This seems to nullify any value the niacin has, so why does the Food and Drug Administration allow OTC niacin with the antiflushing additive to be sold when it obviously does no good?

DEAR READER: High-density lipoprotein cholesterol (HDL) is often identified as the “good” cholesterol because it helps to keep low-density lipoproteins (LDL) from building in the arteries. High levels of HDL appear to help protect people from coronary artery disease.

If your HDL levels were low, the natural place to begin was with appropriate diet and exercise. That is not to imply you are or were overweight. Rather, it refers to eating foods low in cholesterol and avoiding luncheon meats, fried foods, ice cream, cheese and a host of other items.

If that failed to produce results, over-the-counter supplements such as niacin, a water-soluble vitamin B3 supplement, might be appropriate. OTCs include regular and nonflushing forms. I cannot confirm that the nonflushing type is less effective for everyone in lowering cholesterol levels and raising HDLs than regular niacin, but this often appears to be the case.

Now, on to the FDA. In most instances, manufacturers are responsible for the safety of a product but are not required to register or obtain approval before producing or selling dietary supplements. OTC supplements don’t even require documentation of efficacy or proof that they will be effective.

The contents of OTC preparations of niacin are not federally regulated in the United States. Those marketed as nonflushing may not contain nicotinic acid and, as such, are likely ineffective. SOME formulations of sustained-release niacin such as Slo-Niacin and perhaps Endur-acin appear to be relatively safe, while other OTC sustained-release niacin formulations have been associated with an increased risk of hepatotoxicity. OTC immediate-release niacin preparations are inexpensive, contain a full amount of free nicotinic acid, and are safer than most sustained-release preparations. Sustained-release Niaspan (which you may have been prescribed) is more expensive but appears to be safe, effective and should not cause flushing. Your physician should have informed you that the nonflushing formulations don’t work for everyone. When a patient experiences flushing, he or she may be helped by taking one antihistamine or aspirin 15 to 30 minutes before taking niacin. I typically recommend the antihistamine because aspirin is more likely to interact with some medications, and cause bruising, excessive bleeding and other unwanted side effects.

To provide related information, I am sending you a copy of my Health Report “Understanding Cholesterol.” Other readers who would like a copy should send a self-addressed stamped No. 10 envelope and a $2 check or money order to Newsletter, P.O. Box 167, Wickliffe, OH 440902-0167. Be sure to mention the title or print an order form off my website at www.AskDrGottMD.com.