Review of gestational diabetes mellitus and vitamin D

Abstract

Most of what we know about the link between vitamin D levels and GDM comes from observational studies with different results. Two well-conducted meta-analyses published recently from this work found evidence of a small link between low 25(OH)D levels and an increased risk of GDM. It is yet uncertain, though, if a vitamin D deficit affects the pathophysiology that leads to the development of GDM. To our knowledge, there hasn't been a published major randomized trial of different vitamin D doses in women at high risk for getting GDM or who already have GDM. RCTs are needed to prove that getting enough vitamin D helps prevent or treat GDM because the only studies done so far are encouraging but not conclusive.7–14% of pregnancies are complicated by gestational diabetes mellitus (GDM). Pregnancy also frequently results in vitamin D insufficiency. However, it is unknown whether vitamin D supplementation can prevent GDM. New research indicates that vitamin D delivery can increase insulin sensitivity and glucose tolerance. Observational studies provide conflicting evidence regarding the association of low serum 25(OH) D) levels with GDM. According to two recent systematic evaluations, vitamin D insufficiency raises the risk of GDM. However, the observational and varied nature of the included studies restricts these reviews. The biggest worry is that we don't know how significant confounding factors like obesity and race/ethnicity might influence the association. Only a few randomized controlled trials have been conducted. Still, they are necessary to determine if extra vitamin D supplements, beyond what is usually found in prenatal vitamins, can help GDM patients with glucose tolerance.