograde amnesia, confabulation (i.e. "invented memories"), inability to make much contribution to conversations, lack of insight, apathy and indifference to change.

Beriberi:The most important use of thiamine is to treat beriberi, which is caused by not getting enough thiamine in your diet. Symptoms include:• Swelling, tingling, or burning sensation in the hands and feet• Confusion• Trouble breathing because of fluid in the lungs• Uncontrolled eye movements (nystagmus)People in the developed world usually do not get beriberi because foods such as cereals and breads are fortified with vitamin B1.

Signs Of Excessive Intake Of Vitamin B1:Excessive doses (possibly by injection) may lead to very rare toxic symptoms such as:• Headaches• Allergic reactions• Disturbance of heart beat• Nervousness• Shaking & Swellings• Insomnia• Dermatitis

SOURCES OF VITAMIN B1:• There are many different types of foods that include some

vitamin B1.Examples of sources of vitamin B1 follow below:

• Brown rice• Yeast• Meat e.g. pork and liver• Nuts e.g. peanuts• Beans• Peas• Potatoes• and various vegetables such as asparagus, cauliflower and kale.

VITAMIN B6:

• Vitamin B6 is a water-soluble vitamin. It is one of the vitamin B-complex group of vitamins.

There are several forms of vitamin B6:• pyridoxine• pyridoxal• pyridoxamine

Active Form Of Vitamin B6:

• The three main forms of vitamin B6 (i.e. pyridoxine, pyridoxal and pyridoxamine) can be converted to the biochemical pyridoxal phosphate - which is sometimes written pyridoxal 5'-phosphate and is sometimes abbreviated to "PLP". 

Functions Of Vitamin B6:Vitamin B6 has many functions, of which the main functions of vitamin B6 are:• Helps with conversion of foods into energy via working with enzymes• Promotion of healthy skin, teeth, and gums and nerves.• Formation of red blood cells• Formation of hormones involved in the functioning of the brain e.g.

serotonin and melatonin, which affect mood and the sleep cycle.• Supports the immune system, hence the body's resistance to disease• Vitamin B6 is needed in order for vitamin B12 to be absorbed by the body.• Coenzyme for enzymes, particularly in amino acid metabolism

Deficiencies Of Vitamin B6: Dietary deficiency of vitamin B6 is rare, but can lead to:• Loss of appetite• Hypochromic, microcytic anaemia• Fatigue• Nervousness• Insomnia• Convulsions• Depression• Memory problems

Signs Of Excessive Intake Of Vitamin B6:

• Toxic effects of vitamin B6 are rare. However, intake of high doses of vitamin B6 over an extended period of time has been associated with development of sensory neuropathy, i.e. damage to the body's sensory nerves. An example of an effect of this is the sensation of "pins and needles".

Sources Of Vitamin B6:Many foods include some vitamin B6. Examples of sources of vitamin B6 include:• Whole grains (wheat or corn) e.g. whole-grain cereals• Wheatgerm• Wholemeal bread• Meat incl. poultry (e.g. chicken) and liver• Fish• Milk• Nuts• Bananas• Green vegetables, e.g. brussel sprouts• Potatoes

VITAMIN B12

• There are several vitamins.Vitamin B12 is also known as cobalaminand cyanocobalamin and is one of the group of B vitamins.

Active Forms Of Vitamin B12:

• There are two active forms of vitamin B12:• deoxyadenosylcobalamin, and• methylcobalamin

Functions Of Vitamin B12: • Promotes growth, especially healthy growth in children - vitamin B12 is

needed for cell division and the production of erythrocytes (i.e. red blood cells)

• Prevents anaemia - which results from insufficient red blood cells. Pernicious anaemia is sometimes treated with injections of vitamin B12.

• Health of nervous system - via maintenance of myelin in the nervous system

• Synthesis of nucleic acids• Production of serotonin and dopamine 

This function is why increased intake of vitamin B12 may help to alleviate depression and anxiety.

• Coenzyme for two enzymes:• Methylmalonyl CoA mutase.• Homocysteine methyltransferase.

 Deficiencies Of Vitamin B12:

• Affects most body tissues, especially those containing rapidly dividing cells

• Pernicious anaemia• Degeneration of the nervous system (incl. loss of sensation

and poor co-ordination)• Tongue infections

Signs Of Excessive Intake Of Vitamin B12:

• Although vitamin B12 is not considered toxic, there have been rare reports of allergic reactions to injections of high-doses of vitamin B12.

Sources Of Vitamin B12:The sources of vitamin B12 come from animals so there are concerns about deficiency in vegans.• Liver is an especially good source• Meat e.g. beef or pork• White fish• Eggs (one egg per day is enough for RDA)• Milk / Dairy products• Brewers Yeast / Yeast Extract• Some breakfast cereals are fortified with vitamin B12