Basics Print Niacin Requirements and Dietary Sources By Shereen Lehman, MS Updated July 14, 2019 Medically reviewed by a board-certified physician Robert Benson/Getty Images More in Basics Hot Topics Food Safety Niacin is a member of the water-soluble family of B-complex vitamins. Also known as vitamin B3, niacin is required for normal digestive function, converting the food you eat into energy and for healthy skin and nervous system function. It's also helpful for blood circulation, and your adrenal glands need niacin to make hormones such as cortisol, testosterone, and estrogen. Niacin deficiency is rare in modern Western diets—it usually occurs as a consequence of alcoholism. Symptoms of a mild niacin deficiency include digestive upset, fatigue, canker sores, vomiting, and depression. Pellagra is caused by a full-blown niacin deficiency. Symptoms include dementia, diarrhea, sores on the skin, and may lead to death. The Health and Medicine Division of National Academies of Sciences, Engineering, and Medicine sets the daily dietary reference intakes (DRI) for vitamins and minerals. The DRI for niacin is determined by age and sex. Women who are pregnant or breastfeeding need the largest amounts. The DRIs are based on what an average healthy person needs—if you have any health conditions you should speak with your healthcare provider about your niacin requirements. Dietary Reference Intakes Males DRI 1 to 3 years 6 milligrams (mg) per day 4 to 8 years 8 mg per day 9 to 13 years 12 mg per day 14+ years 16 mg per day Females DRI 1 to 3 years 6 mg per day 4 to 8 years 8 mg per day 9 to 13 years 12 mg per day 14+ years 14 mg per day Pregnancy 18 mg per day Breastfeeding 17 mg per day Niacin is found in a variety of foods including dairy products, poultry, fish, lean meats, nuts, legumes, eggs, and vitamin-fortified foods. Since it's easily obtained from many different foods, most people don't need to take supplements to ensure adequate intake. Niacin Supplements and Cholesterol When taken in large doses, niacin supplements may be used to reduce elevated triglycerides and LDL cholesterol levels in the blood and to increase levels of HDL cholesterol (generally considered healthy cholesterol). Although it's available as an over-the-counter supplement, taking extra niacin may cause problems: Ingesting large amounts of supplemental niacin may result in liver damage, can interact with some types of medications, and might increase glucose levels in people with diabetes. Speak to your doctor if you're thinking about taking niacin for cholesterol support. Taking niacin in large amounts may also cause an uncomfortable reaction called the niacin flush, which includes a burning and itching sensation of the face and joints. It's not dangerous, but it can be frightening if it happens. Using No-Flush Niacin to Lower Cholesterol Due to these reactions and safety concerns, the Institute of Medicine established 35 milligrams per day as the upper tolerable intake level of niacin for adults. No matter what form of niacin is used, large doses should only be used under the supervision of a physician. Was this page helpful? Thanks for your feedback! Looking to lose weight? Our nutrition guide can help you get on the right track. Sign up and get it free! Email Address Sign Up There was an error. Please try again. Thank you, , for signing up. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Gropper SS, Smith JL, Groff JL. "Advanced Nutrition and Human Metabolism." Sixth Edition. Belmont, CA. Wadsworth Publishing Company, 2013. Health and Medicine Division of National Academies of Sciences, Engineering, and Medicine. "Dietary Reference Intakes Tables and Application." http://www.nationalacademies.org/hmd/activities/nutrition/summarydris/dri-tables.aspx. National Institutes of Health Medline Plus. "Niacin." http://www.nlm.nih.gov/MEDLINEPLUS/ency/article/002411.htm. National Institutes of Health Medline Plus. "Pellagra." http://www.nlm.nih.gov/medlineplus/ency/article/000342.htm. Continue Reading How to Prevent a Niacin or Vitamin B Flush Health Benefits and Uses of Niacin Zinc Requirements and Dietary Sources How Much Magnesium Do You Need in Your Diet? Can You Really Overdose on Vitamins? Molybdenum Requirements and Dietary Sources Chloride Requirements and Dietary Sources Your Body Requires Iodine for Growth and Metabolism Chromium Requirements for Health Is Based on Age and Sex The Benefits of Adding Phosphorus to Your Diet How Vitamin C Supplements Can Help With Deficiency Water-Soluble Vitamins and Where to Find Them How (and Why) to Get More Selenium in Your Diet Riboflavin Requirements and Dietary Sources Vitamin B-6 Requirements and Dietary Sources Why Are B Complex Vitamins Important to Your Health?