Efficacy of oral vitamin D on glycated haemoglobin (HbA1c) in type 2 diabetics having vitamin D deficiency - A randomized controlled trial.

Objective: To study the efficacy of oral vitamin D in improving glycaemic control of patients with type 2 diabetes by reducing glycated haemoglobin levels.
Methods: This randomised control trial was carried out at Mayo Hospital, Lahore, from February 5 to August 5, 2016, and comprised type 2 diabetes patients aged 40-70 years visiting the outpatient clinics. They were randomly divided into two groups by using the lottery method. Group A received oral vitamin D along with metformin and group B received metformin only. Blood samples of both the groups were tested for glycated haemoglobin at three months to assess the change. SPSS 21 was used for data analysis.
Results: There were 140 patients divided into two groups of 70(50%) each. Mean age in Group A was 54.80±8.55 years and 58.40±7.98 years in Group B. No significant difference was seen in glycated haemoglobin levels at baseline (p>0.05). However, after 3 months post-treatment the levels significantly differed (p<0.05) in favour of Group A.
Conclusions: Vitamin D supplementation had a significant effect in lowering glycated haemoglobin level in patients with type 2 diabetes.