Vitamin D has been endlessly promoted as a treatment for many diseases due to evidence from observational studies, but hundreds of millions of dollars in randomized controlled trials have never demonstrated it to be effective for any disease except rickets.
There was just a large trial published in JAMA [1] examining its effectiveness for depression given solid observational data. It was not at all effective.
The reason that Vitamin D is associated with many diseases but is not causative for anything is that Vitamin D level is highly correlated with other metrics of health such as socioeconomic status, active lifestyle, nutritional sufficiency, etc.
We are wasting our time and money looking at Vitamin D again and again and again.
There was just a large trial published in JAMA [1] examining its effectiveness for depression given solid observational data. It was not at all effective.
The reason that Vitamin D is associated with many diseases but is not causative for anything is that Vitamin D level is highly correlated with other metrics of health such as socioeconomic status, active lifestyle, nutritional sufficiency, etc.
We are wasting our time and money looking at Vitamin D again and again and again.
1. https://jamanetwork.com/journals/jama/article-abstract/27689...