There are several studies where vitamin D works (amazingly well), and one study where it does not.
But in the study where it does not work, it's an oral supplement given after hospitalization. Oral vitamin D takes a while to elevate blood levels so the fact that such regimen doesn't work, doesn't prove much.
But in the study where it does not work, it's an oral supplement given after hospitalization. Oral vitamin D takes a while to elevate blood levels so the fact that such regimen doesn't work, doesn't prove much.