Vitamin D3 supplementation improves insulin sensitivity in subjects with impaired fasting glucose

Vitamin D3 supplementation improves insulin sensitivity in subjects with impaired fasting glucose

Shaban Nazariana, John V. St. Petera, b, d, Raymond C. Bostonc, Sidney A. Jonesd and Cary N. Mariasha, Corresponding Author Contact Information, E-mail The Corresponding Author

a Division of Endocrinology and Diabetes, University of Minnesota, Minneapolis, Minn

b College of Pharmacy, University of Pennsylvania, Philadelphia, Pa

c Department of Biostatistics and Epidemiology, University of Pennsylvania, Philadelphia, Pa

d Hennepin County Medical Center, Minneapolis, Minn
Received 2 March 2011;
revised 18 April 2011;
accepted 13 May 2011.
Available online 7 June 2011.

Vitamin D has in vitro and in vivo effects on β cells and insulin sensitivity. Vitamin D deficiency (VDD) has been associated with the onset and progression of type 2 diabetes mellitus (DM-2). However, studies involving supplementation of vitamin D in subjects with previously established diabetes have demonstrated inconsistent effects on insulin sensitivity. The aim of this open-label study was to assess the effects of high-dose vitamin D3 supplementation on insulin sensitivity in subjects with VDD and impaired fasting glucose. We studied 8 subjects with VDD and prediabetes with the modified, frequently sampled intravenous glucose tolerance (mFSIGT) test before and after vitamin D supplementation. Vitamin D3 was administered as 10,000 IU daily for 4 weeks. The mFSIGT was analyzed with MinMod Millennium (purchased from Dr. Richard Bergman, Keck School of Medicine of USC, Los Angeles, Calif) to obtain estimates of acute insulin response to glucose (AIRg), insulin sensitivity (SI), and disposition index (DI). We found that AIRg decreased (P = 0.011) and SI increased (P = 0.012) after a intervention with vitamin D. If these findings are repeated in a randomized, double-blind study, the results indicate that orally administered high-dose vitamin D3 supplementation improves insulin sensitivity in subjects with impaired fasting glucose and suggests that high-dose vitamin D3 supplementation might provide an inexpensive public health measure in preventing, or at least delaying, the progression from impaired fasting glucose to diabetes.

Abbreviations: AIRg, acute insulin response to glucose; BMI, body mass index; DI, disposition index; GCRC, General Clinical Research Center; mFSIGT, modified frequently sampled intravenous glucose tolerance test; SI, insulin sensitivity; VDD, vitamin D deficiency; vitamin D, cholecalciferol
Article Outline

Subjects and Methods
Study participants
Study design

Methods
Intervention
Outcomes measures
Statistics

Results

Discussion

Acknowledgements

References

We will need to see a randomized, double-blind study but this is perfectly inline with what John Cannell says about over weight people, they need much more D3 to get positive effects.