Dietary Supplements Demystified

What do you think about dietary supplements?  Do you use them? Do you find them helpful? Are you confused about choosing a high quality product?

On Friday, November 8th I was interviewed by Science Friday on the topic Navigating Dietary Supplements.  There were many excellent questions raised about the quality of products, the need for further regulation by the FDA, the evidence for herbs and the need for further research.    (If you would like to learn more about the challenges of bar coding as a method for assessing dietary supplements you can read this excellent article.)  I answered many of these questions on the segment; here I’d like to make available some of the resources that I find most useful.

One of the resources that people can use to find safer, better products is consumer lab.  They are a third party company that pulls products from the shelves and tests them.   While they charge an annual fee, the price may be well worth avoiding poorer quality products.

Consumers can also feel more confident when products have a USP or NSF label on them.  Both the United States Pharmacopeia and the National Sanitation Foundation have quality verification programs.

Health professionals who want to learn more about dietary supplements may wish to purchase a subscription to the Natural Medicine Comprehensive database.  This is a resource that I find very useful in my clinical practice.  It covers the evidence for the dietary supplement, the risks (including interactions with drugs or lab studies) and usual doses.

Other free databases that can be used include:

Choosing dietary supplements can be difficult.  Especially if you have a chronic medical problem or if you are taking prescription medications you may want to obtain advice from a physician or pharmacist.  Drug-herb interactions can occur; you could inadvertently reduce the effectiveness or raise the blood levels of your prescription medication.  For example, St Johns wort, a popular dietary supplement used to treat depression can activate the cytochrome P450 system in your liver.  This revs up your liver metabolism and can  lower the blood levels of many medications – including birth control pills and HIV medications.

Overall, I believe that dietary supplements are of value for self care and for treating some medical problems.  Do your research before you get to the health food store or consult with an integrative physician, naturopath, or pharmacist.