Specifically, vitamin B3 plays an important role in digestion, mental health, heart health, the nervous system, maintaining healthy skin, making a variety of hormones, and acting as a precursor to the coenzyme nicotinamide adenine dinucleotide (NAD+). Here, learn all about vitamin B3, its different forms and health benefits, signs of deficiency, common food sources, and when to consider a supplement. Of these, nicotinic acid and nicotinamide are the main forms of vitamin B3 or niacin—they’re both widely available from the same food sources and sold as dietary supplements. NR, on the other hand, is quite scarce in food and only recently started being sold as a supplement. All three forms of vitamin B3 are converted to an important coenzyme called NAD+ in the body. NAD+ is found in all living cells, and it plays a vital role in energy metabolism and maintaining proper cell functioning—particularly the functioning of our mitochondria, the power plants in our cells that turn food and oxygen into energy. It also plays an important role in protecting cells all over the body from age-related damage and decline in function. While all three forms of vitamin B3 share common traits, each has a slightly different effect on the body and serves a different role when taken as a supplement: Nicotinic acid: This form of vitamin B3 is readily available from food. As a supplement, it’s frequently used to manage high cholesterol and heart disease, and it often just goes by the name niacin. It also promotes circulation, and supplemental doses can cause what’s called “niacin flush,” skin that becomes red and itchy. Our bodies can convert nicotinic acid into nicotinamide. [Pro tip: Many articles that reference “niacin” without specifying which form usually mean nicotinic acid—even though niacin is technically a blanket term. It’s confusing, so we’ll call everything by its true name in this article.] Nicotinamide (aka niacinamide): This form of vitamin B3 is also readily available from food. It’s the form that typically appears in multivitamins and fortified foods, like cereal, since it does not cause flushing. As a supplement, it doesn’t treat cardiovascular conditions, but it does hold promise for treating skin3 conditions, arthritis4, and early-onset type 1 diabetes. Increasingly, it’s also being added to skin care products (where it’s often listed as niacinamide) for its anti-inflammatory and photoprotective perks. Nicotinamide riboside (NR): Found predominantly in NR supplements (and in trace amounts in milk), NR is the most recently discovered form of vitamin B3. It’s not commonly used, but it holds great promise in boosting cognitive function and slowing the aging process. Compared to the other two forms of vitamin B3, it is the most efficient5 at supporting neuronal NAD+ synthesis in the body and brain, which is really appealing. “Appropriate levels of NAD+ are critical to support the body’s response to stress,” Ilene Ruhoy, M.D., Ph.D., integrative neurologist, told mbg.* “That’s because NAD+ is used by enzymes to modulate cellular activity in response to extrinsic and intrinsic assaults, including those triggered by environmental toxins, pro-inflammatory foods, trauma, and even chronic use of medication.” But even though some research is promising, cardiologists like Joel Kahn, M.D., warn that this vitamin is not always a foolproof fix. “Generally we only need about 20 to 35 mg a day of niacin, but doses of up to 3,000 mg a day or more are used to control cholesterol,” Dr. Kahn told mbg—and these high doses can be associated with issues like ulcers, muscle damage, and gout. So, before taking high doses of vitamin B3 to help control cholesterol, always talk with your doctor to make sure it’s the right approach. Tweaking your diet and exercising could be all you need! In one animal study8, use of a topical cream containing nicotinamide decreased the risk of UV-induced skin cancers in mice. And in humans, a recent analysis9 of two prospective cohort studies following men and women for up to 26 years found that higher dietary intake of vitamin B3 (from food and oral supplements) may offer protection against certain types of skin cancer. This is good news since it suggests that you can consume enough vitamin B3 from food to reap this benefit. Sunscreens containing nicotinamide (where it’s usually listed as niacinamide) are already on the market and may offer further protection. A recent clinical trial10 also found that taking an oral nicotinamide supplement may have protective effects against damage from UV radiation and reduce the rate of new, non-melanoma skin cancers. More research is needed before nicotinamide can be recommended for preventing skin cancer. More studies are needed to confirm appropriate dosing of nicotinamide for acne. If you’re interested in taking it orally to manage skin conditions, talk