title: Effect of Vitamin D supplementation on glycemic control in Type 2 diabetes subjects in Lagos, Nigeria.
abstract: BACKGROUND
  Improvement of glycemic control reduces the risk of diabetic complications. Reports suggest that Vitamin D supplementation improves glycemia. However, there are no data on the influence of Vitamin D on diabetes mellitus (DM) in Nigeria.
  
  
  OBJECTIVE
  To determine the effect of Vitamin D supplementation on glycemic control in Type 2 DM (T2DM) participants with Vitamin D deficiency.
  
  
  METHODS
  This was a single-blind, prospective randomized placebo-controlled trial, involving T2DM participants attending the Diabetes Clinic of the Lagos University Teaching Hospital. Forty-two T2DM participants with poor glycemic control and Vitamin D deficiency were selected following a prior cross-sectional study on 114 T2DM participants for the determination of Vitamin D status and glycemia. These participants were randomized into two equal groups of treatment and placebo arms.
  
  
  METHODS
  Three thousand IU of Vitamin D3 were given to the participants in the treatment arm. Glycemic status was determined at baseline and after 12 weeks. Statistical analysis was performed using Statistical Package for Social Sciences version 20. P < 0.05 was considered statistically significant.
  
  
  RESULTS
  Vitamin D3 supplementation resulted in a significant improvement in serum Vitamin D level and fasting plasma glucose in the treatment arm compared to placebo. There was a nonsignificant reduction in the mean HbA1c level in the treatment group after 12 weeks of Vitamin D3 supplementation (Z = -1.139; P = 0.127) compared to the placebo group, which had a further increase in the mean HbA1c level (Z = -1.424; P = 0.08). The proportion of participants with poor glycemic control (HbA1c > 6.5%) who converted to good control after Vitamin D supplementation was significantly higher in the treatment arm compared to placebo (P < 0.05).
  
  
  CONCLUSIONS
  Vitamin D3 supplementation in persons with T2DM and Vitamin D deficiency results in a significant improvement in glycemic control.
authors.affiliation: Department of Medicine, College of Medicine, University of Lagos, Lagos University Teaching Hospital, Lagos, Nigeria.
authors.forename: Anthony Chinedu
authors.initials: AC
authors.lastname: Anyanwu
authors.affiliation: Department of Medicine, College of Medicine, University of Lagos, Lagos University Teaching Hospital, Lagos, Nigeria.
authors.forename: Olufemi Adetola
authors.initials: OA
authors.lastname: Fasanmade
authors.affiliation: Department of Medicine, College of Medicine, University of Lagos, Lagos University Teaching Hospital, Lagos, Nigeria.
authors.forename: Ifedayo Adetola
authors.initials: IA
authors.lastname: Odeniyi
authors.affiliation: Department of Medicine, College of Medicine, University of Lagos, Lagos University Teaching Hospital, Lagos, Nigeria.
authors.forename: Sandra
authors.initials: S
authors.lastname: Iwuala
authors.affiliation: Department of Pharmacy, Faculty of Pharmaceutical Sciences, College of Medicine, University of Lagos, Lagos, Nigeria.
authors.forename: Herbert Babatunde
authors.initials: HB
authors.lastname: Coker
authors.affiliation: Department of Medicine, College of Medicine, University of Lagos, Lagos University Teaching Hospital, Lagos, Nigeria.
authors.forename: Augustine Efedaye
authors.initials: AE
authors.lastname: Ohwovoriole
keywords: Glycemic control; Type 2 diabetes mellitus; Vitamin D supplementation