https://www.ncbi.nlm.nih.gov/pubmed/28768407
The Big Vitamin D Mistake.
Since 2006, type 1 diabetes in Finland has plateaued and then decreased after the authorities' decision to fortify dietary milk products with cholecalciferol. The role of vitamin D in innate and adaptive immunity is critical. A statistical error in the estimation of the recommended dietary allowance (RDA) for vitamin D was recently discovered; in a correct analysis of the data used by the Institute of Medicine, it was found that 8895 IU/d was needed for 97.5% of individuals to achieve values ≥50 nmol/L. Another study confirmed that 6201 IU/d was needed to achieve 75 nmol/L and 9122 IU/d was needed to reach 100 nmol/L. The largest meta-analysis ever conducted of studies published between 1966 and 2013 showed that 25-hydroxyvitamin D levels <75 nmol/L may be too low for safety and associated with higher all-cause mortality, demolishing the previously presumed U-shape curve of mortality associated with vitamin D levels. Since all-disease mortality is reduced to 1.0 with serum vitamin D levels ≥100 nmol/L, we call public health authorities to consider designating as the RDA at least three-fourths of the levels proposed by the Endocrine Society Expert Committee as safe upper tolerable daily intake doses. This could lead to a recommendation of 1000 IU for children <1 year on enriched formula and 1500 IU for breastfed children older than 6 months, 3000 IU for children >1 year of age, and around 8000 IU for young adults and thereafter. Actions are urgently needed to protect the global population from vitamin D deficiency.
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https://www.reddit.com/r/Nootropics/...tical_error_in
This is a much more readable account
http://blogs.creighton.edu/heaney/20...for-vitamin-d/
(2014) saw an unusual event. Two statisticians at the University of Alberta in Edmonton, Canada (Paul Veugelers and JP Ekwaru) published a paper in the online journal Nutrients (6(10):4472-5) showing that the Institute of Medicine (IOM) had made a serious calculation error in its recommended dietary allowance (RDA) for vitamin D. Immediately, other statisticians checked the Canadians’ analyses and found that, indeed, they were right. Together with my colleagues at Grassroots Health, I went back to square one, starting with a different population entirely, and came to exactly the same conclusion. The true RDA for vitamin D was about 10 times higher than the IOM had said.
Basically, you need 10x more vitamin D than we thought in the past.