ConsumerLab.com is an independent lab that tests dietary supplements for qualities such as strength, purity, identity, and disintegration. You have to pay for their reports. I think it’s about $36 a year for a subscription. But they tease results on their site and even just those reveal a very sloppy, and sometimes dangerous dietary supplement business.

Here’s a summary of their review of multivitamins updated May 2014. They tested 75 products, from the high-end TwinLab, Life Extension, and Garden of Life, to the more common Centrum and One-A-Day, to private labels including GNC, Trader Joe’s, Whole Foods, Vitamin Shoppe, Walgreens, and even some pet vitamins.

Product Review: Multivitamin and Multimineral Supplements Review

ConsumerLab.com found defects in nearly 40% of multivitamins it selected for testing. Here are some of the discoveries:

• One popular general multivitamin contained nearly 2.5 times its claimed amount of vitamin A in the retinol form. Too much of this type of vitamin A can be harmful.
• 12 multivitamins provided less vitamin A, vitamin C, or folate, or than claimed, some with less than 30% of the listed amounts. These include a prenatal vitamin and products for men, adults (general), seniors, and even pets.
• Tablets of a women’s multi and a general adult multi failed to break apart within the required time — indicating they may not fully release all of their ingredients for absorption.
• One pet multivitamin was contaminated with lead.
• A range of multivitamins contained more than the upper tolerable limits of niacin, vitamin A, magnesium, and/or zinc.

The FDA doesn’t do pre-market testing, but it does require the manufacturer to do it:

Dietary Supplement Current Good Manufacturing Practices (CGMPs) and Interim Final Rule (IFR) Facts, FDA, 22 June 2007, Last Updated 19 September 2014

The rule establishes CGMPs for industry-wide use that are necessary to require that dietary supplements are manufactured consistently as to identity, purity, strength, and composition.

For Consumers: Final Rule Promotes Safe Use of Dietary Supplements, FDA, 22 June 2007, Last updated 14 October 2014

The final rule aims to ensure that dietary supplements do NOT have:

• wrong ingredients
• too much or too little of a dietary ingredient
• improper packaging
• improper labeling
• contamination problems due to natural toxins, bacteria, pesticides, glass, lead, or other substances

I don’t understand how manufacturers get away with it.

Related:
– Supplements Lie, And The FDA’s Hands Are Tied
– An old post of mine, same issue: The Truth About Supplements, May 2007. It looks like sales of dietary supplements have grown from $21 billion in 2006 to $61 billion in 2014.