A new cohort study found that both low and high vitamin D levels before hospital admission are associated with increased risk for all-cause mortality.
A number of studies have examined the effects of low vitamin D status on health outcomes and mortality. For example, a review of randomized controlled trials found a 3-7% reduction in all-cause mortality in non-hospitalized adults who were given vitamin D, compared to adults who were given a placebo.
Researchers haven’t extensively studied the effect of very high vitamin D status on health outcomes and mortality.
This lack of research is reflected by a lack of consensus among the scientific community regarding the acceptable lower and upper limits of vitamin D levels. However, a wide therapeutic window exists for vitamin D and toxicity is only associated with levels of 150 ng/ml or more.