Niacin (vitamin B3)
What it is and what it does
- Niacin (vitamin B3) is one of the water-soluble B vitamins. (NIH Office of Dietary Supplements. Niacin Fact Sheet for Health Professionals (updated 2022-11-18))
- The body can also make niacin from tryptophan, an amino acid in protein. (NIH Office of Dietary Supplements. Niacin Fact Sheet for Consumers (updated 2021-03-22))
- Niacin helps turn food into energy. (NIH Office of Dietary Supplements. Niacin Fact Sheet for Consumers (updated 2021-03-22))
- Niacin's active form, NAD, is used by more than 400 enzymes, more than any other vitamin-derived coenzyme. (NIH Office of Dietary Supplements. Niacin Fact Sheet for Health Professionals (updated 2022-11-18))
- NAD transfers energy from carbohydrates, fats and proteins to ATP, the cell's energy currency. (NIH Office of Dietary Supplements. Niacin Fact Sheet for Health Professionals (updated 2022-11-18))
- NADP, another active form, is used to build cholesterol and fatty acids. (NIH Office of Dietary Supplements. Niacin Fact Sheet for Health Professionals (updated 2022-11-18))
Why it matters
- Severe niacin deficiency causes pellagra. (NIH Office of Dietary Supplements. Niacin Fact Sheet for Consumers (updated 2021-03-22))
- Pellagra causes a pigmented rash or brown discolouration on skin exposed to sunlight, among other effects. (NIH Office of Dietary Supplements. Niacin Fact Sheet for Health Professionals (updated 2022-11-18))
- Diets low in iron, riboflavin or vitamin B6 limit the conversion of tryptophan to niacin. (NIH Office of Dietary Supplements. Niacin Fact Sheet for Consumers (updated 2021-03-22))
- Indian diet surveys show average niacin intake of about 10 mg a day. (ICMR-NIN Expert Group. Short Report of Nutrient Requirements for Indians: Recommended Dietary Allowances and Estimated Average Requirements - 2020)
- Too much: niacin naturally in food is safe; supplements with 30 mg or more of nicotinic acid can cause skin flushing. (NIH Office of Dietary Supplements. Niacin Fact Sheet for Consumers (updated 2021-03-22))
General information, not medical advice — for your own needs, ask a doctor or dietitian.
How much is needed
| Who | Amount | What the figure is | Whose figure |
|---|---|---|---|
| Adult man, sedentary work | 14 mg/day | recommended dietary allowance | ICMR-NIN 2020 |
| Adult woman, sedentary work | 11 mg/day | recommended dietary allowance | ICMR-NIN 2020 |
| Pregnant woman | +2 (added to the non-pregnant value) mg/day | recommended dietary allowance | ICMR-NIN 2020 |
| Adult men and women (and pregnancy where stated) | 35 mg/day | safe upper limit | ICMR-NIN 2020 |
Sources: ICMR-NIN Nutrient Requirements for Indians 2020, as given by FSSAI (Direction of 2 Aug 2021); ICMR-NIN Nutrient Requirements for Indians 2020 (Short Report)
In every millet and pseudo-cereal, per 100 g raw
| Grain | Amount | Source |
|---|---|---|
| Niacin (B3) | ||
| Kuttu (buckwheat) | 7.02 mg | USDA FDC 170286 |
| Proso millet | 4.72 mg | USDA FDC 169702 |
| Barnyard millet | 4.2 mg | NIN 2007 via ICAR-IIMR |
| Teff | 3.363 mg | USDA FDC 169747 |
| Foxtail millet | 3.2 mg | NIN 2007 via ICAR-IIMR |
| Jowar (sorghum) | 2.1 mg | IFCT A005 |
| Quinoa | 1.7 mg | IFCT A009 |
| Fonio | 1.6 mg | FAO WAFCT 2019 |
| Kodo millet | 1.49 mg | IFCT A017 |
| Ragi (finger millet) | 1.34 mg | IFCT A010 |
| Little millet | 1.29 mg | IFCT A016 |
| Bajra (pearl millet) | 0.86 mg | IFCT A003 |
| Rajgira (amaranth) | 0.52 mg | IFCT A002 |
| Niacin equivalents | ||
| Fonio | 3.3 mg | FAO WAFCT 2019 |
Each grain has ONE source, named on its page: IFCT = Indian Food Composition Tables 2017 (ICMR-NIN) with its food code; USDA FDC; FAO WAFCT 2019; NIN 2007 via ICAR-IIMR. Values exactly as printed, not converted — tables differ in method, so compare within a source. Published values for the grain, not a laboratory test of our packs.
Absorption and food
- Because the body converts some tryptophan to NAD, tryptophan counts as a dietary source of niacin. (NIH Office of Dietary Supplements. Niacin Fact Sheet for Health Professionals (updated 2022-11-18))
- US values use 'niacin equivalents' (mg NE) to count both niacin and niacin made from tryptophan. The ICMR table prints niacin as mg/d. (NIH Office of Dietary Supplements. Niacin Fact Sheet for Consumers (updated 2021-03-22))
- B-complex vitamins (and vitamin C) are sensitive to heat and air, so drying, cooking and processing can reduce them. (ICMR-NIN. Dietary Guidelines for Indians 2024)