Millions May Be Taking Vitamin D Unnecessarily, PLOS ONE Reveals

Nearly 80 million Americans would no longer need to take vitamin D supplements under new Institute of Medicine guidelines, according to a study by Loyola University Chicago Stritch School of Medicine researchers. Results were published Oct. 24, 2012 in the journal PLOS ONE. The new guidelines advise that almost all people get sufficient vitamin D when their blood levels are at or above 20 nanograms per milliliter (ng/ml). Older guidelines said people needed vitamin D levels above 30 ng/ml.