The nation’s top scientific advisory panel recommended that adults modestly increase their intake of vitamin D, known as the “sunshine vitamin,” from a daily dose of 200 international units (IU) to 600 IU. The panel also extended the safe upper limit for adults from 2,000 IU to 4,000 IU daily.
The Institute of Medicine (IOM) report was released November 30 in Washington, DC, after two years of study and debate. The IOM had not changed its dietary guidelines for vitamin D since 1997.
During the last 13 years, though, some studies had suggested that much higher doses of vitamin D could prevent a variety of illnesses, from bone diseases to strokes and cancer. But the IOM panel said that although more vitamin D is beneficial to bone health, other studies were inconsistent and inconclusive, and therefore taking mega doses over a long period of time might harm some people. Getting too much calcium from dietary supplements has been associated with kidney stones, the panel noted.
For Vitamin D, the IOM recommended:
- Everyone ages 1 to 70 should take 600 IU daily.
- Adults older than 70 should take 800 IU daily to optimize bone health.
- The safe upper limit for infants up to 6 months is 1,000 IU daily.
- The safe upper limit for infants 6 to 12 months is 1,500 IU daily.
- The safe upper limit for children 1 to 3 years old is 2,500 IU daily.
- The safe upper limit for children 4 to 8 years old is 3,000 IU daily.
- The safe upper limit for everyone older than 8 is 4,000 IU daily.
“The good news is that the IOM recognized that the amount of vitamin D recommended in 1997 was inadequate,” said Dr. Michael Holick of Boston University, a leading expert on vitamin D and author of The Vitamin D Solution (Hudson Street Press, 2010).
Holick said the IOM levels are at 60 percent of what he recommends. “What is needed now is more randomized controlled trials to convince them,” he said.
Dr. Andrew Shao, senior vice president scientific and regulatory affairs, the Council for Responsible Nutrition (CRN), agreed with Holick that the new recommendations are “a modest step in the right direction. While the new recommendations will benefit the public overall, there is significant scientific evidence demonstrating a potential need for vitamin D intake at levels up to 2,000 IU daily for adults to maintain optimal blood levels ranging between 30 and 45ng/mL.”
The issue of vitamin D toxicity by the IOM is “curious,” said Holick, who noted the panel deemed one study as not strong enough to support the use of high levels of vitamin D to decrease the incidence of cancer, but used the same data to defend its opinion on the possibility of high levels of vitamin D increasing incidence of pancreatic and prostate cancer.
The IOM’s RDAs for calcium varied more widely by age group and gender: children ages 1 through 3 years should receive 700mg of calcium per day; children ages 4 through 8 years should receive 1,000mg per day; adolescents need 1,300mg per day; women ages 19 through 50 and men as old as 70 need 1,000mg daily; and women 51 and older and men 71 and older need 1,200mg per day. ULs for calcium ranged from 1,000 IUs in infants to 3,000 IUs in adolescents and teenagers.
Despite the committee’s findings that the majority of people in North America receive adequate levels of calcium and vitamin D, the panel said supplementation still is appropriate from some groups, including calcium for girls ages 9 to 18 years and older women.
News headlines varied greatly on their interpretations of the report. The New York Times carried on its front page an article by Gina Kolata headlined “Extra vitamin D and Calcium Aren’t Necessary, Report Says.” The same day’s Wall Street Journal headline read “Triple That Vitamin D Intake, Panel Prescribes.”
To view original article: Vitamin Retailer January 2011