The Effect of Vitamin D Supplementation on Improving Glycaemic Control in Diabetic Vitamin D-Deficient Pregnant Women: A Single-Blinded Randomized Control Trial

Gestational diabetes mellitus is one of the most common conditions complicating pregnancy. Vitamin D deficiency is closely associated with gestational diabetes mellitus.

To study the effect of vitamin D supplementation on diabetic pregnant women with vitamin D deficiency.

This randomized controlled study was conducted with 100 diabetic pregnant women. They were randomized into group A and group B. Group A were screened for vitamin D deficiency once diagnosed with GDM of which 40 were found to be deficient and allotted to group D (n = 40) and were supplemented with 60,000 units of vitamin D3 per month. Group B were given routine antenatal care and were screened for vitamin D deficiency when they were admitted for delivery, and 39 of them were found to have vitamin D deficiency and were studied as control group C (n = 39). Ten women in both the groups had normal levels of vitamin D, and one of them was excluded from the study as she had molar pregnancy. The vitamin D supplemented group D and the control group C were matched for age and parity at the baseline.

There was a significant increase in the mean insulin and metformin requirements in both the supplemented and control groups. Vitamin D supplementation did not improve the glycaemic control in diabetic pregnant women.

Vitamin D supplementation did not decrease insulin resistance or improve the glycaemic control in diabetic pregnant women with vitamin D deficiency.