Vitamin B3 (Niacin)
A B vitamin whose high-dose form affects cholesterol — with real cautions.
What it is
Niacin is a B vitamin involved in energy metabolism and DNA repair. In high doses (as nicotinic acid) it has drug-like effects on blood lipids.
How it works
Niacin (B3) supports energy metabolism and DNA repair. In high, drug-like doses (as nicotinic acid) it raises HDL and lowers some blood fats — but that's a pharmacological effect distinct from its role as a vitamin.
What it's been studied for
Used to correct deficiency and, at prescription-level doses, historically to alter cholesterol.
What the evidence shows
As a vitamin, niacin is essential. As a high-dose cholesterol treatment, it does raise HDL and lower some lipids, but large outcome trials were disappointing and side effects are significant — so this use has fallen out of favor and belongs under medical supervision.
Who should consider it
As a vitamin, deficiency is rare. High-dose niacin for cholesterol is a medical decision, not a self-care one, since large trials were disappointing and side effects are significant. Vitamin-level amounts appear in B-complexes.
Amounts commonly studied
Vitamin-level needs are small (14-16 mg). High-dose lipid use is a medical decision, not a self-care one.
How to take it
Vitamin needs are small (14-16 mg). High-dose lipid use should only happen under medical supervision. Nicotinic acid causes flushing; nicotinamide doesn't (and has no lipid effect).
Forms & absorption
Nicotinic acid (causes flushing), nicotinamide (no flushing, no lipid effect), and 'no-flush' forms. Extended-release high-dose niacin has been linked to liver injury.
Food sources
Meat, poultry, fish, peanuts, and whole grains; the body can also make some from the amino acid tryptophan.
Safety & interactions
High-dose niacin causes flushing and can affect the liver, blood sugar, and uric acid — don't self-prescribe high doses. Vitamin-level amounts in a B-complex are safe.
Myths & what it won't do
Myth: high-dose niacin is a safe natural cholesterol fix. Reality: outcome trials were disappointing and it can affect the liver, blood sugar, and uric acid — it belongs under medical care. Myth: 'no-flush' niacin gives the same benefits. Reality: the no-flush form generally lacks the lipid effect.
Common questions
- Should I take niacin for cholesterol?
- Only under medical supervision. High-dose niacin has real side effects and its outcome benefits were disappointing in trials.
- Why does niacin cause flushing?
- Nicotinic acid dilates skin blood vessels, causing a warm, red flush. Nicotinamide doesn't flush but also lacks the lipid effect.
- Is the amount in a B-complex safe?
- Yes — vitamin-level niacin in a B-complex is safe; the concern is with high pharmacological doses.
The amounts listed here are what published research has used — not a prescription or a recommended dose for you. Confirm anything you plan to take with your own healthcare provider, especially if you take medications, are pregnant or nursing, or have a health condition.
Related goals
Research on Vitamin B3 (Niacin)
Recommendations on this page are informed by published research. This is educational information, not medical advice.
- HPS2-THRIVE Collaborative Group; Landray MJ, Haynes R, Hopewell JC, et al. Effects of extended-release niacin with laropiprant in high-risk patients. N Engl J Med. 2014;371(3):203-212. View study →Note: In more than 25,000 high-risk patients already on statins, adding extended-release niacin didn't reduce major vascular events and increased serious side effects.
- AIM-HIGH Investigators; Boden WE, Probstfield JL, Anderson T, et al. Niacin in patients with low HDL cholesterol levels receiving intensive statin therapy. N Engl J Med. 2011;365(24):2255-2267. View study →Note: Adding niacin to statin therapy raised HDL but didn't reduce cardiovascular events; the trial was stopped early.