Correlation between low serum vitamin D levels and Gestational Diabetes Mellitus among pregnant women in the rural area attending tertiary care center

Correlation between low serum vitamin D levels and Gestational Diabetes Mellitus among pregnant women in the rural area attending tertiary care center Kiranmai G.1, Indira B.2* DOI: https://doi.org/10.17511/joog.2020.i05.01 1 Kiranmai G., Associate Professor, Maharajahs Institute of Medical Sciences, Vizianagaram, Andhra Pradesh, India. 2* Bommi Indira, Assistant Professor, Maharajahs Institute of Medical Sciences, Vizianagaram, Andhra Pradesh, India.


Introduction
Gestational diabetes mellitus (GDM) is defined as carbohydrate intolerance of variable severity with onset or first recognition during pregnancy [1].
Gestational diabetes mellitus (GDM) is one of the most common medical complications of pregnancy.
The disease has important health implications for mother and child.
Early diagnosis and treatment of GDM can reduce adverse pregnancy outcomes, including stillbirth, neonatal macrosomia, neonatal hypoglycemia, birth trauma, and neonatal respiratory distress syndrome as well as decrease the risk of preeclampsia in the The coexistence of insulin resistance and vitamin D deficiency has generated several hypotheses as worsening insulin resistance [12]. Immense interest persists in vitamin D and its potential effects on several pregnancy outcomes including fetal growth, hypertensive disorders, and gestational diabetes mellitus (GDM) [13].
Two factors make vitamin D intriguing to perinatal investigators studying GDM. First, vitamin D has been shown to improve pancreatic exocrine function and insulin sensitivity in animal models. Second, vitamin D status, like most micronutrients, is easily modified by dietary supplementation [13].
The major source of vitamin D is skin after sunlight exposure.
Cutaneous vitamin D synthesis is modulated by several factors including skin pigmentation, clothing, melanin concentration, latitude, climate type, and season [14]. Vitamin D, either produced in the skin de Novo from cholesterol (cholecalciferol) or  [15,16]. The active form 1,25(OH)2D is also produced by the placenta during pregnancy [17] with possible autocrine or paracrine function [18].
Aim of the study § To determine the relationship between low maternal serum vitamin D levels and gestational diabetes mellitus (GDM).

Kiranmai G. et al: Correlation between low serum vitamin D levels
Obs Gyne Review -Journal of Obstetric and Gynecology 2020;6(5) The study was conducted after the Institutional Ethics Committee approval. inverse association was also found with the fasting blood sugar levels which were statistically significant.  Vitamin D could also enhance insulin sensitivity by stimulating insulin receptor gene expression thereby enhancing insulin-mediated glucose transport [19].
Also, vitamin D may be needed to ensure a normal rate of calcium flux across cell membranes and maintenance of an adequate cytosolic calcium pool, which is important for insulin-mediated intracellular signaling in insulin-responsive tissues [20].
Finally, several studies suggest that vitamin D could play a role in the pathogenesis of diabetes mellitus type 2 by affecting insulin sensitivity of β cell function [21,22]. Vitamin D is also essential for proper fetal programming and its deficiency during pregnancy may lead to low birth weight and increased susceptibility to chronic disease later in life [23]. In group A,8% had a history of GDM.
Calcium and periconceptional multivitamin intake in both groups did not show statistical significance.
Jain Madhu et al [24] also had a similar finding in their study.
In However, he found a negative correlation between 25(OH) D and 30 minutes of the blood sugar level, after adjustment of age and BMI [31].
There is a negative correlation between the Vitamin D levels and fasting blood sugar, higher levels of fasting blood sugar were found in women with lower Vitamin D levels. A negative correlation was also seen between the Vitamin D levels and HbA1c, thus indicating poor glycemic control, this inverse relation was found to be statistically significant.
Similar observations were made by El Lithy et al.
Thus, low serum Vitamin D levels were associated with Gestational diabetes mellitus (GDM). So finally, it was concluded that the maternal serum Vitamin D level could be done as a routine investigation in pregnancy and Vitamin D deficiency should be treated to avoid the risk of GDM.

Limitations
India is a country with a high predisposition for insulin resistance leading to Vitamin D deficiency.
Genetic factors in Asian women adds to it. Therefore large-randomized trials are needed to confirm our results and to find if Vitamin D supplementation could improve glycemic control in women with GDM and reduce the adverse outcome in mother and fetus.

Conclusion
The present study concludes that there is a high