[artinmg]

Why would that be interesting? Presuming the effect of limited sun exposure is posited as vitamin D deficiency, that is already an indication for supplementation, regardless of any effect on CVD risk reduction.

The purpose of a study like this would be to determine whether vitamin D supplementation is indicated for CVD prevention independent of vitamin D deficiency, which is why the study recruited from the general population, excluding only those in whom vitamin D supplementation would be contraindicated.