What it does in the body
Niacin is crucial for conversion of food into energy, and helps maintain normal functioning of the skin, nerves and digestive system.  It also helps regulate the body's energy, blood sugar, antioxidant mechanisms, and detoxification reactions.  It is essential to the development of a strong immune system.¹

Niacin supplementation has a favorable effect on several health conditions, especially high cholesterol levels² and various forms of mental illness.

Food Sources

• Some common food sources of niacin include yeast, wheat bran, peanuts, wild and brown rice, sesame and sunflower seeds, pine nuts, buckwheat, whole-grains, red chili peppers, barley, almonds and split peas.

• In many countries women and children, especially, suffer from severe deficiency symptoms caused by an inadequate supply of niacin, as well as a lack of iron, folate, and other micro-nutrients. While deficiency can be prevented by fortifying staple foods such as flour, orthomolecular scientists generally consider this to be a less than ideal  source due to the negative effects of white flour on the body.

Recommended Dietary Allowance

• The RDA for niacin ranges from 8 mg to 18 mg/day for pregnant women.³ 

Orthomolecular Dosage Range: Much higher than RDA levels.

• 300 mg/day or more. Orthomolecular physicians may prescribe several thousand mg/day, depending on circumstances.

Cardiovascular Disease
"It is well established that niacin helps reduce harmful cholesterol levels in the bloodstream. Niacin is one of the best substances for elevating high density lipoprotein cholesterol (the "good" cholesterol) and so decreases the ratio of the total cholesterol over high density cholesterol.

"The finding that niacin lowered cholesterol was soon confirmed by Parsons, Achor, Berge, McKenzie and Barker (1956) and Parsons (1961, 1961a, 1962) at the Mayo Clinic, which launched niacin on its way as a hypocholesterolemic substance. Since then it has been found to be a normalizing agent, meaning it elevates high density lipoprotein cholesterol, decreases low density and very low density lipoprotein cholesterol and lowers triglycerides. Grundy, Mok, Zechs and Berman (1981) found it lowered cholesterol by 22 percent and triglycerides by 52 percent and wrote, "To our knowledge, no other single agent has such potential for lowering both cholesterol and triglycerides."

"Elevated cholesterol levels are associated with increased risk of developing coronary disease. In addition to niacin, a typical diet generally recommended by orthomolecular physicians will tend to keep cholesterol levels down in most people. This diet can be described as a high fiber, sugar-free diet which is rich in complex polysaccharides such as vegetables and whole grains.

"With adequately high doses of niacin, it is possible to lower cholesterol levels even with no alteration in diet. E. Boyle, then working with the National Institutes of Health in Washington, D.C., quickly became interested in niacin. He began to follow a series of patients using 3 grams (3,000 milligrams) of niacin per day. He reported his conclusions in a document prepared for physicians involved in Alcoholics Anonymous by Bill W (1968). In this report, Boyle reported that he had kept 160 coronary patients on niacin for ten years. Only six died, against a statistical expectation that 62 would have died with conventional care. He stated, "From the strictly medical viewpoint I believe all patients taking niacin would survive longer and enjoy life much more." His prediction came true when the National Coronary Drug Study was evaluated by Canner recently. But Boyle's data spoke for itself. Continuous use of niacin will decrease mortality and prolong life."   From: Orthomolecular Medicine News Service, September 30, 2005. Niacin (Vitamin B3) Lowers High Cholesterol Safely. http://orthomolecular.org/resources/omns/v01n10.shtml

Multiple Sclerosis:
"New research confirms that niacinamide, also known as vitamin B-3, is a key to the successful treatment of multiple sclerosis and other nerve diseases.⁴ Niacinamide, say researchers at Harvard Medical School, "profoundly prevents the degeneration of demyelinated axons and improves the behavioral deficits."

This is very good news, but it is not at all new news. Over 60 years ago, Canadian physician H.T. Mount began treating multiple sclerosis patients with intravenous B-1 (thiamine) plus intramuscular liver extract, which provides other B-vitamins. He followed the progress of these patients for up to 27 years. The results were excellent and were described in a paper published in the Canadian Medical Association Journal in 1973.⁵

Mount was not alone. Forty years ago, Frederick Robert Klenner, M.D., of North Carolina, was using vitamins B-3 and B-1, along with the rest of the B-complex vitamins, vitamins C and E, and other nutrients including magnesium, calcium and zinc to arrest and reverse multiple sclerosis.^{6, 7}  Klenner's complete treatment program was originally published as "Treating Multiple Sclerosis Nutritionally," Cancer Control Journal 2:3, p 16-20. His detailed megavitamin protocol is now posted for all interested persons to read at http://www.tldp.com/issue/11_00/klenner.htm   From: Orthomolecular Medicine News Service, October 4, 2006. VITAMINS FIGHT MULTIPLE SCLEROSIS.  http://orthomolecular.org/resources/omns/v02n08.shtml
 

Cancer:
Research on biochemical and cellular aspects of DNA repair has stimulated an interest in the relationship between niacin intake and cancer risk in humans. Recently, a large case-control study found increased consumption of niacin, along with antioxidant nutrients, to be associated with decreased incidence of oral (mouth), pharyngeal (throat), and esophageal cancers in northern Italy and Switzerland. An increase in niacin intake of only 6.2 mg was associated with about a 40 per cent decrease in cases of cancers of the mouth and throat, while a mere 5.2 mg increase in niacin intake was associated with a similar decrease in cases of esophageal cancer.^{8, 9, 10}

