Niacin
An essential B vitamin (B3) added to foods and supplements to support energy metabolism; most commonly present as nicotinic acid or niacinamide (nicotinamide).
Should I eat Niacin?
Niacin is an essential vitamin added in small amounts to prevent deficiency and support energy metabolism. It is safe for most people at label levels, but combining multiple fortified foods and supplements can exceed the UL and cause flushing, especially with nicotinic acid.
Summary
Niacin refers to nicotinic acid and niacinamide, both of which your body uses to make NAD/NADP for energy and cell function. The Daily Value is 16 mg niacin equivalents, and fortification is a long‑standing, effective public‑health practice. FDA affirms niacin and niacinamide as GRAS when used under good manufacturing practice. The main side effect is flushing with nicotinic acid at higher supplemental intakes; very high medical doses can affect the liver or glucose handling. For most people, typical amounts in fortified foods are safe and helpful, provided total intake from all sources stays within recommended limits.
Key Research Points
Flushing risk depends on form and dose
Nicotinic acid can trigger skin flushing at supplemental doses; the U.S. UL is 35 mg/day to limit this, while the EU sets 10 mg/day specifically for nicotinic acid. Niacinamide (nicotinamide) rarely causes flushing.
Very high doses need medical oversight
Pharmacologic intakes (about 1–3 g/day) used for lipid management can raise liver enzymes and may impair glucose tolerance; these effects are not expected at typical fortification levels.
Watch label stacking and niacin equivalents
The Daily Value is 16 mg niacin equivalents (NE), which count both preformed niacin and tryptophan from protein. Combining several fortified foods plus a multivitamin can exceed the UL and trigger flushing, especially with nicotinic acid.
Overview
What is it?
Why is it used?
Origin
Modern niacin fortification traces back to pellagra prevention efforts in the early–mid 20th century, when public health programs began enriching flour and cereals. Today, industry mainly uses synthesized nicotinic acid or niacinamide produced from pyridine intermediates; both convert to NAD/NADP in the body, the coenzymes central to energy production.
Process: Oxidize pyridine intermediates; refine and crystallize
Steps
Chemicals
Research & Safety
Potential Concerns
The most common side effect is flushing from nicotinic acid at supplemental doses; the U.S. UL of 35 mg/day and the EU UL of 10 mg/day for nicotinic acid are set to minimize this. Niacinamide (nicotinamide) rarely causes flushing at nutritional doses. Very high intakes used as medicine (around 1–3 g/day) can raise liver enzymes and may worsen glucose tolerance; these intakes require medical supervision and are far above amounts in typical fortified foods. Stacking several fortified products with a multivitamin can exceed the UL and trigger flushing, so check labels and consider total daily intake.
Potential Benefits
Niacin is essential for making NAD and NADP, which help your cells turn carbohydrates, fats, and protein into usable energy. Fortified foods help most adults reach the 16 mg NE Daily Value and lower the risk of deficiency. Historically, enrichment of grain products cut rates of pellagra, the classic niacin deficiency disease. Your body can convert tryptophan (an amino acid in protein) into niacin, but this is limited, so reliable dietary niacin still matters.
Digestive Effects
At higher supplemental intakes, some people feel warmth, itching, or redness of the skin (flushing) with nicotinic acid; this is uncomfortable but usually short‑lived. Nausea or mild stomach upset can occur in some users at supplemental doses. Niacinamide generally causes fewer sensory effects than nicotinic acid at comparable doses. Typical fortification levels in foods (often around 10–20 mg per serving) are below levels that commonly cause symptoms in most people.
Limit Consumption
Infants have no established UL; their needs should be met by breast milk, formula, and age‑appropriate foods rather than supplements. People with liver disease, gout, peptic ulcers, or diabetes are more likely to have problems at high supplemental doses and should avoid medical‑dose niacin without clinician guidance. Because different forms behave differently, those sensitive to flushing may tolerate niacinamide better than nicotinic acid at nutritional intakes. Be mindful that combining multiple fortified products with a multivitamin can exceed the UL and provoke flushing.
Fact Sheet
Regulatory Status
ESG & Sustainability
Allergens and Diet
Natural Alternatives
Sunflower seeds
Peanuts
Tuna
Citations
Niacin – Health Professional Fact Sheet
2024-07-12NIH ODS • NIH Office of Dietary Supplements
Daily Value on the Nutrition and Supplement Facts Labels
2024-03-05U.S. FDA • U.S. Food and Drug Administration
Scientific Opinion on Dietary Reference Values for niacin
2014-01-01EFSA NDA Panel • EFSA Journal
21 CFR §184.1530 – Niacin
2023-03-24U.S. FDA • Code of Federal Regulations
21 CFR §184.1535 – Niacinamide
2023-03-24U.S. FDA • Code of Federal Regulations
Methods to Produce Nicotinic Acid with Potential Industrial Applicability
2022-02-10Lisicki D., et al. • ACS Catalysis (Open via PMC)
Class Names and the International Numbering System for Food Additives (CXG 36-1989)
2025-07-01FAO/WHO Codex • Codex Alimentarius
Converting Units of Measure for Folate, Niacin, and Vitamin A
2019-08-09U.S. FDA • U.S. Food and Drug Administration