The global burden of vitamin D deficiency or insufficiency is of great concern for public health. According to recent studies, vitamin D deficiency is an important etiological factor in the pathogenesis of many chronic diseases. Whether or not there is a connection between 25-hydoxyvitamin D (25(OH)D) status and overall mortality is a matter of considerable debate. A new meta-analysis confirmed that low 25(OH)D levels were associated with a significant increased risk for all-cause mortality. Individuals with severe vitamin D deficiency have almost twice the mortality rate as those with 25(OH)D level ≥ 30 ng/mL, (≥75 nmol/L). Unlike previous meta-analyses which suggested that serum 25(OH)D > 50 ng/mL was associated with increased mortality, this new analysis found that there was no increased risk even when 25(OH)D levels were ≥70 ng/mL. In general, closer attention should be paid to vitamin D deficiency in medical and pharmaceutical practice than has been the case hitherto. The results of these studies are consistent with the recommendation to improve the general vitamin D status in children and adults by means of a healthy approach to sunlight exposure, consumption of foods containing vitamin D and supplementation with vitamin D preparations.