Nutrition II

1. Nutrition II Micronutrients and Water

2. Vitamins • Organic substances • Classification of Vitamins • Fat soluble: A, D, E, K • Water soluble: C, B complex • Require a daily supply • Are water soluble vitamins potentially harmful when taken in excess?

3. Antioxidant Role of Vitamins • Chemical reactions often result in formation intermediate products. • Reactive intermediates are highly unstable. • A free radical is a highly reactive intermediate species that has an unpaired electron. A free radical might look like this.

4. Antioxidant Role of Vitamins • Buildup of free radicals creates oxidative stress that increase potential for cellular damage. • Oxidative damage, another name for the chemical reaction that free radicals cause, can lead to a breakdown or even hardening of lipids, which makeup all cell walls. • If the cell wall is hardened (lipid peroxidation) then it becomes impossible for the cell to properly get its nutrients, get signals from other cells to perform an action (such as firing of a neuron) and many other cellular activities can be affected. In addition to the cell walls, other biological molecules are also susceptible to damage, including RNA, DNA and protein enzymes.

5. Antioxidant Role of Specific Vitamins To combat the free radical chain propagation effect, the body uses antioxidants (chemical electron sinks) which quench the biochemical fire. The antioxidants include enzymes such as glutathione peroxidase, catalase and superoxide dismutase. Vitamin C, vitamin E, and A, beta carotene , coenzyme Q10, grape seed extract and others are potent antioxidants.

6. Megadoses of Vitamins • Does not improve exercise performance or potential to sustain intense physical training • Can be toxic at high doses • Excess C  increase uric acid • B6  liver & nerve damage • Niacin  inhibit FA mobilization • Folic acid  allergic response SuperHealthPills

7. Vitamin Supplementation? • Not necessary if diet is healthy • Multivitamins are safe (100% RDA) • Benefits those with marginal intake • Supplementation above the RDA may be toxic and 40 years of research does NOT support ergogenic benefit.

8. Minerals • Inorganic elements • Two types • Major (macrominerals) > 100 mg/day • Trace (microminerals) < 100 mg/day • Major functions • Provide structure in forming bones • Maintain normal heart rhythm, nerve conduction, muscle contractility • Help regulate cellular metabolism

9. Calcium • Bone & teeth formation, muscle action, blood clotting, nerve impulse transmission • Important for preventing osteoporosis • RDI adults = 1200 mg/day • Found in dairy products and vegetablesHigh protein diets leach calcium from bones and promote osteoporosis

10. Calcium • Lack of calcium contributes to osteoporosis • Female athlete triad • Disordered eating • Osteoporosis • Amenorrhea

11. Sodium, Potassium, Chloride • What is an electrolyte? • A mineral that when dissolved in the body becomes an ionic conductor • Recommended daily intake of sodium • In mg • In teaspoons of table salt • What are negative effects of excess sodium intake?

12. Iron • Important component of hemoglobin • Dietary sources of iron: eggs, lean meats, legumes, whole grains • Inhibitors of iron absorption: phytic acid (whole grains) & polyphenols (tea, coffee, other beverages) • Iron deficiency is known as anemia(Symptoms: shortness of breath, fatigue)

13. Water • Water in body in 2 compartments • Intracellular 65% • Extracellular 35% • Much of fluid lost through sweating comes from extracellular, primarily blood plasma.

14. Water • Without water, death occurs within days • Body’s transport and reactive medium • Absorption of heat with minimal changes in body temperature • Watery fluids lubricate • Provides structure and form to body through turgor

15. Water • Sedentary adult in thermoneutral environment requires about 2.5 L of water daily. • Liquid – 1200 ml • Food – 1000 ml • Metabolism – 350ml • Water output (no exercise) • Urine – 1250 ml • Skin – 850 ml • Expiration – 350 ml • Feces – 100 ml • Water output exercise*

16. Water, Glucose, and Electrolytes • Consume 400 to 600 mL of fluid immediately before exercise, subsequent ingestion 250 mL @ 15 min • To optimize water & carbohydrate absorption • fluid temperature and volume • use a 6% carbohydrate electrolyte solution. • Adding sodium to rehydration beverage maintains plasma osmolarity. • What is hyponatremia?