Cover Image


View/Hide Left Panel

Risk Characterization

Niacin intake data indicate that a small percentage of the U.S. population is likely to exceed the UL. Individuals who take over-the-counter niacin to treat themselves, for example, for high blood cholesterol, might exceed the UL on a chronic basis. The UL is not meant to apply to individuals who are receiving niacin under medical supervision.


Data useful for setting the Estimated Average Requirement (EAR) for children, adolescents, pregnant women, and lactating women are scanty, but evidence suggests that niacin intake in the United States and Canada is generous relative to need. Priority should be given to studies in two areas:

  • the niacin requirement to satisfy nicotinamide adenine dinucleotide (NAD) needs for increased adenosine diphosphate ribosylation resulting from oxidant-deoxyribonucleic acid damage and

  • sensitive and specific blood measures of niacin status. Current assessments of niacin status and requirement are based solely on urinary metabolite measures; measurements of plasma metabolites such as the 2-pyridone derivatives may be productive. Two recent experimental studies have suggested erythrocyte NAD as a functional blood measure of niacin status (Eu et al., 1989; Ribaya-Mercado et al., 1997), but further work is needed in clinical populations.


Bean WB, Spies TD. 1940. A study of the effects of nicotinic acid and related pyridine and pyrazine compounds on the temperature of the skin of human beings. Am Heart J 20:62–75.

Bechgaard H, Jespersen S. 1977. GI absorption of niacin in humans. J Pharm Sci 66:871–872.

Bernofsky C. 1980. Physiology aspects of pyridine nucleotide regulation in mammals. Mol Cell Biochem 33:135–143.

Carpenter KJ, Lewin WJ. 1985. A reexamination of the composition of diets associated with pellagra. J Nutr 115:543–552.

Carter EG, Carpenter KJ. 1982. The bioavailability for humans of bound niacin from wheat bran. Am J Clin Nutr 36:855–861.

CDC (Centers for Disease Control and Prevention). 1983. Niacin intoxication from pumpernickel bagels—New York. MMWR 32:305.

Clementz GL, Holmes AW. 1987. Nicotinic acid-induced fulminant hepatic failure. J Clin Gastroenterol 9:582–584.

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement