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.