Water soluble vitamins, Vitamin C and the B Vitamins, are absorbed directly into the bloodstream and travel freely. For the most part, these vitamins are not stored in tissues to a great extent and excesses are excreted from the body. This also means that these must be ingested each day. While these vitamins seldom reach toxic levels, high amounts in some supplements can cause levels in the body to reach toxicity.
Vitamin C (ascorbic acid): Vitamin C works to maintain connective tissue and assists enzymes in performing their jobs, in particular enzymes involved in formation and maintenance of collagen. Collagen helps heal wounds, mend fractures, and support capillaries, preventing bruises. Immune system cells maintain high levels of Vitamin C as well. Vitamin C promotes iron absorption in the intestines.
A popular belief is that Vitamin C will prevent colds. Studies have shown that taking extra Vitamin C does not actually prevent a cold, although it may shorten its duration and lessen the severity of the symptoms.
Too much Vitamin C can be dangerous for people who have an overload of iron in their system or for those on medications to prevent blood clotting.
DRI: Men 90mg/day; Women 75mg/day
Food sources:½ c red pepper 142mg
½ c orange juice 62mg
½ c strawberries 43mg
½ c sweet potato 20mg
B Vitamins: B Vitamins work together, and as a whole, help the body use fuel from carbohydrates, fat and proteins. Thiamin, Riboflavin, Niacin, Biotin and Pantothenic Acid support energy metabolism in every cell of the body.
Thiamin (B1) also aids nerve function.
DRI: Men 1.2mg/day; Women 1.1 mg/day
Food sources:
½ whole wheat bagel .19mg
¾ cup enriched cereal .38mg
1 baked potato .22mg
½ cup green peas .23mg
Riboflavin (B2) also supports normal vision and skin health.
DRI: Men 1.3mg/day; Women 1.1mg/day
Food sources:
1 c milk .45mg
1 c cottage cheese .32mg
½ c spinach .21mg
3 oz pork chop .23mg
Niacin (B3) contributes to skin health and nervous and digestive system function.
DRI: Men 16mg/day; Women 14mg/day
Food sources:
3 oz chicken breast 8.9mg
3 oz tuna 11.3mg
¾ c enriched cereal 5.0mg
1 baked potato 3.3mg
Biotin DRI: 30 micrograms/day
Food sources: Meat, milk, egg yolk, legumes, most vegetables
Pantothenic Acid
DRI: 5mg/day
Food sources: meat, eggs, most vegetables, whole grain cereal products
Folate helps the body make new cells.
DRI: 400 micrograms/day
Food sources:1 c spinach 58 micrograms
½ c avocado 45 micrograms
½ c pinto beans 145 micrograms
Vitamin B12 (cobalamin) helps to convert folate to its active form and helps maintain the sheath around nerve cells.
DRI: 2.4 micrograms/day
Food sources:3 oz sirloin steak 2.0 micrograms
1.5 oz Swiss cheese 1.5 micrograms
1 c cottage cheese 2.0 micrograms
Vitamin B6 (pyridoxine) is needed in protein metabolism and helps convert one amino acid to another.
DRI: 1.3mg/day
Food sources:
1 Banana .66mg
3oz chicken breast .35mg
½ c spinach .22mg
Athletes may need more of some water soluble vitamins than their non-athlete counterparts. Typically, the higher needs are met by the increased number of calories that an athlete already needs to power performance and maintain energy levels, as long as the calories come from a combination whole grains, vegetables, fruits, meat and dairy, and not from an extra bag of chips. There have not been conclusive studies showing that supplementation of the B Vitamins or Vitamin C can actually increase performance.
Next week, we will discuss the fat soluble Vitamins A, D, E, and K.
Sources:
Bonci, L. Sports Nutrition for Coaches. 2009.
Sizer, F. and E. Whitney. Nutrition Concepts and Controversies, 10th ed. 2006.
Skolnik, H. and A. Chernus. Nutrient Timing for Peak Performance. 2010.
