micronutrients: vitamins and mineralshomepages.wmich.edu/~sayers/3970 ch09 f09.pdf11/5/2009 13 •...

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REVIEW: Water & FluidsREVIEW: Water & Fluids

•• Fluid Fluid compartmentscompartments

•• Convection, radiationConvection, radiation,,

•• Mechanisms for dehydration’s adverse Mechanisms for dehydration’s adverse performance effectsperformance effects

•• Why electrolytes are added to sports drinksWhy electrolytes are added to sports drinks

•• Main purpose of fluid ingestion during exerciseMain purpose of fluid ingestion during exercise

The Micronutrients:Vitamins and MineralsThe Micronutrients:

Vitamins and Minerals

Chapter 9 Chapter 9

HPER 3970Dr. Ayers (courtesy of Dr. Cheatham)

HPER 3970Dr. Ayers (courtesy of Dr. Cheatham)

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Water and Fat Soluble VitaminsWater and Fat Soluble Vitamins

•• Organic compounds that are needed in very small dietary quantities Organic compounds that are needed in very small dietary quantities

•• Essential for:Essential for:G h d d lG h d d l–– Growth and developmentGrowth and development

–– Specific metabolic reactionsSpecific metabolic reactions

•• Vitamins are not produced by the bodyVitamins are not produced by the body–– Exceptions: Vitamin D (sun), K, some B (GI)Exceptions: Vitamin D (sun), K, some B (GI)

d d dd d d•• 13 compounds are considered vitamins13 compounds are considered vitamins–– Water soluble: C, BWater soluble: C, B11 (thiamin), B(thiamin), B22 (riboflavin), B(riboflavin), B33 (niacin), B(niacin), B66 (pyridoxine), (pyridoxine),

pantothenicpantothenic acid, biotin, folic acid, Bacid, biotin, folic acid, B1212 ((cobalamincobalamin))

–– Fat soluble: A (retinol), D (Fat soluble: A (retinol), D (calciferolcalciferol), E (), E (tocopheroltocopherol), K (), K (menadionemenadione))


Vitamin deficiencies reduce body function and impair health & exercise performance

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Table 9‐2


Table 9‐3

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Table 9‐4

•• Effect of exercise on vitamin requirements:Effect of exercise on vitamin requirements:–– Inadequate vitamin status is associated withInadequate vitamin status is associated with


Inadequate vitamin status is associated with Inadequate vitamin status is associated with impaired exercise performanceimpaired exercise performance

–– Theoretically, exercise can induce a marginal Theoretically, exercise can induce a marginal vitamin status (deficiency):vitamin status (deficiency):•• Decreased absorption from digestive tractDecreased absorption from digestive tract

•• Increased excretion in sweat, urine, and fecesIncreased excretion in sweat, urine, and feces

•• Increased turnover (degradation)Increased turnover (degradation)

•• Increased requirements because of biochemical Increased requirements because of biochemical adaptations to trainingadaptations to training

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•• Assessing vitamin status:Assessing vitamin status:•• Biopsy samplesBiopsy samples

•• Blood cells or plasmaBlood cells or plasma


•• Blood cells or plasmaBlood cells or plasma

•• Dietary analysisDietary analysis

–– Very little evidence that athletes’ vitamin intakes are inadequate based on Very little evidence that athletes’ vitamin intakes are inadequate based on the RDAthe RDA

•• Recommended intake of vitamins:Recommended intake of vitamins:–– EAR, RDI/RDA, AIEAR, RDI/RDA, AI

–– Data to determine these values often times did not include athletesData to determine these values often times did not include athletes

–– With balanced diet and proper caloric intake, most athletes should get With balanced diet and proper caloric intake, most athletes should get adequate vitamin intake from food (see next slide)adequate vitamin intake from food (see next slide)

–– Individuals at risk:Individuals at risk:•• LowLow‐‐energy or unbalanced dietenergy or unbalanced diet

•• VegetariansVegetarians


As shown for thiamin and

Fig 9‐1vitamin C, athletes’ vitaminintakes are correlated withenergy intake up to 4,800 kcal/day.

