Guidelines For Supplement Safety
January 1999

Although dietary supplements enjoy a stellar safety record (see our editorial Safer Than Food), some cautions do apply.

1. Almost anything, including supplements, can be toxic if one takes too much. Controversy surrounds the question of safe upper limits, more technically known as tolerable upper intake levels. (See our story on RDAs And Safe Upper Limits: Solid Science Versus Bureaucratic Bias). For most supplements, scientific information is still quite sparse concerning how much is too much.

   Most vitamins and minerals are safe at a wide range of dosage levels. Some vitamins are remarkably safe even when taken in very large quantities. However, a few minerals can be hazardous at levels only a little higher than the Recommended Dietary Allowance (RDA).

   If you take levels higher than the RDA of vitamins and minerals, be sure to consult your doctor or nutritionist. Make sure you know what levels are considered dangerous -- and learn about symptoms of overdosages. (See our links to sources of information about specific supplements.)

2. Most botanical supplements act gently on the body, but some can be quite potent. Many modern drugs (including morphine, digitalis, ephedrine and curare) are based on herbal remedies used by indigenous peoples.

   For the most part, centuries of experience has shown herbalists what dosages are safe and effective, and which plants can be hazardous. Be sure you know the potential dangers of any botanical supplements you are taking.

3. Most botanical supplements and some nutritional supplements can interact with prescription and over-the-counter drugs. Sources of information on these interactions are growing.

4. As with other substances, allergic reactions and sensitivies do exist. Check labels for substances you are allergic to.