IOM Revises Vitamin D, Calcium DRIs
The Institute of Medicine (IOM) has issued a report revising the dietary reference intakes (DRIs) for vitamin D and calcium, while warning that “too much of these nutrients may be harmful.” At the request of the U.S. and Canadian governments, the IOM Food and Nutrition Board assessed more than 1,000 vitamin D and calcium studies related to a range of health outcomes, “including but not limited to cancer, cardiovascular disease and hypertension, diabetes and metabolic syndrome, falls, immune response, neuropsychological functioning, physical performance, preeclampsia, and reproductive outcomes.” Although evidence apparently substantiated “the importance of vitamin D and calcium in promoting bone growth and maintenance,” it did not confirm any “benefits beyond bone health—benefits often reported in the media.”
The new DRIs provide nutrient guidelines based on estimated average
requirements, recommended dietary allowances and upper level intakes for
different age groups. According to IOM, “Most Americans and Canadians up to
age 70 need no more than 600 international units (IUs) of vitamin D per day
to maintain health, and those 71 and older may need as much as 800 IUs.” In
addition, “The amount of calcium needed ranges, based on age, from 700 to
1,300 milligrams per day.”
The IOM findings note that most people receive enough vitamin D and
calcium from dietary or environmental sources to maintain good bone health.
It also cautions against consuming high amounts of these nutrients, which
are often included in popular supplements and fortified foods. “Kidney stones
have been associated with taking too much calcium from dietary supplements,”
states the IOM report. “Very high levels of vitamin D (above 10,000
IUs per day) are known to cause kidney and tissue damage. Strong evidence
about possible risks for daily vitamin D at lower levels of intake is limited, but
some preliminary studies offer tentative signals about adverse health effects.”
See IOM Press Release, November 30, 2010.
Meanwhile, the Vitamin D Council has lambasted the IOM’s conclusions, questioning how the board could recommend the same vitamin dose for infants, adults and pregnant women. “While that 400 IU/day dose is close to adequate for infants, 600 IU/day in pregnant women will do nothing to help the three childhood epidemics most closely associated with gestational and early childhood vitamin D deficiencies: asthma, auto-immune disorders, and, as recently reported in the largest pediatric journal in the world, autism,” opines a December 1, 2010, press release.
The group has since filed a Freedom of Information (FOI) request asking IOM to release 14 consultation reports allegedly suppressed during the review process. It also accuses the Food and Nutrition Board (FNB) of ignoring “thousands of studies from the last ten years that showed higher doses of vitamin D helps: heart health, brain health, breast health, prostate health, pancreatic health, muscle health, nerve health, eye health, immune health, colon health, liver health, mood health, skin health, and especially fetal health.”
“Today, the FNB has failed millions of pregnant women whose as yet unborn babies will pay the price,” concludes the council’s statement, which advises pregnant women to “continue taking 5,000 IU/day until their [5-hydroxy vitamin D blood test] is between 50–80 ng/mL (the vitamin D blood levels obtained by humans who live and work in the sun and the mid-point of the current reference ranges at all American laboratories).” See The New York Times, November 19, 2010.
