Study of Vitamin D Found in Supplements Found Label Doesn't Match Contents

Vitamin Labels May Be Wrong by Nicholas Bakalar.  The New York Times Well Blog.  February 18, 2013.

Standards set by the United States Pharmacopeial Convention requires that pills contain 90 percent to 110 percent of the listed potency.  The study in JAMA Internal Medicine found that the vitamin D bottles samples contained between 9 percent to 140 percent.