Vitamin B3 (Niacin)

Yes. Isoniazid and pyrazinamide (TB drugs) interrupt niacin production from tryptophan and can cause pellagra. Large doses of nicotinic acid can raise blood glucose; doses of 1.5 g/day or more are most likely to do so, so people on antidiabetes medications taking high-dose nicotinic acid should have blood glucose monitored. — per the NIH Office of Dietary Supplements; general information, not medical advice.

The cheapest vitamin b3 (niacin) we track works out to $0.03 , against a typical $0.13 across the 90 we can price per dose — about $1.00 a month at the cheapest. That is real from live Amazon US prices, not the sticker price. The full ranking is on the Best Vitamin B3 (Niacin) page.

Piping Rock Niacin Supplement 100mg | 300 | Vitamin B3 for Men and Women… at $0.03 — the lowest cost-per-dose vitamin b3 (niacin) in our catalog. See the full ranking on the Best Vitamin B3 (Niacin) page.

We're tracking 134 active Vitamin B3 (Niacin) deals across Amazon US and partner retailers, ranked by community votes and cost-per-dose — not paid placement.

Across the 90 Vitamin B3 (Niacin) deals we can price per dose (combination products are left out — their single label dose belongs to whichever ingredient the product is built around) the median cost-per-dose is $0.131; the cheapest quartile comes in under $0.073 . Anything below the median is a solid deal for the same molecule.

Deals are submitted by the community and ranked by net votes (hot minus cold) plus cost-per-dose normalised across container sizes. We take no affiliate kickbacks for ordering; sponsored slots, when present, are clearly badged.

The is 14–16 mg/day, easily met by diet. Gram-level niacin is used clinically to shift cholesterol but has real side effects (flushing, liver, blood sugar) and should only be taken under medical supervision — not as a self-prescribed dose.

No adverse effects have been reported from the consumption of naturally occurring niacin in foods, but high intakes of nicotinic acid and nicotinamide taken as a supplement or medication can cause adverse effects. Thirty to 50 mg or more of nicotinic acid typically causes flushing—reddening of the skin on the face, arms, and chest with burning, tingling, and itching—which is considered an unpleasant rather than toxic side effect but can be accompanied by more serious signs such as headache, rash, dizziness, and a decrease in blood pressure — per the NIH Office of Dietary Supplements.

Severe niacin deficiency leads to pellagra, characterized by a pigmented rash on sun-exposed skin, a bright red tongue, digestive changes such as vomiting, constipation or diarrhea, and neurological symptoms including depression, apathy, headache, fatigue, and memory loss; as it progresses, anorexia develops and the affected individual eventually dies. Although pellagra is very rare in the United States, groups most likely to have inadequate niacin status include people who are undernourished (due to poverty, anorexia, alcohol use disorder, AIDS, inflammatory bowel disease, or liver cirrhosis), people with inadequate riboflavin, pyridoxine (B6), or iron intakes (which reduce tryptophan-to-niacin conversion), and people with Hartnup disease or carcinoid syndrome — per the NIH Office of Dietary Supplements.

Niacin is present in a wide variety of foods. Many animal-based foods—including poultry, beef, and fish—provide about 5–10 mg niacin in the highly forms of NAD and NADP, while plant-based foods such as nuts, legumes, and grains provide about 2–5 mg per serving, mainly as nicotinic acid; the niacin in some grain products is only about 30% bioavailable. Among the richest listed sources are beef liver (14.9 mg per 3 ounces), chicken breast and turkey breast (about 10 mg per 3 ounces), and salmon and tuna (8.6 mg per 3 ounces), and many U.S. breads, cereals, and infant formulas contain added niacin in its free, highly bioavailable form — per the NIH Office of Dietary Supplements.