> "Remember, this RDA is for bone health only," Gallagher cautioned. "It may be different for other diseases. Although trials looking into cancer, diabetes, and other diseases are ongoing, we do not have information about this yet."
"The participants were randomized to one of seven vitamin D3 doses: 400, 800, 1600, 2400, 3200, 4000, 4800 IU/day or placebo, for 1 year, and all the women were given calcium supplements to maintain a total calcium intake."
I did. The earlier study cited recommended the RDA should be 800, this study recommends 400; that cuts it by half from the earlier study.
The actual government issued RDA, now and at the time of the study, however, is 600, not 800, so it's only recommending the actual RDA be reduced by 1/3, not 1/2.
"After re-measurement of vitamin D by improved technology, the Recommended Dietary Allowance (RDA) for vitamin D intake drops from 800 to 400 International Units (IU) per day, new research reports."
https://www.sciencedaily.com/releases/2017/04/170403083103.h...