Dietary Supplements: Quality Matters

Dietary supplement is regulatory term. By definition, dietary supplements include vitamins, minerals, herbs, botanicals, fatty acids, and amino acids as long as they are prescribed in dosage forms, such as capsules, tablets, liquids, gels or powders. The FDA regulates dietary supplements based on 1994 Congressional legislation referred to as DSHEA (Dietary Supplement Health Education Act).While the consumer is guaranteed access to a variety of supplements by the current legislation, and guaranteed access to promotional literature and dosage suggestions, quality of dietary supplements is not assured in the U.S. It should be a given that what is on the label is in the bottle, but there is extensive published documentation of subpotent products, contamination of products with heavy metals, pesticides, herbicides, aftlatoxin, bacteria, PCBs and dioxin. There are many instances of adulteration of a product, often likely a function of inadvertent misidentification of an herb, such that the herb in the bottle is not the herb on the label. One example of this is skullcap, listed in the Consumer Reports dirty dozen, even though the published literature indicates that the liver toxicity of the skullcap product was due to mislabeling of germander, which is known to be toxic to the liver.

Due to lack of government regulation of dietary supplement quality, the consumer who shops price alone is likely to purchase an inferior quality product, or worse, an adulterated or contaminated product. Fortunately, there are methods for the consumer to determine the quality of a dietary supplement. Consumerlab is a business which purchases a variety of brands of popular dietary supplements off the shelves of health food stores and pharmacies, analyzes these independently for quality, and posts the results on its web site, www.consumerlab.com. There is an annual subscription of $30 to subscribe to the information posted on the site. In addition to Consumerlab, there are businesses which certify manufacturers of dietary supplements for Good Manufacturing Practices. Certification of manufacturing is available through NSF, NNFA, and USP - web sites which list companies which are certified are www.uspverified.com, www.nsf.org/certified/dietary and www.nnfa.org/services/science/gmp. Beware though that even if a company is certified by NSF or NNFA or USP, this information is not necessarily included on the product label. Beware also that NNFA and NSF certifications address only the chemical composition, not the bioavailability of the herb. USP and Consumerlab do address bioavailability as well as chemical composition.

UPDATE in 2007: NNFA has changed its name to the Natural Products Association (NPA), and while the above web site link is still functional, the new link is http://www.naturalproductsassoc.org/site/PageServer?pagename=ic_gmp_cos. The FDA on 6/22/07 announced a final rule establishing regulations to require current good manufacturing practices (cGMP) for dietary supplements. The rule ensures that dietary supplements are produced in a quality manner, do not contain contaminants or impurities, and are accurately labeled. The establishment of cGMP for dietary supplements was required by DSHEA, passed by Congress in 1994. The announcement of this is posted at http://www.fda.gov/bbs/topics/NEWS/2007/NEW01657.html. The final cGMP and the interim final rule became effective October 24, 2007. To limit any disruption for dietary supplements produced by small businesses, the rule has a three-year phase-in for small businesses. Companies with more than 500 employees have until June 2008 to comply, companies with less than 500 employees have until June 2009 to comply, and companies with fewer than 20 employees have until June 2010 to comply with the regulations. The final rule itself, 814 pages, as published in the Federal Register, is posted at http://www.fda.gov/OHRMS/DOCKETS/98fr/cf0441.pdf. Some experts have identified concerns with the comprehensiveness of the final rule - two critiques are published in Integrative Medicine: A Clinician's Journal (IMCJ. 2007. 6[5]. 8-9 and 28-31).

[Last updated November 24, 2007] [Return to Home Page]