New recommendations for daily intake of vitamin D, from the influential Institute of Medicine, hasn’t quieted the debate on how much of the vitamin children and adults really need.
The United States and Canada asked the Institute of Medicine, which is part of the National Academy of Sciences, to update the official vitamin D recommendations for the first time since 1997. A 14-member expert committee convened for the task concluded that most Americans and Canadians up to age 70 need no more than 600 international units of vitamin D per day. The elderly may need as much as 800, the committee concluded.
Previously, experts called for children and younger adults to get 200 international units a day, adults-ages 50 to 70- 400, and the elderly to get 600. The modest increase in dosage, most likely, will not be enough for people who believe a much higher dose should be recommended.
The committee was surprised to see that most Americans are meeting their needs for both of the nutrients, calcium and vitamin D, except for adolescent girls who may not be getting enough calcium and some elderly people who don't get enough of either, says Catharine Ross, professor of nutrition at Pennsylvania State University and chairwoman of the panel that prepared the report. The Institute of Medicine (IOM) is set up by Congress to advise on a variety of health issues.
Among the reasons for sufficient intakes: food fortification and more supplement use. Many foods, such as milk and yogurt products, are rich in calcium and fortified with vitamin D. Fatty fish such as salmon, mackerel and tuna also have a lot of vitamin D. Sunlight triggers the production of vitamin D in skin and contributes to people's levels.
After reviewing nearly 1,000 published studies along with testimony from scientists and others, the expert committee concluded that vitamin D and calcium play an important role in creating and maintaining strong bones. But the committee concluded that while further research was warranted into vitamin D's role in other health issues, at this point the evidence is mixed and inconclusive. The committee noted that other nutrients, such as vitamin E, were thought to have a host of health benefits, an idea that was later disproved and in some cases found to be dangerous.
The recommendations disappointed many proponents of higher vitamin D intake. Robert Heaney, a professor of medicine at Creighton University in Omaha who has studied vitamin D's health benefits, says the overall daily value of 600 IUs of vitamin D a day "is way too low." He says people should consider taking up to 4,000 IUs a day.
"For me, it's a no-brainer. There is a large body of evidence for benefit at intakes above the IOM recommendations. There is no risk, and very little cost, so why not take a chance of a benefit if there's any possibility?"
Recommendations by age:
Among the Institute of Medicine's specific recommendations for vitamin D and calcium by age group:
-- Children ages 1 to 3 should consume 700 milligrams of calcium a day; children ages 4 to 8, 1,000 milligrams of calcium daily.
-- Adolescents 9 through 18 require no more than 1,300 milligrams of calcium a day.
-- For adults ages 19-50 and men up until age 71, 1,000 milligrams of calcium meets their daily needs.
-- Women beginning at age 51 and men age 71 and older need no more than 1,200 milligrams of calcium a day.
-- Children and adults under 71, 600 IUs (international units) of vitamin D daily.
-- People 71 and older may need as much as 800 IUs a day.