The Effect of Vitamin D3 Intervention on the Association Among Vitamin D3, Adiponectin, and Body Mass Index in Pregnant Women With Gestational Diabetes.

INTRODUCTION: Vitamin D3 (VD3) deficiency is a strong predictor of gestational diabetes. Therefore, VD3 supplementation during the antenatal period could prevent the development of gestational diabetes via its effects on insulin secretion, insulin sensitivity, body mass index (BMI), and adiponectin production.

OBJECTIVES: To observe the effect of VD3 supplementation on adiponectin and BMI and to explore the effect of VD3 supplementation on the association among VD3, adiponectin, and BMI in pregnant women with gestational diabetes.

METHODS: A randomized control trial was performed after receiving consent at Postgraduate Medical Institute, Lahore. Subjects at 20-26 weeks of gestation with gestational diabetes and with a deficiency/insufficiency of VD3 were included. The study excluded those who were smokers, had multiple pregnancies, or had other gestational complications. Subjects were categorized into interventional (VD3 supplementation) and control groups. The institutional ethical committee approved the study. Serum samples were used for enzyme-linked immunosorbent assay estimation of VD3 and adiponectin levels. Statistical Product and Service Solutions (SPSS) (IBM SPSS Statistics for Windows, Version 21.0, Armonk, NY) software was used to analyze data. Student t-tests were applied to compare quantitative variables, and Chi-square tests were utilized to compare qualitative variables. Pearson's correlation and linear regressions were performed to explore the association. At a 95% confidence interval, a p-value of ≤0.05 was taken as significant.

RESULTS: With an increase in serum VD3 levels, a decrease in serum adiponectin level was observed in pregnant women with gestational diabetes (interventional group: r = -0.088, p = 0.74); however, after the intervention of VD3 supplementation in the same subjects, an increase in serum adiponectin level was noted with an increase in VD3 (interventional group: r = 0.273, p = 0.28). A significant direct relationship was found between BMI and adiponectin in the same study population (interventional group: r = 0.7, p = 0.001). Interestingly, after the intervention, BMI tends to be less likely to increase adiponectin levels (interventional group: r = 0.09, p = 0.73). Moreover, an inverse association was exhibited between BMI and VD3 levels in all the study groups before intervention (control group: r = -0.07, p = 0.78; interventional group: r = -0.035, p = 0.89) and after intervention (interventional group: r = -0.12, p = 0.65), except in the control group after the intervention span, where BMI mildly raises the VD3 levels (r = -0.12, p = 0.65).

CONCLUSION: BMI increases with an increase in serum adiponectin levels in gestational diabetic women, but after VD3 supplementation, BMI was less likely to influence adiponectin. Also, with an increase in BMI, a decrease in the VD3 in all study groups was observed except in the control group after VD3 supplementation.