Niacin

Encyclopedia of Alternative Medicine, Apr 06, 2001 by Judith Turner

Niacin, also known as Vitamin B3, is important for the normal function of many bodily processes. Like other B vitamins, it is water-soluble and plays a role in turning food into energy, as well as in the metabolism of fats and carbohydrates. Niacin can also act as an antioxidant within cells, which means it can destroy cell-damaging free radicals. In conjunction with riboflavin and pyridoxine, it helps to keep the skin, intestinal tract and nervous system functioning smoothly.

The recommended daily allowance (RDA) of niacin for infants under six months is 5 mg. Babies from six months to one year of age require 6 mg. Children need 9 mg at one to three years of age, 12 mg at four to six years, and 13 mg at seven to 10 years. Women need 15 mg from 11-50 years, and 13 mg thereafter. Somewhat more is required for pregnancy (17 mg) and lactation (20 mg). Men require 17 mg from 11-14 years of age, 20 mg from 15-18 years, 19 mg from 19-50 years, and 15 mg at 51 years and older.

Niacin, in the form of nicotinic acid, can be taken in very large doses to decrease cholesterol and reduce the risk of heart attack . The amount required is between 2 and 3 g. This is not a therapy that should be undertaken without professional medical advice and supervision. Certain conditions preclude the use of high doses of niacin. These include gout, diabetes, peptic ulcer, liver or kidney disease, and high blood pressure requiring medication. Even in the absence of these conditions, a patient on high doses of niacin should be closely monitored to be sure the therapy is both effective and without complications. A frequent side effect of this therapy is extreme flushing of the face and neck. It is harmless, but can be unpleasant. An alternative form of nicotinic acid that does not cause flushing is inositol hexaniacinate. "Slow release" niacin also causes less flushing, but should not be taken as there is higher risk of liver inflammation.

There is some evidence that niacinamide used on a long-term basis can prevent the onset of juvenile diabetes in many susceptible children. Those who have been newly diagnosed with juvenile diabetes may also benefit by extending the time that the pancreas continues to produce a small amount of insulin. The advice of a health care provider should be sought for these uses.

Inositol hexaniacinate can be helpful for people suffering from intermittent claudication. This condition causes leg pain with exercise due to poor blood flow to the legs. Dilation of the blood vessels caused by the inositol hexaniacinate relieves this condition to some extent, allowing the patient to walk farther with less pain.

Other conditions that may be benefited by supplemental niacinamide include vertigo, tinnitus, premenstrual syndrome (PMS) headaches, and osteoarthritis. Raynaud's phenomenon reportedly may be improved by large doses of inositol hexaniacinate. A health care provider should be consulted for these uses. Niacin is not effective for the treatment of schizophrenia.

Tuna is one of the best sources of niacin, but many foods contain it. Most processed grain products are fortified with niacin, as well as other B vitamins. Although niacin is not destroyed by cooking, it does leach into water, so cooking with minimal liquid best preserves it. The amino acid tryptophan is widely found in foods high in protein, and about half of the tryptophan consumed is used to make niacin. Cottage cheese, milk, fowl, and tuna are some of the foods that are highest in tryptophan.

Niacin can be purchased as an oral single vitamin product. A balanced B complex supplement is preferred over high doses of an individual vitamin unless there is a specific indication. Supplements should be stored in a cool, dry place, away from light, and out of the reach of children.

A serious deficiency of niacin causes a condition called pellagra. Once quite common, it has become rare outside of areas where poor nutrition is still the norm. The symptoms include dermatitis, dementia, and diarrhea.

Milder deficiencies of niacin can cause similar, but less severe symptoms. Dermatitis, especially around the mouth, and other rashes may occur, along with fatigue, irritability, poor appetite, indigestion, diarrhea, headache, and possibly delirium.

Severe niacin deficiency is uncommon in most parts of the world, but some people may need more than the RDA in order to maintain good health. Vegans, and others who do not eat animal protein, should consider taking a balanced B vitamin supplement. Others that may need extra niacin and other B vitamins may include people under high stress, including those experiencing chronic illnesses, liver disease, sprue, or poor nutritional status. People over 55 years old are more likely to have a poor dietary intake. Certain metabolic diseases also increase the requirement for niacin. Those who abuse nicotine, alcohol or other drugs are very frequently deficient in B vitamins, but use of niacin with alcohol can cause seriously low blood pressure. A health care professional can determine if supplementation is appropriate.