A Preliminary Study Investigating The Effects Of Vitamin D Phototherapy On Blood Glucose Levels In A Sample Of Pre-Diabetics

Abstract

Improved insulin sensitivity and glucose tolerance may be attributable to vitamin D sufficiency. An experimental design was created to investigate the use of phototherapy to increase serum vitamin D levels and improve circulating blood glucose levels in pre-diabetics. Seven participants with a pre-diabetic condition were randomly allocated to either 3 months of phototherapy or no therapy. OGTT, HbA1c, and serum vitamin D levels were assessed before and after treatment. In 2 treatment participants, pre-diabetes status was reduced from combined IFG/IGT to iIFG in one and iIGT in the second, while 1 control participant developed combined IFG/IGT and another, type 2 diabetes. HbA1c values improved in the phototherapy group but not in the controls. Phototherapy also increased serum vitamin D levels in the treatment group but not in the controls. This pilot study suggests that the experimental protocol was effective and it should be implemented in a larger sample size to confirm those trends.