We need more vitamin D than previously believed—lots more, according to two teams of researchers.
Researchers from Canada and the U.S. charge that the National Academy of Sciences (NAS) and the Institute of Medicine (IOM), the entities that set the official Recommended Dietary Allowances (RDA), messed up the math when they ran the numbers for vitamin D. The researchers believe people should actually consume ten times more vitamin D every day than current RDA suggests.
A Canadian research team reviewed each of the 10 studies the IOM used to arrive at their RDA and their calculations revealed that 600 IU of vitamin D each day, the current RDA, puts only half the amount that they assumed in the blood. A team of American researchers wrote a letter supporting the Canadian researchers’ findings. The Canadian review and the American letter both appeared in the journal Nutrients. The Canadian medical news site Chealth noted the researchers' claims.
"The error has broad implications for public health regarding disease prevention and achieving the stated goal of ensuring that the whole population has enough vitamin D to maintain bone health," Dr. Cederic Garland, adjunct professor at University of California, San Diego, wrote in the letter. He and his team called for the NAS and the IOM to designate an RDA of 7,000 IU from all sources.
Earlier this year, results of a year-long study questioning the ability of vitamin D to protect bones caused a buzz. Wonder if the results would be the same if participants received ten times more D?