to a dermatologist first to make sure it’s the best possible option—not everyone’s fully on board yet. Some over-the-counter facial cleansers and creams containing nicotinamide containing lower doses than what has been used in studies may be a safe option to experiment with, just watch out for potential side effects such as skin irritation. Adding a high-dose nicotinamide supplement for osteoarthritis relief should only be done under the supervision of your doctor, as nicotinamide makes it more difficult to clear uric acid from your body, which could increase your risk for gout, another painful joint condition. The form of vitamin B3 known as NR is of particular interest when it comes to brain health and Alzheimer’s prevention. In a recent study7, researchers found that the NR-treated mice had less DNA damage, higher neuroplasticity, increased production of new neurons, and lower levels of neuronal damage. In the hippocampus area of the brain (where damage and loss of volume is found in dementia), NR seemed to clear existing DNA damage or prevent it from spreading further. The mice also performed better on memory tests. But studies on NR’s long-term effects on human health are still few and far between. Much more research is needed to determine if it would have a similar effect. Preliminary research links vitamin B3 to digestive ailments such as irritable bowel syndrome, but further research is warranted. In the meantime, know that human studies looking at treatment with high supplemental doses of nicotinic acid has been associated with ulcers in the digestive tract. So for now, focus on eating quality food sources of vitamin B3, and don’t self-treat with supplements unless you consult with a doctor. Nutritional yeast (¼ cup): 46 mg Turkey (3 oz): 10 mg Chicken (3 oz): 9 mg Tuna (3 oz, canned): 8½ mg Salmon (3 oz): 8½ mg Bran flakes (¾ cup): 5 mg Beef (3 oz): 4½ mg Peanuts (1 oz): 4 mg Mushrooms (1 sliced cup): 2½ mg Lentils (1 cooked cup): 2 mg Coffee (1 brewed cup): 2 mg Whole-wheat bread (1 slice): 1½ mg Beets (1 sliced cup): 1 mg Add a drizzle of olive oil and a sprinkle of nutritional yeast to your next batch of popcorn for a cheesy flavor that’s totally vegan! Common symptoms of mild vitamin B3 deficiency, which can usually be addressed with diet changes and/or a multivitamin, often include indigestion, fatigue, canker sores and/or a bright red tongue, poor circulation, and depression. Severe vitamin B3 deficiency is known as pellagra19. This disease affects the skin, digestive system, and nervous system and can be deadly if it’s not treated. Symptoms, which can be treated with a prescription nicotinic acid or nicotinamide supplement from your doctor, often include delusions or mental confusion, scaly and cracked skin, a swollen mouth, diarrhea, vomiting, headaches, fatigue, and depression. If you’re interested in using a vitamin B3 supplement to manage a minor health condition on your own, it’s still wise to consult a health care provider about the appropriate dose and form. Many nicotinic acid and nicotinamide supplements contain doses that are far higher than the RDA (typically around 500 mg per dose), which could be dangerous or cause side effects if taken unnecessarily or incorrectly. If you want to supplement, integrative doctor Andrew Weil, M.D. recommends 50 mg of vitamin B3 in the form of nicotinamide (sometimes listed as niacinamide) as part of a B-complex vitamin. For both forms, minor side effects include diarrhea, headache, stomach discomfort, and bloating. They may also make seasonal allergies worse, as they trigger the release of histamine. With doses above 50 mg, nicotinic acid may also cause “niacin flush,” or red flushed skin along with a burning or tingling sensation in the face or chest. Slow-release alternatives to nicotinic acid (under the name inositol hexaniacinate) may reduce flushing. With very high doses of vitamin B3, like those used to treat specific health conditions, these supplements may cause liver damage, stomach ulcers, and nausea and vomiting, among other side effects. That’s why doctors recommend periodic blood tests to check liver function with doses above 100 mg per day. High doses may also increase blood sugar, so people with diabetes should be cautious. Vitamin B3 supplements could also interfere with a variety of medications, including common antibiotics and blood thinners, so always be sure to talk with your doctor about interactions before taking either of these forms of vitamin B3. It’s an exciting nutrient that could turn out to be a game-changer in healthy aging. (For more info, read our complete guide to NR.) If you are pregnant, breastfeeding, or taking medications, consult with your doctor before starting a supplement routine. It is always optimal to consult with a health care provider when considering what supplements are right for you.ad
