I've heard that vitamins sold at grocery stores (as opposed to health food stores) are only partially absorbed by your body. Is this true?

The theory that vitamins from health stores are better is false. Because vitamins are not regulated by the FDA, no one checks to make sure that they contain what their bottles claim they contain (or that they are absorbable, etc.). As a result, there can be a wide variance between any type of vitamin - grocery store or health food store. The best thing to do is research the particular vitamin you're taking, and find out more about its makeup. Consumer Labs is a good resource because it independently tests all types of products. They test many multivitamin supplements for purity, bioavailability (how readily they’re absorbed), contaminants, and vitamin content. They list vitamins that pass their tests, and you can see that some of the grocery store brands are on the good list (Centrum, Puritan's Pride, etc). Although you must subscribe to get a complete listing, Consumer Labs gives a good example of the variability in supplements—and proves that where they're purchased makes no difference.

For more information on purchasing vitamins and supplements see the following articles from TheDietChannel: How to Protect Yourself When Purchasing Supplements and Nutrition Quackery.

Erin Dummert RD, CD Contributing Expert

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