What Is It?
Also known as vitamin B3, niacin has earned a reputation (in supplement form) as a natural cholesterol-lowering agent that often rivals prescription drugs in mild to moderate cases. It may also help to prevent or treat a number of other disorders, from arthritis and depression to diabetes. Three forms of niacin supplements–each with a specific therapeutic role–are commercially available: nicotinic acid (also called nicotinate), niacinamide and inositol hexaniacinate, a compound of niacin and inositol (another B-family vitamin).
Normally, the body manages to absorb enough niacin from foods to carry out basic functions, working on the cellular level to keep the digestive system, skin and nerves healthy. This vitamin is also critical to releasing energy from carbohydrates and helping to control blood-sugar levels. Interestingly, the body also synthesizes niacin from tryptophan, an amino acid found in eggs, milk and poultry.
Although few people in the industrialized world are actually deficient in niacin, many may benefit from additional amounts in supplement form to help treat assorted complaints. Keep in mind that each of the three forms of niacin affects the body differently. Niacinamide has notable anti-inflammatory properties, for example, while nicotinic acid and inositol hexaniacinate affect blood lipid levels and circulation.
Specifically, niacin may help to:
Control cholesterol. Unlike most prescription cholesterol-lowering medications, which simply lower levels of LDL (“bad”) cholesterol and triglycerides, niacin also raises levels of HDL (“good”) cholesterol. As a result, this vitamin may prove more potent than conventional medicines in ultimately reducing the risk for a heart attack (and death from a heart attack). In a recent study of people with high cholesterol, niacin not only reduced LDL and triglycerides by 17% and 18%, respectively, but it also increased HDL by 16%. Although both nicotinic acid and inositol hexaniacinate have cholesterol-benefiting actions, inositol hexaniacinate is the preferred form–it doesn’t cause skin flushing and poses much less risk of liver damage with long-term use.
Combat Raynaud’s disease and other circulatory problems. Niacin improves circulation by relaxing arteries and veins, and disorders characterized by circulation difficulties may benefit as a result. In those suffering from Raynaud’s disease, for example, niacin’s ability to improve blood flow to the extremities may counter the numbness and pain in the hands and feet that occurs when blood vessels overreact to cold temperatures. The calf-cramping and other painful symptoms of intermittent claudication, another circulation disorder, may lessen under the vessel-relaxing influence of niacin as well. The inositol hexaniacinate form of niacin works best for circulation-related discomforts.
Fight depression. Based on niacin’s well-recognized role in promoting the sound functioning of nerve cells, some experts recommend the vitamin for relieving depression as well as for soothing feelings of anxiety and panic. Most B-vitamin complexes contain sufficient amounts of niacin for this purpose; as an added plus, the complexes also offer the mood-enhancing benefits of other B vitamins.
Ease symptoms of arthritis and rheumatoid arthritis. The anti-inflammatory properties associated with niacinamide may help in calming joint inflammation, a frequent cause of rheumatoid arthritis pain. In a double-blind, 12-week study, osteoarthritis sufferers who received niacinamide supplements reported less inflammation and greater joint flexibility than other participants who were given a placebo. The niacinamide group also required less conventional anti-inflammatory medication to relieve their customary pain and swelling.
Slow progression of type 1 diabetes. High doses of niacinamide, if given at the first signs of the disease, appear to help prevent complications of insulin-dependent diabetes and may even help reverse its development. This complementary supplement treatment should only be undertaken with careful medical supervision, however.
Treat tinnitus. The persistent ringing, humming and buzzing in the ears associated with this condition has been linked to poor blood circulation. By widening blood vessels in the brain, inositol hexaniacinate may help to relieve these and other tinnitus symptoms.
Note: Niacin has also been found to be useful for a number of other disorders. For information on these additional ailments, see our Dosage Recommendations Chart for Niacin.
The RDA for niacin is 14 mg for women and 16 mg for men. Specific disorders usually require higher doses.
If You Get Too Little
A deficiency in niacin can result in pellagra, a skin disorder characterized by small patches of dry, scaly irritated skin in sunlight-exposed areas. Other symptoms include loss of appetite and strength, and digestive complaints. Severe cases can involve headache, memory loss and depression. Pellagra is now quite rare in the industrialized world.
If You Get Too Much
It’s nearly impossible to get too much niacin from foods. This is not the case with supplements, however. Keep in mind that megadoses can cause serious side effects, such as abdominal cramping, nausea, and vomiting; lightheadedness; ulcers; and skin rashes, flushing or itching. Liver damage is also a risk with long-term use of niacinamide and nicotinic acid. Inositol hexaniacinate in doses higher than 2,000 mg a day may have a blood-thinning effect.
General Dosage Information
Special tips: Most multivitamins and B-complex supplements provide the RDA for niacin. Dosages adequate for treating specific ailments are typically found in individual niacin supplements, however.
–In general, niacin in the form of inositol hexaniacinate and niacinamide tends to cause fewer side effects than nicotinic acid.
For treating high cholesterol, Raynaud’s disease, intermittent claudication or tinnitus: Take 500 mg of inositol hexaniacinate three times a day. Continue for two months if your goal is to lower cholesterol. Stop at this point if cholesterol levels haven’t improved.
For anxiety or depression: A vitamin B-complex supplement will typically provide the amount of niacin (50 mg a day) necessary for treating these conditions.
For arthritis: Take 1,000 mg of niacinamide three times a day.
Be sure to check out our Dosage Recommendations Chart for Niacin, which lists therapeutic dosages for specific ailments at a glance.
Guidelines for Use
Take niacin supplements with meals or a glass of milk to prevent stomach discomfort.
Niacin acts like a drug when taken in high doses (1.5 to 6 grams a day). If you’re contemplating using niacin in this dosage range, consult a doctor for supervision.
When possible, substitute inositol hexaniacinate for niacinamide and nicotinic acid. Inositol hexaniacinate is the safest form available, causing no skin flushing and posing considerably less risk of liver damage.
Use caution when taking large, therapeutic doses of niacin–in any form–if you’re already on one of the cholesterol-lowering prescription drugs known as statins. Muscle pain and inflammation, and even kidney failure, are a risk if you mix niacin with any of the statins. Stop taking the drug and call your doctor immediately if any of the above symptoms occur.
Note: For information on interactions with specific generic drugs, see our WholeHealth Chicago Drug/Nutrient Interactions Chart.
Check with your doctor before taking niacin if you suffer from diabetes, low blood pressure, glaucoma, gout, liver disease, ulcers or a bleeding disorder. Niacin supplements may aggravate these conditions.
Have your doctor schedule blood tests every three months to check liver function if you take any form of niacin in amounts of 1,000 mg or more daily.
Don’t take timed-release niacin, an over-the-counter cholesterol drug designed specifically not to cause nicotinic acid-related skin flushing. Research indicates it may cause liver damage.
Stick to recommended doses; excessive amounts can cause serious health problems.
Diabetes 500 mg inositol hexaniacinate 3 times a day
High Cholesterol 500 mg 3 times a day
Raynaud’s disease 500 mg 3 times a day
Tinnitus 500 mg inositol hexaniacinate 3 times a day
David Edelberg, MD