Vitamin D Status among Egyptian Pregnant Women with Gestational Diabetes Mellitus

Abstract

itamin D, a secosteroid that is synthesized in skin and sequentially metabolized in liver and kidneys in humans, it has been well-known for its function in maintaining calcium and phosphorus homeostasis and promoting bone mineralization. However, the ubiquitous distribution of intracellular vitamin D receptor across diverse tissues (Holick et al., 2007) and the emerging epidemiological evidence documenting increased risks of hypertension , cardiovascular disease, and selected cancers (Giovannucci et al., 2008). Evidence is also accumulating for a role of vitamin D in maintaining normal glucose homeostasis. For instance, in both animal and human studies, vitamin D depletion was significantly related to insulin resistance and impaired insulin secretion. Notably, this condition is reversible upon repletion of vitamin D. Moreover, a significant and strong association between vitamin D deficiency and ß-cell dysfunction has been reported in healthy, non-diabetic, or diabetic populations (Chiuk et al., 2004). Furthermore, circulating concentrations of 25-hydroxyvitamin D (25-[OH] D), the primary circulating form of vitamin D, were significantly and inversely related to the risk for type 2 diabeteand related phenotypes in epidemiological studies(Forouhi et al., 2008). It has long been known that vitamin D deficiency is prevalent among pregnant women (Bodnar et al., 2007). For instance, recent data among pregnant women in northern United States indicated that vitamin D deficiency occurred in 29.2% of black women and 5% of white women (Bodnar et al., 2007). Data on the role of vitamin D in glucose homeostasis during pregnancy and the development of gestational diabetes mellitus (GDM) are scanty and findings are inconsistent. In a cross-sectional study (Maghboolizet al., 2008), serum concentrations of 25-[OH] D measured at the time of GDM screening test (24–28 weeks of gestation) were significantly lower in GDM women than in normal glucose tolerance pregnant women. However, In an Indian population, no significant association between 25-[OH] D concentrations and GDM risk was observed (Farrant et al., 2008). The aim of our study is to assess the relationship between vitamin D status and gestational diabetes mellitus in Egyptian women. The study was conducted on 90 pregnant womens ag