Vitamin D and Calcium Homeostasis for Prevention of Type 2 Diabetes (CaDDM)

The purpose of the randomized trial is to quantify the effect of vitamin D and calcium supplementation on beta-cell function, insulin sensitivity, glucose tolerance and systemic inflammation and other cardiometabolic outcomes in ambulatory adults at high risk for type 2 diabetes.

There is animal and human observational evidence to suggest that vitamin D and calcium are important in modifying t2DM risk but there are critical gaps in our knowledge about the clinical magnitude of the association with t2DM and potential mechanisms in humans. We are conducting a randomized trial to quantify the effect of vitamin D and calcium supplementation on beta-cell function, insulin sensitivity, glucose tolerance and systemic inflammation and other cardiometabolic outcomes in ambulatory adults at high risk for t2DM. We anticipate that the research proposed in this application is significant because it will provide the basis for defining feasible nutritional interventions that promotes prevention of t2DM. Based on the results of the proposed studies and future work in this area, vitamin D and calcium supplementation can assume an important role in the treatment of t2DM and in the prevention of the disease in the 41 million Americans who are at risk of developing t2DM.

Inclusion Criteria: Ethnicity: all ethnic groups Gender: men and women Age Lower age limit: 40 years inclusive Upper age limit: NONE BMI Lower BMI limit: 25 inclusive Upper BMI limit: 40 inclusive Glucose Intolerance / Mild Diabetes defined as Fasting glucose ≥100 mg/dl OR 2-hr glucose after OGTT ≥140 mg/dl OR 5.8 ≤ Hemoglobin A1c ≤ 7 Major Exclusion Criteria: Diabetes requiring pharmacotherapy Smoking Hyperparathyroidism Hypercalcemia (Calcium > 10.5 mg/dl) Kidney stone Pregnancy

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Nunez Lopez YO, Pittas AG, Pratley RE, Seyhan AA. Circulating levels of miR-7, miR-152 and miR-192 respond to vitamin D supplementation in adults with prediabetes and correlate with improvements in glycemic control. J Nutr Biochem. 2017 Nov;49:117-122. doi: 10.1016/j.jnutbio.2017.08.007. Epub 2017 Aug 26.

Alzaman NS, Dawson-Hughes B, Nelson J, D'Alessio D, Pittas AG. Vitamin D status of black and white Americans and changes in vitamin D metabolites after varied doses of vitamin D supplementation. Am J Clin Nutr. 2016 Jul;104(1):205-14. doi: 10.3945/ajcn.115.129478. Epub 2016 May 18.

Mitri J, Dawson-Hughes B, Hu FB, Pittas AG. Effects of vitamin D and calcium supplementation on pancreatic beta cell function, insulin sensitivity, and glycemia in adults at high risk of diabetes: the Calcium and Vitamin D for Diabetes Mellitus (CaDDM) randomized controlled trial. Am J Clin Nutr. 2011 Aug;94(2):486-94. doi: 10.3945/ajcn.111.011684. Epub 2011 Jun 29.