Supplements: More truth in labels; no big help
The U.S. Food and Drug Administration has finalized new labeling requirements for dietary supplements, just as the consumer craze for vitamins and minerals in a bottle has peaked. But while you’ll be able to interpret the labels more easily, the real challenge will be in counseling patients who take supplements.
The National Institutes of Health (NIH) established its Office of Dietary Supplements just two years ago and has seen consumer spending on supplements double, from $3 billion in 1990 to more than $6.5 billion on the more than 1,000 supplements on the market in 1996. As supplement use explodes, pharmacists are challenged to translate the new labels, field questions from patients, and make sure the supplements don’t pose a risk within the patient’s overall drug therapy.
"Consumers are being bombarded with a lot of information in the media and look to a professional to interpret that information. The first line of defense is often the pharmacist," says Mary Burnette of Council for Responsible Nutrition in Washington, DC. "I think consumers getting prescriptions assume that since a doctor prescribed a given drug, it’s OK to take. But with the dietary supplements, they have a lot of questions. The problem is pharmacists have a long way to go in educating themselves about these sorts of things."
And why shouldn’t consumers be confused? Even pharmacists have trouble sorting out the conflicting studies popping up more frequently now that the use of supplements is attracting media and regulatory attention. Take, for example, beta carotene, which was touted as an easy way to reduce risk of cancer. A recent study showed that heavy smokers taking beta carotene were contracting the disease in higher numbers than heavy smokers not taking the supplement.
Dosages are another area of concern, as consumers often believe that two vitamin E pills will make them healthier than one. Are pharmacists able to tell consumers that high doses of vitamin E can interfere with the body’s vitamin K, which promotes blood clotting? Or that high doses of calcium can limit the absorption of iron? Or that too much zinc can impair the immune system? "The worry is patients taking supplements in relation to their prescribed medicine, and the adverse reactions it could cause," says Steven Cano, PharmD, director of pharmacy at Fallon Healthcare Systems in Worcester, MA. "Clearly, supplements can have an impact on drug therapy, but we’re not asking those questions and we should be in the hospital settings."
When Cano cautions about adverse reactions between supplements and prescription drugs, he’s not alone. And unlike standard vitamins historically used by Americans, the newer and more exotic dietary supplements have no regulatory dosage or recommended amounts that should be taken based on clinical studies.
"It’s essentially a buyer beware marketplace," says William Jarvis, PhD, president of the National Council Against Health Fraud in Loma Linda, CA. He blames the 1994 federal Dietary Supplement Act for not requiring dosage or reaction information. "All we have is the FDA trying to put forth good manufacturing practices, and that’s the basement level of this kind of need. The people who know what’s in these things are the manufacturers, and they don’t have to tell us."
Along with Jarvis’ council, NIH’s Office of Dietary Supplements and Office of Alternative Medicine, the U.S. Department of Agriculture, and the FDA-run Food and Nutrition Institute also can’t say what the recommended dosages of dietary supplements may be or what adverse reactions are out there in terms of prescription drugs.
Without required studies by their makers, those studies aren’t being done, though several of the above agencies say they are working on just that type of information database. The National Academy of Sciences adopted the Recommended Daily Allowance (RDA) for basic household vitamins during World War II for soldiers in the field, Jarvis says, and that agency is not pursuing any similar information for the newer dietary supplements.
With little oversight of the production or marketing of dietary supplements FDA approval is only required if a dietary supplement makes medical claims the federal Dietary Supplement Health and Education Act of 1994 did find a way for the FDA to get involved, by requiring more nutritional detail and ingredient values for the jargon touted on the labels. For example, the label requirements set limits on the use of terms such as "high in antioxidants" or "high potency." The new labeling requirements limit the use of antioxidants to vitamins or minerals known to protect against free-radical damage. The term "high potency" can be used only for a single-ingredient supplement containing at least 100% of the vitamin’s daily value. The FDA also allows the term "high potency" in multi-ingredient products when two-thirds of the daily value nutrients also are present at 100% of the daily value or greater.
In the face of concerns that Americans are gulping down too much or too many supplements, John Hathcock, MD, a former FDA director and the current director of Nutrition and Regulatory Science at the Council for Responsible Nutrition, argues that people should be taking more doses than the RDA. "Substantial evidence indicates that intakes greater than the RDAs of certain vitamins and minerals such as calcium, folic acid, Vitamin E, selenium, and chromium reduce the risk of certain disease for some people. The margin of safety between the usual dietary intake and the intake that would produce adverse effects varies greatly among the different nutrients," he says.
Hathcock details his scientific argument in a 10-page article, "Vitamins and minerals: efficacy and safety" (Am J Clin Nutr 1997; 66:427-437), by referencing 152 journal studies, clinical trials, and government records on the subject.
The article notes that although "very high" intakes of vitamins A and D, along with niacin, pyridoxine, and selenium, for example, have produced adverse effects, claims that vitamins C and E and trivalent chromium also carry adverse effects "have little factual basis." Hathcock attempts to shed some light on beta carotene by noting that there is no evidence of its adverse effects except in "current heavy smokers."
He summarizes current literature and science on vitamins and minerals including calcium, folic acid, beta carotene, nicotinic acid, pyridoxine, selenium, chromium, and vitamins E, C, and A, pointing out the known risks and myths. His central thesis, that "evidence is rapidly accumulating that intakes above the RDA for some micronutrients provide benefits in reducing the risk of chronic disease," is accompanied by dosage examples. Calcium, he argues, is beneficial at doses of 1000 to 2000 mg, while the RDA is set at 800 mg.
Arguments like Hathcock’s, coupled with new supplement labeling and a growing consumer appetite, give pharmacists yet another challenge to, uh, digest.
[For more information, contact Mary Burnette or John Hathcock at the Council for Responsible Nutrition, 1300 19th St. NW, Washington, DC 20036. Telephone: (202) 872-1488. World Wide Web: http://www.crnusa.org.
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