Niacin, also known as B3, is required for the breakdown of fats, carbohydrates and protein. Dietary sources of niacin include milk, eggs, meats, liver, green vegetables and cereal grains. Breakfast cereals, breads and other enriched foods are fortified with niacin.

Getting too little niacin results in a condition known as pellagra, characterized by “the four D’s”: dermatitis, diarrhea, dementia and death. Pellagra became common in Europe in the 1700s after cultivation of corn became widespread. Corn is actually rather high in niacin but not in a form that is easily absorbed by the body. Early in the 1900s, pellagra was common in the southern U.S. among poor people who ate mainly corn or sorghum. Yet at the same time, it was rare in Mexico, where corn was a dietary staple. Mexicans made tortillas from corn by soaking them in a lime solution. When corn is heated in an alkaline solution, the niacin is released for easier absorption.

Benefits: Niacin is a well-accepted treatment for high cholesterol and is as effective as some prescription drugs. Patients should check with their doctor before taking niacin in high doses, as it can cause other side effects. The non-therapeutic upper limit for safe niacin consumption was set at 3,500 micrograms. Studies suggest that niacin may be useful for treating advanced macular degeneration. Because niacin deficiency causes dementia, researchers are also studying whether niacin levels could play a role in Alzheimer’s disease.

Daily recommended amount:Men: 1,600 microgramsWomen: 1,400 microgramsPregnant women: 1,800 microgramsLactating women: 1,700 microgramsChildren (0-6 months): 200 microgramsChildren (7-12 months): 400 microgramsChildren (1-3): 600 microgramsChildren (4-8): 800 microgramsChildren (9-13): 1,200 microgramsGirls (14-18): 1,400 microgramsBoys (14-18): 1,600 micrograms

Good sources:Chicken (white meat, 3 oz.): 730 microgramsBeef (lean, 3 oz.): 310 microgramsCereal (fortified, 1 cup): 2,000–2,700 microgramsTuna (canned light, 3 oz.): 1,130 microgramsPeanuts (dry roasted, 1 oz.): 380 micrograms

— Markian Hawryluk, The Bulletin

Sources: National Institutes of Health, Linus Pauling Institute