Balanced diet = adequate vitamins

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•• Dietary surveys of vitamin intakes in elite Dietary surveys of vitamin intakes in elite athletes:athletes:


––Athletes do not always consume a wellAthletes do not always consume a well‐‐balanced dietbalanced diet•• Risk due to fatiguing and timeRisk due to fatiguing and time‐‐consuming consuming demands of trainingdemands of training

M i kM i k•• Most at risk:Most at risk:–– Female adolescent athletesFemale adolescent athletes

–– Athletes attempting to maintain low body weights Athletes attempting to maintain low body weights (wrestlers, gymnasts, ballet dancers)(wrestlers, gymnasts, ballet dancers)


As shown for

Fig 9‐3

As shown for vitamin C and B2, endurance athletes’ intakes are adequate and were correlated withhigher total energy intakes.

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Macro‐ and MicromineralsMacro‐ and Microminerals

•• A mineral is an inorganic compound found in nature A mineral is an inorganic compound found in nature and are essential to life processesand are essential to life processes

•• 7 major 7 major macromineralsmacrominerals (each = @ least 0.01% total body mass)(each = @ least 0.01% total body mass)::–– Potassium, sodium, chloride, calcium, Potassium, sodium, chloride, calcium, mangesiummangesium, , phosphorus, sulfurphosphorus, sulfur

•• 10 major 10 major micromineralsmicrominerals (trace elements):(trace elements):–– Chromium, cobalt, copper, fluorine, iodine, iron, manganese, Chromium, cobalt, copper, fluorine, iodine, iron, manganese, molybdenum selenium zincmolybdenum selenium zincmolybdenum, selenium, zincmolybdenum, selenium, zinc

•• Inadequate mineral nutrition has been associated Inadequate mineral nutrition has been associated with:with:–– Anemia, cancer, diabetes, hypertension, osteoporosis and Anemia, cancer, diabetes, hypertension, osteoporosis and tooth decaytooth decay


Table 9‐6

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Table 9‐7

↓


↓

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•• Recommended intake of minerals:Recommended intake of minerals:–– RDA for 7 minerals and AI for 5RDA for 7 minerals and AI for 5


Table 9‐8


Table 9‐9

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•• Effect of exercise on mineral requirements:Effect of exercise on mineral requirements:


Fig 9‐4

•• Dietary surveys of mineral intakes by Dietary surveys of mineral intakes by elite athletes:elite athletes:


elite athletes:elite athletes:•• More difficult than vitaminsMore difficult than vitamins

•• Dietary records, plasma levelsDietary records, plasma levels

––Iron, zinc, calcium, and magnesium may Iron, zinc, calcium, and magnesium may b f i ll fb f i ll fbe of some concern especially for young be of some concern especially for young athletes and women athletes of all agesathletes and women athletes of all ages

––Functions by categoriesFunctions by categories, not list of , not list of micronutrientsmicronutrients

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Micronutrients Form the Building Blocks of TissuesMicronutrients Form the Building Blocks of Tissues

•• Calcium, phosphorus, Calcium, phosphorus, flourineflourine important in important in bones and bones and teethteeth

•• Vitamin D is required for normal absorption of dietary Vitamin D is required for normal absorption of dietary calciumcalcium

•• Vitamin C is required for the production of collagen Vitamin C is required for the production of collagen (connective tissue and cartilage)(connective tissue and cartilage)

•• Calcium:Calcium:–– Role of menstruation and estrogenRole of menstruation and estrogen

•• Chronically low plasma estrogen levelsChronically low plasma estrogen levels

–– If amenorrhea is present:If amenorrhea is present:•• 120% of RDA is recommended120% of RDA is recommended

•• Prevent or limit the actions of freePrevent or limit the actions of free‐‐radicals, usually by radicals, usually by removing their unpaired electrons and converting them to removing their unpaired electrons and converting them to something less reactivesomething less reactive

Micronutrients as AntioxidantsMicronutrients as Antioxidants

something less reactivesomething less reactive

•• FreeFree‐‐radicals damage membranes, proteins, and DNAradicals damage membranes, proteins, and DNA

