title: Effect of 1, 25(OH)₂ vitamin D₃ on glucose homeostasis and DNA damage in type 2 diabetic mice.
abstract: OBJECTIVE
  The purpose of the study was to examine the effect of 1, 25(OH)₂ Vitamin D₃ supplementation on type 2 diabetic (T2DM) mice.
  
  
  METHODS
  A total of 24 mice were taken and divided into three groups of control; diabetic and diabetic + vitamin D supplemented ones. Serum calcium level, fasting blood glucose level (FBG), hexokinase activity, glucose-6-phosphatse and fructose 1,6 bisphosphatase activity were measured to establish a relevant correlation between vitamin D supplementation and hyperglycemia in T2DM.
  
  
  RESULTS
  There occurred an increase in FBG levels (250 ± 0.41 mg/dl) and a significant decrease in serum calcium levels in the diabetic group (8.63 ± 0.40 mg/ml) both of which reached near control levels on vitamin D₃ supplementation. The activity of the glucose metabolic enzymes was also assayed in diabetic group and was found to be deviated from control group; hexokinase (0.0241 ± 0.014 μg/mg/ml) FBPase (0.433 ± 0.002 μg/mg/ml) and G6Pase (0.918 ± 0.02 μg/mg/ml). However, the activity of these enzymes returned to near control values with hexokinase activity reaching 0.717 ± 0.003 μg/mg/ml on vitamin D₃ supplementation. The FBPase and G6Pase activities were decreased to 0.2733 ± 0.008 μg/mg/ml and G6Pase 0.71 ± 0.01 μg/mg/ml respectively. In addition to enzymatic analysis, the organs of all three groups of mice were subjected to comet assay. The diabetic group receiving vitamin D supplementation showed a marked recovery exhibiting shorter tail length both in liver (21.80 ± 2.40 μm) and pancreatic cells (19.25 ± 1.90 μm) as compared to the diabetic group exhibiting a tail length of 30.41 ± 2.50 μm and 32.45 ± 2.87 μm in liver and pancreatic cells respectively.
  
  
  CONCLUSIONS
  The present study shows that vitamin D₃ supplementation is positively correlated with decrease in blood glucose level and serum calcium level in fasting condition. This suggests a positive influence of vitamin D on glucose homeostasis. Besides, the activity of various glucose metabolic enzymes (hexokinase, FBPase and G6Pase) as shown by our results and the remarkable shortening of DNA tail length in vitamin D supplemented diabetic group as compared to diabetic group without supplementation further support the idea that vitamin D supplementation might be an add-on therapy for patients with T2DM.
authors: Department of Biochemistry, Faculty of Life Sciences, Aligarh Muslim University, Aligarh, U.P., India-202002.
authors: Dilnasheen
authors: D
authors: Meerza
authors: Imrana
authors: I
authors: Naseem
authors: Jamal
authors: J
authors: Ahmed
mesh_terms: D000496:Alloxan; D000818:Animals; D002117:Calcitriol / Q000008:administration & dosage; D002118:Calcium / Q000097:blood; D020552:Comet Assay; D004249:DNA Damage; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000178:diet therapy* / Q000378:metabolism / Q000473:pathology; D019587:Dietary Supplements; D005260:Female; D006597:Fructose-Bisphosphatase / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D005952:Glucose-6-Phosphatase / Q000378:metabolism; D006593:Hexokinase / Q000378:metabolism; D006706:Homeostasis; D006943:Hyperglycemia / Q000517:prevention & control*; D006996:Hypocalcemia / Q000150:complications / Q000517:prevention & control*; D007003:Hypoglycemia / Q000517:prevention & control; D007274:Injections, Intraperitoneal; D008099:Liver / Q000201:enzymology / Q000473:pathology; D051379:Mice; D010179:Pancreas / Q000473:pathology; D014807:Vitamin D / Q000627:therapeutic use*
chemical_list: D014807:Vitamin D; D000496:Alloxan; C515658:HK1 protein, mouse; D006593:Hexokinase; D006597:Fructose-Bisphosphatase; D005952:Glucose-6-Phosphatase; D002117:Calcitriol; D005947:Glucose; D002118:Calcium