Routine use of vitamin D supplements has increased substantially in the United States. However, the safety and tolerability of long-term use of high-dose vitamin D are not known.  This pre-specified analysis in D2d assessed the safety and tolerability of...

This secondary analysis concluded that supplementation with vitamin D3 for 24 months did not improve an OGTT derived index of β-cell function in people with prediabetes not selected based on baseline vitamin D status; however, there was benefit among...

Despite evidence for associations between low circulating 25(OH)D concentration and kidney disease, few clinical trials have evaluated the effect of vitamin D supplementation on kidney outcomes. The Vitamin D and Type 2 Diabetes (D2d) study was a randomized clinical...

Observational studies suggest that low vitamin D status may be a risk factor for cancer. In a population with prediabetes and overweight/obesity that is at higher risk of cancer than the general population, we sought to determine if vitamin...

The manuscript explains that results from recent trials are congruent with a large body of evidence from observational studies indicating that vitamin D has a role in modulating diabetes risk. Participant-level meta-analysis of the 3 largest trials should provide a...

The manuscript explains how postrandomization biases may influence the estimate of efficacy of supplemental vitamin D in diabetes prevention trials. In the Vitamin D and Type 2 Diabetes (D2d) study, repeated measures of serum 25-hydroxyvitamin D level provided...

In the commentary Dr. Pittas and Dr. Balk explain that although meta-analyses increase statistical power, allowing more precise effect estimates, for them to be credible certain methodological criteria must be met. Even if the methodology is sound, the strength...

This analysis used D2d data (individuals with complete screening and baseline visit data) to calculate HGI, identify demographic and clinical variables associated with HGI, and determine how HGI is associated with prediabetes and diabetes diagnosis. These analyses will lay...

A presentation of the results took place at the annual American Diabetes Association meeting in San Francisco on Friday, June 7th. Results were published in the New England Journal of Medicine.