3-Pyridine carboxamide, anti-blacktongue factor, antipellagra factor, B-complex vitamin, benicot, Efacin®, ENDUR-ACIN®, Enduramide®, Hexopal®, NIAC®, Niacor®, Niaspan®, Nicalex®, nicamid, Nicamin®, Nico-400®, Nicobid®, Nicolar®, Nicotinex®, nicosedine, Nico-Span®, nicotinamide, nicotinic acid amide, nicotinic amide, nicotylamidum, Papulex®, pellagra preventing factor, Slo-Niacin®, Tega-Span®, Tri-B3®, Wampocap®.
Vitamin B3 is made up of niacin (nicotinic acid) and its amide, niacinamide, and can be found in many foods, including yeast, meat, fish, milk, eggs, green vegetables, and cereal grains. Dietary tryptophan is also converted to niacin in the body. Vitamin B3 is often found in combination with other B vitamins including thiamine, riboflavin, pantothenic acid, pyridoxine, cyanocobalamin, and folic acid.
High cholesterol (niacin):
Niacin is a well-accepted treatment for high cholesterol. Multiple studies show that niacin (not niacinamide) has significant benefits on levels of high-density cholesterol (HDL or "good cholesterol"), with better results than prescription drugs such as "statins" like atorvastatin (Lipitor®). There are also benefits on levels of low-density cholesterol (LDL or "bad cholesterol"), although these effects are less dramatic. Adding niacin to a second drug such as a statin may increase the effects on low-density lipoproteins.
The use of niacin for the treatment of dyslipidemia associated with type 2 diabetes has been controversial because of the possibility of worsening glycemic control. Patients should check with a physician and pharmacist before starting niacin.
Niacin (vitamin B3) and niacinamide are U.S. Food and Drug Administration (FDA)-approved for the treatment of niacin deficiency. Pellagra is a nutritional disease that develops due to insufficient dietary amounts of vitamin B3 or the chemical it is made from, tryptophan. Symptoms of pellagra include skin disease, diarrhea, dementia, and depression.
Niacin decreases blood levels of cholesterol and lipoprotein (a), which may reduce the risk of atherosclerosis ("hardening" of the arteries). However, niacin also can increase homocysteine levels, which may have the opposite effect. Overall, the scientific evidence supports the use of niacin in combination with other drugs (but not alone) to decrease cholesterol and slow the process of atherosclerosis. More research is needed in this area before a firm conclusion can be drawn.
Prevention of a second heart attack (niacin):
Niacin decreases levels of cholesterol, lipoprotein (a), and fibrinogen, which can reduce the risk of heart disease. However, niacin also increases homocysteine levels, which can increase this risk. Numerous studies have looked at the effects of niacin, alone and in combination with other drugs, for the prevention of heart disease and fatal heart attacks. Overall, this research suggests benefits of niacin, especially when combined with other cholesterol-lowering drugs.
Age-related macular degeneration (AMD):
Niacin may benefit the choroidal blood vessels, which underlie the region of the retina called the macula. Age-related macular degeneration (AMD) may result from disrupted blood flow in the choroidal vessels. Studies suggest that niacin may be used to treat AMD, but more well-designed studies are needed.
Alzheimer's disease/ cognitive decline:
Dementia can be caused by severe niacin insufficiency, but it is unclear whether variation in intake of niacin in the usual diet is linked to neurodegenerative decline or Alzheimer's disease (AD). Further research is needed before a conclusion can be drawn.
Diabetes (Type 1/Type 2):
Niacinamide may prevent diabetes or delay the need for insulin. More research is needed to determine if niacinamide delays or prevents the onset of insulin dependence in individuals with type 1 diabetes.
Niacin has been used to treat dyslipidemia associated with type 2 diabetes. However, this treatment has been controversial because it may worsen glycemic control. Patients should seek medical advice before starting niacin.
There is not enough information about the treatment or prevention of headaches with niacin. More research is needed.
High blood phosphorous level (hyperphosphatemia):
Niacinamide may reduce the high serum phosphate levels in hyperphosphatemia. However, more research is needed before niacinamide can be used to treat hyperphosphatemia.
A large, five-year study examined the effect of niacin supplementation on liver cancer. Although niacin did not appear to prevent liver cancer, deaths due to liver cancer were decreased in those who took supplements containing niacin. The ability of niacin to prevent liver cancer deaths should be further examined.
Preliminary human studies suggest that niacinamide may be useful in the treatment of osteoarthritis. Further research is needed before a recommendation can be made.
