What niacin does
Vitamin B3 is part of NAD, a coenzyme involved in hundreds of reactions that release energy from food and repair DNA.
How much
Adults need about 14–16 mg a day. Your body can also make some niacin from the amino acid tryptophan.
Plant sources
Peanuts and peanut butter, mushrooms, brown rice, whole grains, peas, legumes and nutritional yeast.
How many portions of each food would cover a day's niacin?
A note
High-dose niacin supplements can cause flushing and, long-term, liver problems. Food sources are safe.