•• Vitamins C, E, betaVitamins C, E, beta‐‐carotenecarotene–– Athletes may require increased intake due to exerciseAthletes may require increased intake due to exercise‐‐induced induced increases in freeincreases in free‐‐radical formationradical formation

R l i iR l i i i d d l di d d l d•• Role in exerciseRole in exercise‐‐induced muscle damageinduced muscle damage–– Reactive oxygen species (ROS)Reactive oxygen species (ROS)

–– Inconclusive dataInconclusive data

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•• Possible risks of highPossible risks of high‐‐dose antioxidant dose antioxidant supplementation:supplementation:

Micronutrients as AntioxidantsMicronutrients as Antioxidants

–– In heavy smokers, Vitamin E and betaIn heavy smokers, Vitamin E and beta‐‐carotene may carotene may increase risk for lung cancerincrease risk for lung cancer

–– Other side effects:Other side effects:•• Urinary stone formation (Vitamin C)Urinary stone formation (Vitamin C)

•• Birth defects (Vitamin A)Birth defects (Vitamin A)( )( )

•• Inhibit absorption of other vitaminsInhibit absorption of other vitamins

–– Conclusion:Conclusion:•• Athletes should consume a natural diet that is rich in Athletes should consume a natural diet that is rich in antioxidantsantioxidants

Essential Functions of the MicronutrientsEssential Functions of the Micronutrients

•• Oxygen TransportOxygen Transport–– Iron: Iron: HemeHeme and and myoglobinmyoglobin, , cytochromescytochromes

–– Anemia: Anemia: Can negatively impact performanceCan negatively impact performance

Table 9‐12

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•• Cofactors in enzyme catalyzed reactions:Cofactors in enzyme catalyzed reactions:–– Niacin, pyridoxine, thiamin are involved in Niacin, pyridoxine, thiamin are involved in

b h d b lb h d b l


carbohydrate metabolismcarbohydrate metabolism

–– Riboflavin, thiamin, Riboflavin, thiamin, pantothenicpantothenic acid, and biotin are acid, and biotin are involved in fat metabolisminvolved in fat metabolism

–– Vitamin BVitamin B66 and K are involved in protein metabolismand K are involved in protein metabolism

–– Niacin is a precursor of NAD and NADPNiacin is a precursor of NAD and NADP

–– Riboflavin is a precursor of FAD and FMNRiboflavin is a precursor of FAD and FMN

–– Zinc and magnesium are important for 200 and 300 Zinc and magnesium are important for 200 and 300 enzymes, respectivelyenzymes, respectively

Essential Functions of the Micronutrients micronutrs are WIDELY involved in metabolismEssential Functions of the Micronutrients micronutrs are WIDELY involved in metabolism

Fig 9‐9

u

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•• Micronutrients in immune function and Micronutrients in immune function and resistance to infection:resistance to infection:


resistance to infection:resistance to infection:––BB1212 and folic acid are needed for the normal and folic acid are needed for the normal production of white blood cellsproduction of white blood cells

––A,C and E are needed for normal immune A,C and E are needed for normal immune functionfunction

–– Zinc, iron, copper, and selenium are essential Zinc, iron, copper, and selenium are essential for optimal immune functionfor optimal immune function

•• Electrolytes in body fluidsElectrolytes in body fluids–– Conduct an electrical current when dissolved in waterConduct an electrical current when dissolved in water–– Major electrolytes:Major electrolytes:


Major electrolytes:Major electrolytes:•• Sodium, potassium, chloride, bicarbonate, phosphate, sulfate, Sodium, potassium, chloride, bicarbonate, phosphate, sulfate, magnesium, calciummagnesium, calcium

–– Major functions:Major functions:•• Na and K = nerve signal transductionNa and K = nerve signal transduction•• Fluid Fluid balance (where Na goes, so follows water)balance (where Na goes, so follows water)

