This B-vitamin has been in the limelight as a potent cholesterol-lowering agent that rivals some prescription drugs in effectiveness. But niacin in its various forms also shows promise in the prevention and treatment of depression, arthritis and a host of other ailments.
What it is?
Also known as vitamin B3, niacin is available as a supplement in two forms: nicotinic acid (or nicotinate) and niacinamide. The body can also make niacin by converting the amino acid tryptophan – found in eggs, milk and poultry – into the vitamin. About half of the niacin supplied by the average diet comes from the body's processing of tryptophan.
In supplement form, both nicotinic acid and niacinamide can satisfy your nutritional requirement for this B-vitamin, but each has its own specific role in treating disease.
What it does?
Niacin is needed to release energy from carbohydrates. It is also involved in controlling blood sugar, keeping skin healthy, and maintaining the proper functioning of the nervous and digestive systems.
High doses of niacin raise HDL ('good') cholesterol while lowering LDL ('bad') cholesterol and triglyceride levels. In fact, studies show that niacin may be more effective than prescription cholesterol-lowering drugs in reducing the risk of heart disease, mainly because it is one of the few agents known to boost HDL. The cholesterol-lowering form of niacin is nicotinic acid, which must be taken under medical supervision, as it can cause skin flushing and, at high doses, liver damage.
Niacin relaxes blood vessels, making it useful for circulatory problems, such as intermittent claudication (a painful cramping in the calf caused by poor blood circulation that often occurs after walking) and Raynaud's disease (a disorder characterized by numbness and often pain in the hands or feet when exposed to cold).
Niacin also helps to foster healthy brain and nerve cells, and there's some evidence that niacinamide can ease depression, anxiety and insomnia. Niacinamide seems to have an anti-inflammatory effect, which may benefit those with rheumatoid arthritis. It may also help to heal damaged cartilage, making it potentially valuable for osteoarthritis. High doses of niacinamide may reverse the development of type I diabetes – the form that typically appears before the age of 30 – if it is given early enough. This therapy should be tried only under medical supervision.
- Lowers cholesterol.
- May improve circulation.
- May ease symptoms of arthritis.
- May relieve depression.
- Consult your doctor before using any form of niacin if you have any of the following conditions: diabetes, low blood pressure, bleeding problems, glaucoma, gout, liver disease or ulcers. All can be aggravated by niacin.
- If you take a daily therapeutic dose of 1000 mg or more of any form of niacin, see a doctor every three months to have your liver enzymes measured.
- Reminder: If you have a medical or psychiatric condition, talk to your doctor before taking supplements.
How much you need?
The RDI for niacin is 13 mg for women and 19 mg for men daily. But much higher doses are needed to lower cholesterol and treat other disorders.
If you get too little
A slight niacin deficiency can cause patches of irritated skin, appetite loss, indigestion and weakness. Severe deficiencies (which are practically nonexistent in industrialized countries) result in pellagra, a debilitating disease. Symptoms include a rash in areas exposed to sunlight, vomiting, a bright red tongue, fatigue and memory loss.
If you get too much
Therapeutic doses of nicotinic acid may cause stomach upset, flushing and itching of the skin, and liver damage. (At high doses, niacinamide also may harm the liver.) But if you're taking any form of niacin for long periods, ask your doctor to do periodic blood tests to monitor your liver.
How to take it?
For lowering cholesterol or treating Raynaud's disease: Take 500 mg of niacin three times a day. When trying to reduce cholesterol, use the vitamin for two months; if your cholesterol levels are unchanged, stop taking the supplement.
For anxiety and depression: Take 50 mg of niacin a day; this dosage can usually be found in a vitamin B complex.
For insomnia: Take 500 mg of niacinamide one hour before bedtime.
For arthritis: Take 1000 mg of niacinamide three times a day, but only under a doctor's supervision.
Guidelines for use
Take any form of niacin with meals or milk to decrease the likelihood of stomach upset. Don't take therapeutic doses of any form of niacin if you take cholesterol-lowering prescription drugs.
Niacin is found in foods high in protein, such as chicken, beef, fish and nuts. Breads, cereals and pasta are often enriched with niacin. Though they're low in niacin, milk and other dairy products, as well as eggs, are good sources of the vitamin because they're high in tryptophan.
- Don't use over-the-counter timed-release niacin. It was developed to stop the skin flushing that high doses of nicotinic acid can cause, but studies show that it can damage the liver.
- In a US study of niacin's effect on high cholesterol, participants who took niacin supplements had a 17% drop in LDL ('bad') cholesterol levels, a 16% rise in HDL ('good') cholesterol levels and an 18% reduction in triglyceride levels.
- In a study of niacinamide's effect on osteoarthritis, researchers found that people who took it for 12 weeks experienced more joint flexibility, less inflammation and less need for anti-inflammatory drugs than those who were given a placebo.
Did you know?
Pasta is often enriched with niacin. But you'd have to eat about 7 cups of cooked pasta to meet the RDI for this vitamin