Use of dietary supplements by patients in a family practice clinic

Many Americans are using alternative medical therapies as well as nutritional or dietary supplements that include vitamins, minerals, herbal products, tissue extracts, protein solutions, and other chemicals. Potential for both good and harm exists in taking many of these preparations.

We surveyed 200 consecutive patients older than 18 years attending a family practice clinic. In addition to demographic data, we asked them about their intake of dietary supplements during the past year, perceived benefits from supplements, source of information, estimated cost of products, and whether their physician knew that they were taking the product.

Fifty-two percent of the patients had taken 1 or more supplements during the past year, 18 percent used 2 to 5 supplements, and 3 percent took 6 to 13 different dietary supplements. Twenty-nine percent took them for diet and energy enhancement, and 24 percent for cancer prevention and immune system enhancement. The media was the principal source of patient information. Thirty-three percent of patients had not told their physician of their supplement use. The average estimated expenditure was $ 6.60 per month with a maximum of $ 68.90 per month. Eighty-two percent of the supplements taken were vitamins and minerals at recommended daily allowances (RDAs), whereas 18 percent were other supplements such as herbal products, megadose vitamins, and protein and amino acid preparations. Demographically, only educational level correlated significantly with supplement consumption. Patients with a high school education took significantly fewer supplements than those with more advanced education.

Physicians should have a dialogue with their patients about dietary supplements because their use is widespread. Whereas many supplements are taken in safe doses, for others neither safety nor effectiveness has been proven, and for a few there are known toxicities. Additional research is needed to investigate both the safety and effectiveness of these products.