Low blood levels of Vitamin D is highly correlated with just about every disease known to mankind.
Yet, studies repeatedly have shown that Vitamin D supplementation has next to no benefit in curing those diseases.
So either there's a jointly correlated third factor like sun exposure or low Vitamin D levels are CAUSED by those diseases and in general just an indicator of overall poor health.
Low blood levels of Vitamin D is highly correlated with just about every disease known to mankind.
Yet, studies repeatedly have shown that Vitamin D supplementation has next to no benefit in curing those diseases.
So either there's a jointly correlated third factor like sun exposure or low Vitamin D levels are CAUSED by those diseases and in general just an indicator of overall poor health.