The Food and Drug Administration frequently recalls dietary supplements that are found to contain banned substances. But a new study shows that many of these products return to store shelves months later with the same dangerous ingredients. The findings suggest that health authorities may be fighting an uphill battle against a small number of supplement companies that repeatedly sell contaminated products. The new study, published in JAMA, the Journal of the American Medical Association, found that out of more than two dozen supplements that were pulled from shelves
