Dose response
In a webcast this week (March 29), researchers used a recent federal report to start a conversation on vitamin D. How much is enough, and how much is too much? The hour-long panel was sponsored by The Forum at Harvard School of Public Health (HSPH) and moderated by Reuters Health executive editor Ivan Oransky. It is part of the Andelot Series on Current Science Controversies. Vitamin D dosage certainly counts as a controversial subject — and the four panelists were divided evenly. On one side of the issue is a long-awaited report by the Institute of Medicine (IOM) on new “dietary reference intake” recommendations for both vitamin D and calcium, which are nutrients associated with bone health. The report maintained that most residents of North America need no more than 600 international units (IU) of vitamin D a day (800 for those over age 70) — and that most are already getting what...