Response to Letter Regarding Article, “Vitamin D Promotes Vascular Regeneration”

We thank Dr Kain for her interest in our work.1 Her letter puts our study into a larger population-based perspective and raises the general issue of whether vitamin D3 deficiency should be prevented by dietary supplementation or sunlight exposure. We agree with her statement that moderate sunlight exposure is probably not harmful. That avoiding sunlight is associated with increased mortality, however, is only a coincidental finding of unclear causality. Obviously, mood, mobility, physical activity, and other factors affect this association. We agree with Dr Kain’s statement that outdoor physical activity particularly exerts protective effects on the cardiovascular system at large, which extend far beyond the increased production of vitamin D. Nevertheless, we feel that advising patients to undertake lifestyle changes may not be sufficient …