Researchers are suggesting that what's contained on a vitamin supplement label may not actually be what's in the bottle. During testing, they found vitamin D pills sold in stores contained anywhere from 9% to 140% of the doses listed on labels. They say effective treatment of a deficiency could be hampered but none of the pills was likely to be dangerous. The study was conducted at the Kaiser Permanente Center for Health Research in Portland, Oregon. The research is published in "JAMA Internal Medicine."