Thiamin (B1) is necessary for normal
growth, normal carbohydrate metabolism
and normal functioning of the heart,
nerves, and muscles. Thiamin deficiency
results in retarded growth and nerve
disorders, and a condition known as
beriberi. Good sources include pork, fish,
eggs, and whole-grain cereals.
Riboflavin (B2) is required for normal
growth, vigor, healthy skin and mucosa,
and normal eye function. Riboflavin is
found in milk products, green leafy
vegetables, and eggs. Other good sources
of vitamin B2 are the organ meats, heart,
kidney, and liver.
Niacin (B3) is necessary for normal
growth and skin health, normal
functioning of the stomach and intestines,
nervous and circulatory systems, and for
metabolism. The best sources are meat,
liver, poultry, and peanuts.
Pyridoxine (B6) is necessary for fat,
carbohydrate, and protein metabolism,
and is sometimes used to treat nausea in
pregnancy. Sources include liver, yeast,
wheat germ, pork, potatoes, and milk.
Vitamin B6 is usually prescribed with
Isonizid (INH) treatment since INH often
causes a pyridoxine deficiency.
Cyanocobalamin (B12) is necessary
for the health of nervous tissue and assists
in iron metabolism and the maturation
process of red blood cells. B12 is used to
prevent pernicious anemia.
sources are liver and kidneys, milk, eggs,
fish, and cheese.
See Appendix IV for more information on
VITAMIN AND MINERAL SUPPLEMENTS
Vitamin supplements are usually not necessary if a
diet includes a wide variety of foods. Exceptions may
occur in prenatal diets in which iron is low, as well as in
patients who are deficient in a specific vitamin.
Vitamin supplements should be taken only on a
physician or dietitians recommendation.
Vitamin and mineral supplements are being widely
used by physically active people because of all the
performance-enhancing claims made by supplement
manufacturers. It is estimated that 4050 percent of
a t h l e t e s u s e s o m e f o r m o f v i t a m i n / m i n e r a l
supplements. Some doses range from amounts similar
to the Recommended Dietary Allowances (RDA) up to
levels many times the RDA. Supplements are useful
under a variety of conditions, such as if an individual
has an existing vitamin or mineral deficiency;
has poor nutrient intake and/or dietary habits; or
is exposed to extreme environmental conditions,
such as altitude.
Often, laxatives are prescribed in conjunction with
some medical treatments and may cause decreased
absorption of vitamins, loss of minerals and elec- trolytes, or
inhibition of glucose uptake. Therefore, any patient on
laxatives should be carefully monitored, and supplementary
nutritives should be administered as necessary.
Taking a general multivitamin supplement appears
to be without measurable performance enhancing
effects in healthy, well-nourished, physically active
Similarly, no improvements in muscle
strength or endurance have been noted in strength
athletes, such as body builders, who tend to use
megadoses of vitamin and mineral supplements. The
indiscriminate use of high-potency vitamins and
minerals is of growing concern since excessive
amounts of vitamins and/or minerals can be harmful
and may result in nutrient imbalances.
intake of some vitamin and mineral supplements can
result in adverseand possibly toxicside effects.
Water is often called the forgotten nutrient.
Water is needed to replace body fluids lost primarily in
urine and sweat. A person can survive weeks without
food but only days without water. Water makes up 70
percent of body weight and is found in every cell in the
body. It is the medium through which nutrients are
transported from the digestive tract to the cells where
they are needed. Water is also the medium through
which the by-products of cell metabolism are
Water also serves as the medium in which the
chemical processes of life take place. It is normally
taken into the body in beverages, soups, and in the form
of solid foods.
Fluid needs are increased with
sweating, vomiting, diarrhea, high-protein diets, and
in hot environments. An insufficient intake may cause
dehydration, evidenced by loss of weight, increased
body temperature, and dizziness.