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Posted on 03-19-2013


Good Morning!

A research letter published in February 2013 in The Journal of the American Medical Association Internal Medicine (also known as JAMA) was picked up by many most major news outlets and showed concerns about supplements, in this case vitamin D. Researchers purchased vitamin D supplements from 12 different manufacturers and sent them off to an independent lab for testing. The results were shocking! They revealed big discrepancies - 30 percent of the results were such that the products were either too high or too low according to the U. S. Pharmacopeial Convention (USP).

Like most people, you have probably always assumed if a product says it has “x” in it, that’s what it is. For example, a one-pound bag of carrots should contain 16 ounces of carrots, , the food ingredient label must be accurate if it states that one cup equals 50 calories, and the supplement panel must be right if it says one tablet equals 1,000 international units (IU). Apparently it’s not that simple! So, what’s the story on supplements, and how can you feel safe when choosing our supplements (vitamin D or any other for that matter)?

All of our Metagenics products have a certificate of assay (COA) that goes with the “lot” of product received. Each “lot” is essentially a batch or recipe. The label on the bottle states a tablet contains 5,000 IU vitamin D.

For Vitamin D, the specification has been written that the product meets label claims if it contains as little as 900 IU or as much as 1,750 IU per tablet. While this variance might seem wide (there’s usually a bigger allowance for overages and not more than a 10 percent variance for being under the stated level), it really isn’t.

In the JAMA article, laboratory results of vitamin D contained in a single pill, tablet or capsule ranged from as little as nine percent to 140 percent – but when researchers tested five pills from each bottle and averaged the results, the levels were closer to 100 percent!

We use Metagenics as our manufacturing partner because they are an accredited lab, follow good manufacturing practices and have passed FDA audit with the highest standards. 

Going back to the JAMA study, when a batch of different Vitamin D products, or any other supplement, is pulled off the shelf for testing, I’ve come to wonder what exactly is being tested, and what specific test methodology is being used. For example, we understanding is that the test protocol doesn’t ever test just one tablet or pill – it’s a combination of multiple tablets, and in fact we always send two bottles of product from any “lot” to make sure there’s plenty of product to blend together and then sample. And, going back to the food example, I’ve also come to realize that when I buy a packaged product (carrots, shrimp, potato chips, etc.), I should assume that the calorie count is going to be a bit higher to allow for overages the manufacturer has likely included in an effort to ensure the serving size on the label claim is met.

To protect yourself, talk with your supplement supplier about where their products are manufactured, the steps they take to ensure consistency and ask to see a COA.

Have a blessed day!


Portions of this blog have been taken from coopernutrition.

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