“In these nursing home veterans, vitamin D supplement users were the most frail but with high 25 (OH) D. This can potentially be a cause of U-shaped associations between vitamin D levels and negative health outcomes.”
“One of the recent controversies in vitamin D research is a “U-shaped association”, [7–9] in which both high and low levels of vitamin D are associated with elevated disease risks [7]. Regarding all-cause mortality, most observational population-based studies have shown that low vitamin D predicted premature death, which is supported by recent meta-analyses [10–13]. However, there were a considerable number of studies that showed U-shaped or reverse J-shaped associations between vitamin D and mortality [14–20].”
Vitamin D supplementation as a potential cause of U-shaped associations between vitamin D levels and negative health outcomes: a decision tree analysis for risk of frailty
A recent controversy in vitamin D research is a “U-shaped association”, with elevated disease risks at both high and low 25-hydroxyvitamin D (25 (OH) D) levels.This is a cross-sectional study of 238 male nursing home veterans in Hawaii. ...www.ncbi.nlm.nih.gov
So do you think the supplement form is risky? Is 1000IU a day safe just to avoid deficiency of vitamin D? Or is it better to do 1000IU, every other day?