Harvard Health Letters
QUESTION: I hope you can clear up some family confusion. My doctor gave me a prescription for Niaspan, but my wife found the same medication, niacin, at the supermarket at a much lower price. Is it a drug or a vitamin?
ANSWER: Niacin is a natural substance -- in fact, it's vitamin B3. Like other vitamins, it's required to keep the metabolism working properly. But the recommended dietary allowance (RDA) for B3 is only 18 milligrams a day, far less than the amount needed to improve cholesterol levels. Still, any dose of niacin can be sold as a "dietary supplement" without a doctor's prescription and without FDA oversight.
In the doses needed to improve cholesterol, niacin is a drug -- and a potent drug at that. On average, it can lower LDL ("bad") cholesterol levels by 10 percent to 25 percent. The statins and other lipid-lowering drugs can do even better, but niacin outshines them all for lowering triglyceride levels (down 20 percent to 50 percent) and raising HDL ("good") cholesterol levels (up 15 percent to 35 percent).
Niacin is actually the granddaddy of cholesterol-lowering drugs. It was the first medication to lower cholesterol levels (1955), the first to reduce heart attacks (1984), and the first to lower long-term mortality rates (1986). But since 1987, when lovastatin (Mevacor) was the first statin drug marketed in the United States, niacin has fallen into disuse. The reason is that it's harder to take, and it may produce unpleasant side effects.