Schizophrenia
"In 1952, Dr. Humphry Osmond and Abram Hoffer started a double-blind experiment comparing niacin, niacinamide, and placebo on a group of thirty acute schizophrenic patients. The sickest patients from each group (more depressed or more violent) also received a short series of electroconvulsive therapy. One year after discharge, each patient was reevaluated. From the placebo group, three patients were well (the usual spontaneous recovery rate is considered to be about 35 percent). The other two groups fared better: from each, about 75 percent were well, doubling the one-year natural recovery rate. Three more double-blind experiments confirmed these conclusions. Since then, the use of vitamin B3 has become standard practice for orthomolecular therapists, but it is important to note that vitamin B3 alone is seldom used for treating schizophrenia. It is usually combined with orthomolecular nutrition, with other vitamins and minerals, and for a while with standard neuroleptic drugs when they are required. This comprehensive program has been used on over 100,000 schizophrenics in North America with excellent results. When tranquilizers are used, smaller quantities are needed, and eventually, recovered patients do not need to use any tranquilizers."11  (From: Hoffer A and Saul AW. Orthomolecular Medicine for Everyone, Basic Health Publications, 2008.)

Arthritis:
"By 1950, William Kaufman, Ph.D., M.D., published The Common Form of Joint Dysfunction, including detailing the beneficial effects of vitamin B3 for arthritis. Dr. Kaufman presented meticulous case notes for hundreds of patients, along with specific niacinamide dosage information applicable to both osteoarthritis and rheumatoid arthritis. . . . Dr. Kaufman, known as a conservative physician, was nevertheless the first to prescribe as much as 5,000 mg of niacinamide daily, in many divided doses, to improve range of joint motion. . . . Regarding dosage, he stated that "the (more frequent) 250 mg dose of niacinamide is 40 to 50 percent more effective in the treatment of arthritis than the (less frequent) 500 mg dose. Niacinamide (alone or combined with other vitamins) in a thousand patient-years of use has caused no adverse side effects." But he also urged a conservative approach: "Some joints are so injured by the arthritic process that no amount of niacinamide therapy will cause improvement in joint mobility, but it takes three months of niacinamide therapy before you can conclude this, since some joints are slow to heal."

"One of Dr. Kaufman's patients was so severely arthritic that he could not bend his elbows enough for a blood pressure measurement. Dr. Kaufman gave him niacinamide for a week in divided doses, and then he could bend his arm. After then taking him off the B3 and giving him a look-alike medicine (placebo) for a week, the patient was back where he started: his joints were stiff again. "I arrived at my (megavitamin B3 dosage) schedule by actually seeing the response of patients with varying degrees of arthritis," stated Dr. Kaufman. "One cannot give a single large dose and get any really favorable results in arthritis . . . It is necessary to divide the doses so that the blood levels of niacinamide would be fairly uniform throughout the waking day."

"His findings were both plain and elegant: the greater the stiffness, the more frequent the doses. Severely crippled arthritic patients needed up to a total of 4,000 mg per day, divided into ten doses. In one to three months, patients could now get out of their chair or bed. "If continued, they would be able comb their hair and be able to walk upstairs, so they would no longer be prisoners of the house. By the end of about three years' treatment, they would be fully ambulatory, and this was even in the older age groups."  (From: Saul AW. Taking the cure: The pioneering work of William Kaufman: Arthritis and ADHD. J Orthomolecular Med, 2003. Vol 18, No 1, p 29-32.  http://www.doctoryourself.com/news/v3n16.txt)

References:
¹    The Linus Pauling Institute. Site viewed January 11, 2008. http://lpi.oregonstate.edu/infocenter/vitamins/niacin/
²    Ibid
³    Dietary Reference Intakes: thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin
⁴    Kaneko S, Wang J, Kaneko M, Yiu G, Hurrell JM, Chitnis T, Khoury SJ, He Z. Protecting axonal degeneration by increasing nicotinamide adenine dinucleotide levels in experimental autoimmune encephalomyelitis models. J Neurosci. 2006 Sep 20;26(38):9794-804. http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=pubmed
⁵    Mount HT. Multiple sclerosis and other demyelinating diseases. Can Med Assoc J. 1973 Jun 2;108(11):1356-1358.
⁶    Frederick R. Klenner. "Response of Peripheral and Central Nerve Pathology to Mega-Doses of the Vitamin B-Complex and Other Metabolites", Journal of Applied Nutrition, 1973, http://www.tldp.com/issue/11_00/klenner.htm
⁷    Dr. Klenner's "Clinical Guide to the Use of Vitamin C" (which discusses orthomolecular therapy with all vitamins, not just vitamin C) is now posted in its entirety at http://www.seanet.com/~alexs/ascorbate/198x/smith-lh-clinical_guide_1988.htm It includes a multiple sclerosis protocol, which takes up about five pages. See also: http://www.doctoryourself.com/klennerpaper.html
⁸    The Linus Pauling Institute. Site viewed January 11, 2008. http://lpi.oregonstate.edu/infocenter/vitamins/niacin/
⁹     Negri E, Franceschi S, Bosetti C, et al. Selected micronutrients and oral and pharyngeal cancer. Int J Cancer. 2000;86(1):122-127.  (PubMed)
¹⁰   Franceschi S, Bidoli E, Negri E, et al. Role of macronutrients, vitamins and minerals in the aetiology of squamous-cell carcinoma of the oesophagus. Int J Cancer. 2000;86(5):626-631.  (PubMed)
¹¹   Hoffer, A., and H. Osmond. "In Reply to the American Psychiatric Association Task Force Report on Megavitamins and Orthomolecular Therapy in Psychiatry." Regina, Saskatchewan, Canada: Canadian Schizophrenia Foundation, 1976.