Supplements are big business. Sales today exceed $3.5 billion a year. This is an important point to keep in mind when considering if, when and how you might add supplements to your diet.

Another point to remember is that supplements are not a substitute for food. Every day new compounds in food are being discovered. Plus, we still do not know how many known compounds work in the human body. We are far from knowing all there is to know about food.

By eating a variety of foods in sensible portions, you can get all the nutrients needed for good health.

Should You Take A Vitamin Or Mineral Supplement? There are some instances where supplementation may be recommended in addition to sensible eating. Following are some of those instances. They came from the American Institute of Nutrition and the American Society for Clinical Nutrition.

Women with excessive bleeding during menstruation may need to supplement with iron.

Individuals on a very low calorie diet (less than 1200 calories for women, less than 1500 calories for men) may need a multivitamin.

Some vegetarians may need extra calcium, iron, zinc, or vitamin B-12.

Certain medical conditions such as fat-malabsorption syndrome, or osteoporosis may need supplementation.

Certain medications require supplementation such as the diuretic thiazide which requires taking extra vitamin K. Discuss any concerns over medications with your doctor.

Women trying to get pregnant may need folate because lack of folate increases risk of certain birth defects.

If you do take supplements, let your doctor know.

Which Supplement Should You Choose?

Here are some guidelines from the Council on Scientific Affairs of the American Medical Association.

• Supplements should contain no more than 50-150% of the adult daily values listed under the Nutrition Facts portion of the supplement label.
• If there is no daily value listed for that compound, then it should contain no more than 50-150% of the estimated safe and adequate daily intake (ESADDI) listed under the Nutrition Facts portion of the supplement label. These are compounds that do not have a daily value yet established.
• Supplements should not have any biotin or pantothenic acid. Deficiencies in these compounds are very rare, so supplementation is unnecessary.
• Supplements should not have any PABA (para-amino benzoic acid), hesperidin complex, inositol, bee pollen, or lecithin. The body does not need these compounds and there are no proven benefits from taking them.
• Potential Problems When Taking Supplements The following vitamins and minerals, when taken in excess can, cause serious side effects.
• Vitamin C greater than 1 gm (1000mg) can cause diarrhea, pain in the intestines, inhibition of copper absorption, and incorrect diagnostic tests.
• Zinc greater than 30 mg can inhibit copper and iron absorption.
• Folate greater than 1 mg can mask signs and symptoms of vitamin B-12 deficiency. In larger amounts it can inhibit the action of anticonvulsants.
• Vitamin A greater than 6,000 retinol equivalents can cause gastrointestinal problems, headaches, blurred visions, hair loss, liver toxicity, and even death.
• Vitamin D greater than 25 microgram can cause weakness, nausea, diarrhea, vomiting, mental confusion, and in children mental retardation.
• Vitamin E greater than 1000 mg can cause problems in clotting blood, headaches, nausea, double vision, and muscle weakness.
• Selenium greater than 850 microgram can cause hair loss, nail changes, garlic-like breath, nausea, diarrhea, and abdominal pain.
• Beta carotene greater than 20 mg can turn your skin yellow.
• Taking large amounts of vitamins and minerals does not mean you will have better health.

Regulation Of Supplements

The Federal Drug Administration (FDA) does not regulate a supplement unless it has evidence that consumption will cause grave danger and/or that the manufacturer is making illegal claims. Therefore, don't assume only safe supplements are sold over the counter.

Advertising, including packaging, can not make claims about food or supplements curing or preventing a disease unless solid scientific evidence exists to back up such claims. This is why there are rarely claims written on supplement bottles.

Very few health claims based on food supplements have any research supporting them. There is a particular lack of validating research published in reputable scientific journals. Instead, claims are made by supplement manufacturers in brochures, magazines and pamphlets placed near the supplements in a store.

In addition there are potential risks in taking supplements. Since there are no regulations on what a supplement contains, a supplement may contain substances other than what the label states. Thus, one risk is of consuming a contaminated product. Another risk is for individuals with allergies who may have an allergic reaction to unlisted substances contained in food supplements. People with known allergies need to take extra precautions before consuming food supplements.

Any adverse or allergic reactions to supplements should be reported to the Federal Drug Administration (FDA). Their fax number is 1-800-FDA-0178."

Bottom Line

Supplements can benefit some people, if used properly. There are many instances where supplements may be appropriate.

However, before taking any food supplements it is in your best interest to consult your doctor.

Food supplements may interact with medications. Food supplements may compromise a medical condition. The exact and appropriate dosage for you needs to be determined. These are all issues your doctor can address.

References:

Barrett, SB, Herbert, JD. The Vitamin Pushers: How the "health food" industry is selling America a bill of goods. Prometheus Books, 1994.

Wardlaw, GM, Insel, PM. Perspectives In Nutrition. Mosby, 1995.

Hudnall, M. Vitamins, Minerals and Food Supplements. Chronimed Publishing, 1996.

5/28/98

Teresa Pangan is a registered dietitian with a consulting business called Nutrition Visions. She conducts wellness and nutrition programs and writes for various publications. She is also finishing her doctorate in nutrition at Texas Woman's University.