Effect Of Vitamin D Supplement 0n The Islet-β Cell Function And Glucolipid Metabolism In Prediabetes:A Randomized Controlled Trial

Objective:Type 2 diabetes mellitus（T2DM）and vitamin D deficiency is now growing thr-eating the people’s health.There are some epidemiological studies have shown that the vitamin D in our body plays an important role in isletβcell function,insulin resis-tance and the progressing of type 2 diabetes.But now about vitamin D supplement tr-eatment has potential effects on the glucose homeostasis is still exists certain controversial.Methods:This is a 10-months randomized,placebo-controlled trial.From October 2015 to December 2015,We enrolled 140 IGT（impaired glucose tolerance）or/and IFG（im-paired fasting glucose）patients who come from the inpatient or outpatient of endocrine department of the affiliated hospital of Taishan medical college.The patients were rando-mly divided into treatment group and control group.Treatment group was orally given vitamin D₃ drops 800IU by one time per day and control group was orally given the same appearance of placebo capsuleby one time perday.At baseline and after inte-rvention for5,12 months,the body mass index（BMI）,systolic blood pressure（SBP）,diastolic blood pressure（DBP）,fasting plasma glucose（FPG）,2 hour postload plasma glucose（2hPPG）,glycosylated hemoglobin（HbA1c）,triglycerides（TG）,total cholesterol（T C）,High density lipoprotein cholesterol（HDL-C）,Low density lipoprotein cholesterol（LDL-C）,fasting insulin（FINS）,homeostasis model assessment insulin resistan ce（HOMA-IR）and isletβcell function index（HOMA-β）,serum 25（OH）D,serum calcium.Results:At baseline,no differences between the two groups were observed in all indicators（P>0.05）.The serum 25（OH）D of The experimental group and control group in baseline are both below normal level（30ng/ml）,They all belong to vitamin D deficiency,averages are 24.81ng/ml（control group）and 24.58ng/ml（experimental group）.The serum 25（OH）D of experimental group have a significant rise in the twentieth week,up to 28.85ng/ml,and compared with the control group,we could find that there were significantly statistical differences（P<0.001）between the two groups.At the same time,no differences between the two groups were observed in other indicators（P>0.05）.Until the end of the experiment,The serum 25（OH）D of the experimental group has attained to 31.65ng/ml,and 93%of the participants had achieved a status of serum vitamin D adequate（>30ng/ml）.and the treatment group was lower in 2hPPG（9.03mmol/L vs 9.65mmol/L）level than control group（P<0.05）,no differences between the two groups were observed in other indicators（P>0.05）.Conclusion:Serum 25（OH）D is thought to play an important role in the glucose metabolism of people with prediabetes.A certain dose of vitamin D supplements can signifcantly impove th glucose metabolism of people with prediabetes.