Recommended Daily Niacin Intake for Adults
Adults need 14-16 mg of niacin (vitamin B3) per day from all sources, including food and supplements. The Recommended Dietary Allowance (RDA) is 16 mg for men aged 19+ and 14 mg for women aged 19+, measured as niacin equivalents (NE) to account for conversion from tryptophan in protein-rich foods.[1]
Women who are pregnant require 18 mg NE daily, and those breastfeeding need 17 mg NE.[1]
How Niacin Requirements Differ by Age and Sex
Requirements stay consistent for adults up to age 70, then rise slightly to 15 mg NE for women and 16 mg NE for men over 70, due to potential absorption changes with age.[1]
Young adults (19-30) match these levels, with no major sex-based differences beyond the baseline split.
Upper Limits to Avoid Side Effects
The tolerable upper intake level (UL) is 35 mg NE per day from supplements or fortified foods for adults. Exceeding this risks flushing, itching, or liver issues. Natural food sources don't count toward the UL.[1]
Food Sources Meeting Daily Needs
A serving of chicken breast (3 oz) provides about 12 mg NE, tuna (3 oz) around 10 mg, or peanuts (1 oz) 4 mg. Most people meet needs through diet without supplements.[1]
Sources
[1]: NIH Office of Dietary Supplements - Niacin Fact Sheet