Vitamin D is not a “miracle” and recent RCTs do not support supplementation:

For a decade now, my team has published papers and book chapters that call for an end to high-dose vitamin D supplementation. Our research indicates that the low levels of vitamin D often identified in patients with chronic inflammatory disease may be a result, rather than a cause of the disease process (eg, the concept of “deficiency” is incorrect). These two large 2018 studies support an end to vitamin D supplementation:

Effects of vitamin D supplementation on musculoskeletal health: a systematic review, meta-analysis, and trial sequential analysis

Paper highlight: “There is little justification to use vitamin D supplements to maintain or improve musculoskeletal health. This conclusion should be reflected in clinical guidelines”

Vitamin D Supplements and Prevention of Cancer and Cardiovascular Disease

First author: JoAnn Manson, Harvard University

This nationwide, randomized, placebo-controlled trial found that supplementation with vitamin D did not result in a lower incidence of invasive cancer or cardiovascular events than placebo.