Vitamin B3
Where to Find It
The best food sources of vitamin B3 are peanuts, brewer’s yeast, fish, and meat. Some vitamin B3 is also found in whole grains.
Best Form to Take
Vitamin B3 occurs naturally in two forms: niacin (or nicotinic acid) and niacinamide (or nicotinamide). There are important differences between the forms when it comes to effectiveness and side effects. In very large doses (more than 3 grams a day), both forms may cause reversible hepatotoxicity (liver damage). However, niacinamide does not appear to have the other side effects associated with niacin, such as skin flushing, itching, and urticaria. Time-release niacin may reduce the risk of skin flushing, but such preparations raise even greater concerns about hepatotoxicity. Niacin improves serum lipid levels, whereas niacinamide does not. Niacinamide is used more often than niacin for conditions that respond to vitamin B3, because of its lower toxicity profile.8
How to Use It
In part because it is added to white flour, most people generally get enough vitamin B3 from their diets to prevent a deficiency. However, 10–25 mg of the vitamin can be taken as part of a B-complex or multivitamin supplement. Larger amounts are used for the treatment of various health conditions.