Most recently, a NEJM paper “Vitamin D Deficiency — Is There Really a Pandemic?” by Manson, Brannon, Rosen, and Taylor explains the big misunderstandings that let some authors conclude that whole populations are being vitamin D deficient. Just to recall, the IOM recommended in 2010 serum concentrations of vitamin D (i.e., 25-hydroxyvitamin D [25(OH)D]) above 20 ng per milliliter (or 50 nmol per liter) as appropriate level and supplementation with 600 to 800 IU per day as Recommended Dietary Allowance (RDA). And here are the 8 facts: Continue reading The end of the vitamin D deficiency debate? 8 facts →