What You Need to Know About the B Vitamin, Niacin
Niacin is an essential nutrient. This vitamin helps your nerves, digestive system, and skin function properly. Niacin can also help support macronutrient metabolism. Read on to learn about niacin’s functions, which foods contain niacin, and the benefits and potential risks of taking niacin supplements.
What Is Niacin?
“Niacin is an essential vitamin also known as vitamin B3,” says Hailey Crean, RD, CDE, founder of Hailey Crean Nutrition. Niacin is water-soluble, meaning that your body doesn’t store it, so excess amounts are excreted through your urine. Water-soluble vitamins need to be consumed regularly (from food or supplements).
“Niacin deficiency in the typical American diet is rare,” says Crean. “However, individuals at risk for niacin deficiency may include those with alcohol abuse, anorexia, malnutrition, inflammatory bowel disease, and cirrhosis.”
What Is the Function of Niacin?
“Niacin is required to activate hundreds of enzymatic reactions throughout the body,” says Crean. “It specifically plays an important role in the reaction that converts nutrients (carbohydrate, fat, and protein) into energy.”
What Foods Contain Niacin?
Niacin “is widely present in the diet,” says Crean. Foods containing the highest amounts of niacin include chicken, turkey, and beef liver. “Brown rice, peanuts, and fortified breakfast cereals are also good vegetarian sources,” she adds. “If needed, tryptophan, an amino acid, can also be converted in the body to niacin.”
The Recommended Dietary Allowance (the average daily dietary intake level sufficient to meet the nutrient requirement of 97% to 98% of healthy individuals in a specific group) for niacin varies for men and women.
The RDA (for ages 14 and over) is:
- Men: 16 milligrams
- Women: 14 milligrams (18 milligrams during pregnancy and 17 milligrams during lactation)
These foods contain niacin:
- Beef liver (14.9 mg/3 ounces cooked)
- Brown rice (5.2 mg/1 cup cooked)
- Chicken breast (10.3 mg/3 ounces cooked)
- Enriched cereals (5 mg/serving)
- Lentils (1 mg/ ½ cup cooked)
- Marinara sauce (10.3 mg/1 cup)
- Peanuts (4.2 mg/1 ounce)
- Potatoes (2.3 mg/1 medium baked)
- Pumpkin seeds (1.3 mg/1 ounce)
- Salmon (8.6 mg/3 ounces cooked)
- Sunflower seeds (2 mg/1 ounce)
- Tuna (8.6 mg/3 ounces canned)
- Turkey breast (10 mg/3 ounces cooked)
- Whole-wheat bread (1.3 mg/slice)
Niacin is found in smaller amounts in soy milk, bulgur, bananas, edamame, raisins, tomatoes, broccoli, milk, spinach, apples, and cashews.
What are the Benefits of Taking Niacin Supplements?
While niacin is readily available in the American diet, says Crean, it is sometimes prescribed in higher doses. Research shows that supplementing with niacin under a doctor’s supervision can potentially help those with concerns pertaining to cardiovascular health.
What Are The Risks of Taking Niacin Supplements?
Taken regularly in high doses (typically greater than 1 gram), niacin has been shown to increase the risk of several health issues, including:
- Abdominal pain
- Blurred or impaired vision
- Glucose intolerance
- Liver toxicity
What is a Niacin Flush?
Supplementing with smaller doses (typically 30mg to 50mg) can cause the dilation of blood vessels in the face, chest, and neck, causing flushed skin. This “niacin flush” is usually temporary — setting in after about 30 minutes and typically not lasting longer than about an hour — but if you’re concerned, don’t hesitate to consult your doctor.