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Vitamins & Minerals

Learn the importance of vitamins and minerals for physiological functions, vitamin categories, exercise requirements, antioxidants, free radicals, and mineral functions. Discover recommended intakes and factors affecting absorption.

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Vitamins & Minerals

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  1. Vitamins & Minerals Chapter 9

  2. Vitamins • Organic compounds that are essential for the optimal functioning of many different physiological processes in the body • Major Functions • Coenzymes • Hormones • Neurotransmitters • Antioxidants

  3. Vitamin Categories • Water Soluble • Vitamin C • B-Vitamins (thiamin, riboflavin, niacin, B6, B12, folic acid, pantothenic acid, biotin) • Fat Soluble • Vitamin A (Retinol or beta carotene) • Vitamin D (calciferol) • Vitamin E (-tocopherol) • Vitamin K (menaquinone)

  4. Exercise and Vitamin Requirements • Inadequate vitamin status impairs performance • Dies exercise increase vitamin requirement • Decreased absorption? • Loss in sweat? • Increased mitochondrial density? • Muscle hypertrophy? • Anti-oxidant requirement?

  5. Athletes at Risk • Low energy intake • Females • Gymnasts, dancers, wrestlers • Unbalanced diet

  6. Vitamin Supplementation Above the DRI or RDA • Vitamin B6 may improve aerobic power • Vitamin C may enhance heat acclimatization • Vitamin E may enhance aerobic power at altitude • B-complex vitamins may increase short term performance/recovery in hot climates

  7. Antioxidants & Free Radicals • Oxygen Free Radicals • Molecules with an unpaired electron in their outer orbit • Produced by the reduction of molecular oxygen, and ongoing process during normal cellular respiration • Examples are superoxide (O2-), hydrogen peroxide (H2O2), and hydroxyl radical (OH-) • Between 2-5% of the total electron flux during normal metabolism generate free radicals

  8. Consequences of Free Radicals • Deterioration of membrane lipids • Changes in membrane protein structure • Mitochondria appear to be most susceptible to free radical damage • Free radical damage has been implicated in diseases such as heart disease, cancer, diabetes, immune dysfunction, accelerated aging

  9. Exercise and Free Radicals • Increase in cellular respiration increases FR production • Increase in body temperature increases rate of FR formation • Increase in catecholamines increases FR formation

  10. Natural Defenses Against Free Radicals • Protective antioxidant enzymes • Exercise training increases the level of antioxidant enzymes but oxidative potential of the muscle increases more • Nutritional antioxidants work with the enzymes • Primary nutritional antioxidant vitamins are C, E, and beta-carotene

  11. Recommended Intake of Antioxidant Vitamins • Beta-Carotene • DRI: 10-11 mg • Recommended: 20 mg • Vitamin C • DRI: 75-90 mg • Recommended: 250 mg • Vitamin E • DRI: 22.5 IU • Recommended: 150 IU

  12. Minerals • Minerals are inorganic solid elements found in nature in plants, animal tissue, and water. • 15 known essential minerals and 5 nonessential composing less than 4% of the body weight

  13. Functions of Minerals • Building blocks for body tissues such as bones, teeth, & muscles • Components of metalloenzymes which regulate metabolism • Exist as ions or electrolytes involved in metabolism & body water regulation • Components of hormones

  14. Classification of Minerals • Macrominerals • RDA or ESADDI is > 100 mg per day or body contains more than 5 grams • Calcium, phosphorus, magnesium, potassium, sodium chloride, sulfur • Trace Minerals • Needed in quantities < 100 mg • Iron, copper, chromium, selenium, boron, vanadium, cobalt, fluoride, iodine, manganese, molybdenum

  15. Calcium • Major Functions • Bone formation • Enzyme activation • Nerve impulse transmission • Muscle contraction • Cell membrane potentials

