Directly extending our prior work in this area we have designed and are currently conducting a multi-centers (22 U.S. centers), randomized, double-masked, placebo-controlled, parallel-group primary prevention clinical trial to evaluate the safety of vitamin D supplementation and its efficacy on prevention of diabetes in people at high risk for diabetes.
Vitamin D in established type 2 diabetes (DDM2 study)
DDM2 is one-year long randomized, double-masked, placebo-controlled trial to test the effect of vitamin D3 supplementation on insulin secretion and sensitivity in persons with established type 2 diabetes of mild/moderate severity. The study has been completed and is currently in the data analyses phase.
This was an observational study to assess the longitudinal association between vitamin D status – assessed by blood level of 25-hydroxyvitamin D – and risk of developing diabetes among people at high risk for diabetes in the Diabetes Prevention Program (DPP), which is a cohort of people at high risk for diabetes.
This was an observational study to assess the longitudinal association between vitamin D status and risk of developing diabetes within the Nurses Health Study (NHS), which an ongoing large observational cohort in women.
Calcium and Vitamin D for Diabetes Mellitus (CaDDM) study
The CaDDM study was a randomized controlled clinical trial that examined the effects of 4 months of vitamin D and/or calcium supplementation on disposition index in adults at risk for type 2 diabetes or with early diabetes (not on medications).
Using data from a completed trial, this was a post-hoc analysis to test the hypothesis that vitamin D and calcium supplementation improve fasting blood glucose and insulin resistance in nondiabetic adults aged 65 years or older.
The study systematically reviewed and synthesized evidence from trials that compared vitamin D3 supplementation with placebo or a non-vitamin D supplement in adults with normal glucose tolerance, prediabetes, or type 2 diabetes.