•• Other tissue functionsOther tissue functions–– Calcium = muscle contraction and energy metabolismCalcium = muscle contraction and energy metabolism–– Calcium and Vitamin K = blood clottingCalcium and Vitamin K = blood clotting–– Zinc = appetiteZinc = appetite–– Vitamin A = visionVitamin A = vision–– B complex = synthesis of neurotransmittersB complex = synthesis of neurotransmitters

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Effects of Vitamins on Exercise PerformanceEffects of Vitamins on Exercise Performance

•• Older research reported an Older research reported an ergogenicergogeniceffect of vitamins on performance:effect of vitamins on performance:effect of vitamins on performance:effect of vitamins on performance:––Many of these studies were poorly Many of these studies were poorly controlledcontrolled

•• More recent research has shown no More recent research has shown no ergogenicergogenic effect on performance if effect on performance if dietary intake was adequatedietary intake was adequate

•• Phosphates:Phosphates:–– Purported effects:Purported effects:

Ergogenic Effect of Mineral SupplementationErgogenic Effect of Mineral Supplementation

•• Increase ATP synthesisIncrease ATP synthesis

•• Improve oxygen extraction by muscle (2,3Improve oxygen extraction by muscle (2,3‐‐DGP)DGP)

–– Experimental evidence is lackingExperimental evidence is lacking

•• BicarbonateBicarbonate–– Improve buffering of lactic acidImprove buffering of lactic acidImprove buffering of lactic acidImprove buffering of lactic acid

–– Amount needed for effect often leads to severe GI Amount needed for effect often leads to severe GI distressdistress

–– Can lead to inadequate absorption of carbohydrates Can lead to inadequate absorption of carbohydrates and other essential micronutrientsand other essential micronutrients

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Recommendations for Micronutrient Intake in AthletesRecommendations for Micronutrient Intake in Athletes

•• In general, supplementation of vitamins and antioxidants is not In general, supplementation of vitamins and antioxidants is not recommended and may do more harm than goodrecommended and may do more harm than good

•• Dietary intake should be adequate for most athletes with a Dietary intake should be adequate for most athletes with a proper dietproper dietproper dietproper diet

•• However, some athletes at risk (esp. w/ energyHowever, some athletes at risk (esp. w/ energy‐‐restricted diet)restricted diet)–– Recommendations for calcium:Recommendations for calcium:

•• 3 servings/day of low3 servings/day of low‐‐fat dairy foodsfat dairy foods•• Include these dairy foods in highInclude these dairy foods in high‐‐CHO mealsCHO meals•• Eat fish with bones (i.e. sardines)Eat fish with bones (i.e. sardines)•• Include calciumInclude calcium‐‐enriched soy productsenriched soy productsE t l f t blE t l f t bl•• Eat leafy green vegetablesEat leafy green vegetables

–– Iron intake:Iron intake:•• Eat foods rich in Eat foods rich in iron iron at least 4x/weekat least 4x/week•• Eat iron fortified foodsEat iron fortified foods•• Include nonInclude non‐‐hemeheme iron food sourcesiron food sources•• Combine nonCombine non‐‐hemeheme sources with Vitamin C rich foodssources with Vitamin C rich foods•• Avoid caffeine (tea, coffee) with mealsAvoid caffeine (tea, coffee) with meals

•• AmenorrheicAmenorrheic female athletes:female athletes:–– Calcium supplementsCalcium supplements

Recommendations for Micronutrient Intake in AthletesRecommendations for Micronutrient Intake in Athletes

•• Athletes who train and compete in hot Athletes who train and compete in hot environments:environments:–– Increase iron, zinc, magnesiumIncrease iron, zinc, magnesium

–– Should not exceed 1 to 2x the RDAShould not exceed 1 to 2x the RDA

Increased needs are due to sweat lossesIncreased needs are due to sweat losses–– Increased needs are due to sweat lossesIncreased needs are due to sweat losses

•• Overall, a healthy, balanced, calorically proper Overall, a healthy, balanced, calorically proper diet should provide the appropriate vitamins diet should provide the appropriate vitamins and minerals for most all athletesand minerals for most all athletes

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