Recommended-daily-vitamin

Recommended-daily-vitamin

Vitamin D deficiency has become something of a health bugaboo in recent years, especially after a 2009 study that declared three quarters of U.S. adults and teenagers deficient. Low levels of the vitamin—which is manufactured by the body when sunlight hits the skin and can be found in some fatty fish and fortified food products—have been linked to disparate conditions, such as a sluggish immune system and psychosis.

But a new report from the Institutes of Medicine (IOM), released November 30, concludes that the evidence linking vitamin D and calcium deficiency to anything but poor bone health is inconclusive. It also determined that most people in the U.S. and Canada are getting ample amounts of the vitamin. Even so, the organization is raising the level of recommended daily intake.

The new assessment recommends a daily vitamin D dietary allowance of 600 milligrams for most healthy people 9 years and older (with an estimated average requirement of 400 International Units per day—and no more than 4,000 IU of vitamin D per day). People 71 years and older should take 800 mg of the vitamin per day, according to the report. (Children aged 4 to 8 years should not have more than 3,000 IU/day and those aged 1 to 3 years should not have more than 2,500 IU/day.)

The updated daily recommendations are not directly comparable to previous sets, which were established in 1997 and are based on “adequate intakes” rather than on the newer recommended dietary allowance and estimate average requirement. Catharine Ross, chair of the IOM’s review committee and a professor of nutrition at Pennsylvania State University, noted in a Tuesday press briefing that the two values are “like comparing apples to pears.” (The previous adequate intake recommendations were 200 IU per day for infants through age 50, 400 IU/day for ages 51 to 70, and 600 IU/day for those 71 and older.)

Adequate intake was more of “a guesstimate,” Patsy Brannon, a professor of nutritional sciences at Cornell University and member of the IOM review committee, said at the briefing. Those who did not meet the previous adequate intake levels were at a higher risk for deficiency, but “you cannot assume that individuals are deficient if they do not meet the adequate intake,” she explained.

That the IOM is “recognizing that their 1997 recommendations are too low” is substantial progress, says David Hanley, a professor in the departments of Medicine, Community Health Sciences and Oncology at the University of Calgary, who was not involved in the new report.

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