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1992-12-06
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Niacin
U.S. Recommended Daily Allowances
Infants Children Adults and Pregnant or
(0-12 mo.) (1-3 years) Children 4 Years + Nursiing Women
8 mg 9 mg 20 mg 20 mg
(The U.S. RDA amounts are sufficient to meet the needs
of practically all healthy people.)
Niacin (nicotinic acid, nicotinamide) is a
water-soluble vitamin whose requirement is partly met by
conversion in the body of the essential amino acid
tryptophan to niacin.
Functions: Involved in carbohydrate, protein and fat
metabolism.
Sources: Enriched cereal-grain products; meat, fish,
poultry, cheese, eggs, and milk because they contain
tryptophan; peanuts; mushrooms; potatoes.
Deficiency: Severe niacin deficiency causes pellagra,
a disease characterized by mouth sores, skin rashes,
diarrhea, and dementia. Deficiency is rarely seen in the
United States, though, because most people have adequate
intakes.
Excess: Large amounts of niacin, when taken in the
nicotinic acid form of the vitamin, act as a drug.
Nicotinic acid is often prescribed as a
cholesterol-lowering drug, and should be taken only under
the supervision of a physician. Side effects include
vascular dilation of the skin (flushing) and
gastrointestinal distress. Prolonged intake may cause liver
damage.
Nicotinamide is not known to act as a drug. Effects of
high doses are unknown.