Niacin is one of the most-used vitamins in your body and one of the few B vitamins with a well-known side effect. Here's what to know.
Written by Vita Globe Editorial Team | Reviewed against NIH Office of Dietary Supplements guidance | Updated October 7, 2026
Quick Answer
Niacin (vitamin B3) becomes NAD and NADP, which your cells use in more than 400 reactions, mostly to release energy from food[1]. Adults need 16mg a day (men) or 14mg (women). The upper limit from supplements is 35mg a day. The nicotinic acid form can cause skin flushing at about 30 to 50mg, while niacinamide does not[1].
In this article
What does niacin do?
Your body converts niacin into NAD, which is used in more than 400 enzyme reactions, more than any other vitamin-derived coenzyme. Most of those reactions help turn carbohydrates, fats and protein into energy. NADP, its cousin, helps build fats and cholesterol and protects cells from oxidative stress[1].
How much niacin do you need?
- Adult men: 16mg NE a day
- Adult women: 14mg NE a day
- Upper limit from supplements: 35mg a day for adults[1]
"NE" means niacin equivalents. Your body can also make some niacin from tryptophan, an amino acid in protein foods[1].
Niacin vs. niacinamide: what's the difference?
- Nicotinic acid is the form that causes "niacin flush": warm, red, itchy skin that usually fades within an hour. It's also used at very high doses under medical supervision[1].
- Niacinamide (nicotinamide) provides the same vitamin activity but does not cause flushing[1]. It's the form in our B Complex gummies.
High-dose nicotinic acid can also raise blood sugar, so people on diabetes medications should only use it with medical guidance[1].
Which foods have niacin?
Poultry, beef, pork, fish such as tuna and salmon, brown rice, peanuts and fortified cereals and breads are good sources. Most people in the U.S. get enough niacin from food[1].
Our option
Vita Globe Vitamin B Complex Gummies
12mg of niacin as flush-free niacinamide per gummy (75% DV), alongside five other B vitamins.
Frequently asked questions
Is niacin flush dangerous?
It's uncomfortable but usually harmless and short-lived. It happens with nicotinic acid, not niacinamide.
Should I take niacin for cholesterol?
Only under a doctor's care. Cholesterol-lowering doses are far above the upper limit and need monitoring.
Is niacinamide good for skin?
Niacinamide is a popular topical skincare ingredient. That's a separate use from taking it as a vitamin.
Sources
- NIH ODS. Niacin Fact Sheet for Health Professionals. ods.od.nih.gov
About the Vita Globe Editorial Team
The Vita Globe Editorial Team researches and writes our wellness content from peer-reviewed research and guidance from bodies such as the NIH and FDA. We cite sources inline and update articles when the evidence changes.
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. This article is for informational purposes only and is not a substitute for medical advice. Talk to your healthcare provider before starting any new supplement, particularly if you are pregnant, nursing, taking medication, or managing a health condition.
