Dietary Supplements
Herbs, vitamins, minerals, botanicals and other substances are regulated as dietary supplements by the FDA differently than drugs. FDA has no role before the nutritional supplement is marketed in looking at either safety or effectiveness. According to law a dietary supplement:
- Is a product (other than tobacco) intended to supplement the diet, which contains one or more of the following: vitamins; minerals; herbs or other botanicals; amino acids; or any combination of the above ingredients.
- Is intended to be taken in tablet, capsule, powder, softgel, gelcap, or liquid form.
- Is not represented for use as a conventional food or as a sole item of a meal or the diet.
- Is labeled as being a dietary supplement.
Once a supplement is on the market, the FDA can remove a product only if the agency can prove it is dangerous. The FDA also can review labeling to be sure all ingredients are listed and that the label or its advertising does not promote the supplement as more than an addition to the diet. It is illegal to label or advertise a dietary supplement as a treatment, prevention, or cure for any disease.
What’s In the Bottle
With hundreds of thousands of supplements on the market, the FDA can only deal with the most serious offenses, so consumers need to be alert. Problems that have been found with dietary supplements include:
- Dangerous interactions with prescribed and over-the-counter drugs.
- Contamination with unlabeled metals, pesticides, and other herbs.
- Unlabeled prescription drugs.
- More –or less– of labeled ingredients actually in the recommended dose.
Herbal Interactions you need to know about
- St. John’s Wort, used for mild depression in some countries, reduces the amount of the colorectal cancer drug Camptosar® (irinotecan) available in the blood by almost 50%.
- Garlic supplements, ginkgo biloba, or vitamin E may increase the risk of bleeding in patients who are taking Coumadin® (warfarin), aspirin or other blood thinners to prevent blood clots during chemotherapy. They can also increase risk of bleeding during surgery or colonoscopy.
- Kava and ephreda can raise blood pressure, sometimes to life-threatening levels. Some cancer drugs, such as Avastin® can also raise blood pressure.
- Finally, since herbal or other nutritional supplements can be marketed without proof of their effectiveness, a method may be safe, but useless and expensive.
Bottom Line
Tell your doctors about any dietary supplement or over-the-counter drug you are taking.
Where Can You Go for More Information?
Tips for the Savvy Supplement User: Making Informed Decisions and Evaluating Information developed by the Food and Drug Administration (FDA).
Medline Plus Herbs and Supplements is an alphabetical list of a wide variety of herbs and dietary supplements that provides background, dosing information, scientific evidence for effectiveness, safety information, and potential interactions with other drugs or foods.
The National Library of Medicine Dietary Supplements Labels Database provides searchable information about the ingredients in over 2,000 selected branded dietary supplements. You can search by brand, by ingredient, or by manufacturer. Information in the database is linked to Medline Plus and PubMed, also Library of Medicine internet data. The database helps consumers determine what ingredients are in specific brands and to compare ingredients in different brands. Information is also provided on the health benefits claimed by manufacturers. Warnings and recalls from the FDA are also included.
Last Update: April 13, 2008
Medical Review
This page is under review by C3's medical review network.