  16. Current DRIs for Calcium • Ages 9-18 • Males: 1300 mg • Females: 1300 mg • Ages 19-50 • Males: 1000 mg • Females: 1000 mg

  17. Factors Altering Ca Absorption/Utilization • Dairy sources absorbed better than plant • Vitamin D and lactose increase • Phytates in plants decrease • Fiber decreases • Excessive protein decreases • Excessive coffee decreases • Excessive alcohol decreases

  18. Consequences of Low Ca • Low serum calcium is rare because of the ability to absorb Ca from bones • Muscular cramping • Impaired muscular contraction • Colon Cancer • Osteoporosis

  19. Consequences of Too Much Ca • Abnormal heart rhythms • Kidney stones • Reduces iron and zinc absorption

  20. Calcium Supplements • Calcium citrate, carbonate, lactate, gluconate, antacids • Citrate is the best for absorption • Taken with meal is best • Taken in 200-300 mg doses is best

  21. Female Athlete Triad • Disordered eating • Secondary amenorrhea due to hormonal deficits and imbalances • Osteoporosis

  22. Iron • Major Functions • Used to form hemoglobin, cytochromes, and Kreb-cycle metalloenzymes • 70% is activety used • 30% is stored as ferritin • As many as 90% of females get less than RDA but body partly compensates by increasing absorption • 16% of females have iron-deficiency anemia

  23. RDA for Iron • Ages 9-13 yr • Males: 8 mg • Females: 8 mg • Ages 14-18 yr • Males: 11 mg • Females: 15 mg • Ages 19-50 yr • Males: 8 mg • Females: 18 mg

  24. Types of Iron • Heme iron • Animal sources • Best absorption: 10-30% • Animal sources are 40% heme, 60% non-heme • Non-heme iron • Plant sources • Poorly absorbed: 2-10%

  25. Factors Affecting Iron Absorption • Increases absorption • Vitamin C for non-heme iron • MPF for both heme and non-heme • Decreases absorption • Tannins in tea (by 60%) • Phytic acid in whole grains • Oxalic acid in green leafy vegetables • Calcium for non-heme

  26. Sources of Iron • Animal • 4 oz liver- 10 mg • 4 oz beef, pork, dark poultry – 5-6 mg • 4 oz white poultry – 1 mg • Plant • 8 oz prune juice – 3 mg • 1/3 cup dates, raisins, prunes – 1 mg • ½ cup spinach, beans, broccoli – 2 mg

  27. Iron Deficiency • Stage 1 • Depletion of bone marrow stores and decrease in serum ferritin • Stage 2 • Further decrease in serum ferritin and loss on some Hb, but Hb still normal • 30-50% of female and 15-30% of male distance runners are in this stage • Stage 3 (iron-deficiency anemia) • Very low serum ferritin and low Hb • < 13 grams Hb for males • < 11 grams Hb for females

  28. Sports Anemia • Low Hb levels due to expanded blood volume • Iron stores are normal

  29. Iron Supplementation and Performance • Iron supplementation will improve performance in iron-deficiency anemia • Iron supplementation will improve iron status in iron deficiency (stage 2) without anemia but may not improve performance • Iron supplementation will not improve performance when iron stores are normal

  30. Sodium or Natrium (Na+) • Functions • Primary electolyte in extracellular fluid • Fluid balance and osmotic pressure • Nerve conduction and muscle contraction

  31. Recommended Na+ Intake • No RDA • Minimal requirement is 500 mg • Salt is 40% sodium • Most recommendation is < 3000 mg/day

  32. Effects of High N+ Intakes • Associated with high BP in ~ 20% of population • Water retention

  33. Effects of Low Na+ Intakes • Muscle cramps???? • Disruption of cardiac electrical activity which can result in death

  34. Sources Containing 300 mg Ca • 8 oz of milk • 1.5 oz of cheese • 1 cup yogurt • 1.75 cups ice cream • 8 oz fortified OJ • 1 serving fortified cereal

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