Orthomolecular Vitamin Information Centre Inc.

There are two main forms: nicotinic acid, known medically as niacin, and nicotinamide which is known medically as niacinamide. The term vitamin B-3 refers to these two and to the nicotinamide adenine dinucleotide system, NAD and NADH. NADH is the reduced form and more active than NAD. The term vitamin B-3 deficiency means a deficiency of niacin, or of niacinamide, or of nicotinamide adenine dinucleotide (NAD) or its reduced derivative NADH. No-flush niacin is inositol niacinate. It dose not cause any flushing and is used as if it were niacin.

Niacin is not toxic to the liver. The notion that it is, is based upon a few observations, some of which were dead wrong. Between 1940 and 1950 when the toxicity of niacin and niacinamide was studied, the LD-50 on animals was determined. The LD 50 is the amount of compound that will kill one-half of the population of animals used to test toxicity. If 100 mice are given the drug and half die that dose is the LD50; for niacin it is very high, about 4.5 grams per kilogram. This is equivalent to 225 grams (nearly half a pound) for a 110 pound female and 360 grams for a 176 pound male, or approximately 100 times as much as is normally recommended. At autopsy the animals showed elevated fatty acids in the liver.

Using the electron microscope the Mayo Clinic examined the livers of a series of their patients on niacin being treated for high blood cholesterol, and they found no evidence of pathology. This was first reported by Dr. William Parsons Jr1 (www.cholesterolnodiet.com). Dr. Parsons points out that increase in the liver function tests, unless they are very substantial i.e. over threefold, do not indicate liver pathology. There are many compounds that elevate liver enzymes including all the statins. In most patients with elevated liver function tests the values become normal in a few days even if the niacin is not discontinued. We advise all doctors that they should stop the niacin for at least five days before doing the test. With real liver pathology they will not be normal in five days, but when they are elevated with niacin they are normal within these five days

There are a few side effects which may be a nuisance, but these are not toxic reactions. Apart from a very few subjects who are allergic to the pills, either the active component or some of the fillers, most of these reactions are dose related. People must not take niacin unless they are informed of the possible side effects, both positive and negative.

1 Parsons Jr WB: The Effect of Nicotinic Acid on the Liver. Evidence Favoring Functional Alteration of Enzymatic Reactions Without Hepatocellular Damage. In Niacin in Vascular Disorders and Hyperlipemia. Ed R Altshul. CC Thomas, Springfield, Ill. 1964.

Disclaimer: The information presented here is for educational purposes only.

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Vitamin B-3