Niacinamide has been used in skin care products, including moisturizers, anti-aging products, and rosacea treatments. The benefits of niacinamide in skin care needs to be further studied before recommendations are made.
Taking niacin with food may reduce stomach upset and the risk of stomach ulcers. Doses usually start low and are gradually increased to minimize the common side effect of skin flushing. Taking aspirin or non-steroidal anti-inflammatory drugs (NSAIDs) at the same time during the first one to two weeks may reduce this flushing. Use of an antihistamine 15 minutes prior to a niacin dose may also be helpful. The flushing response may decrease on its own after one to two weeks of therapy. Extended release niacin products may cause less flushing than immediate release (crystalline) formulations, but may have a higher risk of stomach upset or liver irritation. In general, not all niacin products are equivalent. Patients switching from one product to another may have an increase or decrease in side effects.
The dietary reference intake established by the Food and Nutrition Board for niacin (in the form of niacin equivalents, 1 milligram niacin = 60 milligrams tryptophan) ranges from 16 to 18 milligrams daily for adults, with a maximum intake of 35 milligrams daily. 50 milligrams to 6 grams has been taken in divided doses for other conditions based on physician and pharmacist recommendations.
Niacinamide (nicotinamide) and niacin (nicotinic acid) are used in cosmetics, as well as hair and skin conditioning agents. The concentration of niacinamide varies from a low of 0.0001% in night preparations to a high of 3% in body and hand creams, lotions, powders, and sprays. Niacin concentrations range from 0.01% in body and hand creams, lotions, powders, and sprays to 0.1% in paste masks (mud packs). For skin conditions, 2-5% niacinamide cream has been used.
Niacin dosing may vary according to the condition it is being used to treat. In clinical studies, doses have included 500 milligrams (single dose) for age-related macular degeneration, 375 milligrams (single dose) for hyperphosphatemia, up to 1 gram daily for pellagra, up to 3 grams daily for diabetes, up to 3 grams daily for osteoarthritis, and up to 4.3 grams daily (either along or combined with other agents) for cardiovascular disease.
There is not enough scientific evidence to recommend the safe use of niacin or niacinamide in children. Niacinamide has been studied in children at daily doses of 150 to 300 milligrams per year of the child's age, or 25 milligrams per kilogram daily, for the prevention of type 1 diabetes mellitus in "high-risk" individuals. There is a lack of reported serious side effects, and safety and effectiveness are not clear. Patients should speak with a qualified healthcare provider if considering this therapy.
Most people taking niacin experience skin flushing and a warm sensation, especially of the face, neck, and ears when they begin treatment or increase dose. This reaction is usually mild, but has been intolerable enough to cause up to half of participants in studies to stop therapy. Dry skin and itching is also commonly experienced. Taking aspirin or non-steroidal anti-inflammatory drugs such as ibuprofen (Advil®, Motrin®), naproxen (Naprosyn®), or indomethacin (Indocin®) can reduce the flushing. Use of an antihistamine 15 minutes prior to a niacin dose may also be helpful. Slow-release niacin products may have less skin flushing than regular release niacin preparations or may simply delay the appearance of flushing. The flushing response often decreases on its own after one to two weeks of therapy. Mild stomach upset, nausea, vomiting, and diarrhea also may occur when beginning niacin therapy; these symptoms usually resolve with continued use.
More serious side effects include liver toxicity, worsening of stomach ulcers, and altered blood sugar or insulin levels or uric acid concentrations. Numerous case reports describe liver toxicity, including increased liver enzyme levels in the blood, skin yellowing (jaundice), fluid in the abdomen (ascites), or liver failure. Monitoring of liver blood tests while using niacin is recommended. While slow-release niacin products may have less skin flushing than regular release niacin preparations, they may worsen stomach and liver side effects. High doses of niacin may also cause low blood pressure.
Lactic acidosis, muscle cell damage (myopathy), and increased blood levels of creatine kinase (a marker of muscle damage) have been reported in studies.
Abnormal heart rhythms and heart palpitations have occurred in niacin studies. Based on human research, taking niacin alone or with colestipol may increase blood homocysteine levels. High levels of homocysteine have been associated with an increased risk of heart disease.
Rarely reported side effects include headache, tooth or gum pain, dizziness, breathing difficulty, increased anxiety, panic attacks, and decreased thyroid function (hypothyroidism). There are published accounts of temporary side effects of the eye including macular swelling and blurred vision as well as toxic amblyopia ("lazy eye"). These side effects resolved when niacin was stopped.
Use of niacin supplementation during pregnancy or breastfeeding is not recommended due to lack of sufficient research of safety and effectiveness.