Impact of new vitamin D data on future studies and treatment

Abstract

This review evaluates recently published data on clinical effects of vitamin D supplementation, focusing on randomized, placebo-controlled trials and nontraditional actions on the cardiovascular and immune systems. Several randomized trials evaluating vitamin D therapy have recently emerged, in both the general population and in individuals with chronic kidney disease (CKD). In the former, measurable effects on cardiovascular risk factors have not been detected, with the possible exception of a modest reduction in blood pressure. Studies aimed at boosting immunity have demonstrated efficacy only in specific, high-risk populations. In CKD, the benefits of nutritional vitamin D appear largely limited to earlier stages of disease. Benefits of active vitamin D agents, outside of their known effects on mineral metabolism, have also thus far eluded detection. One possible exception that has accumulated supportive evidence is the link between active vitamin D analogs and decreased proteinuria. Large-scale clinical trials, now underway, will be critical to understanding of the potential benefits and hazards of vitamin D treatment. New trials evaluating the effects of vitamin D supplementation have failed to reveal any robust clinical benefits beyond its known actions on mineral and bone disease.