Effective vitamin d supplementation among women with gestational diabetes and perinatal outcomes: results of a clinical trial

Background Gestational diabetes mellitus (GDM) is a common clinical condition worldwide that affects the health of women and their offspring. Theaim was to assess whether a protocol of vitamin D supplementation among women with GDM was efficient in increasing vitamin D levels at the end of pregnancy, and to explore whether the supplementation reduced the occurrence of adverse neonatal outcomes among those women. Methods A controlled clinical trial.Vitamin D was assessed at baseline (< 28 gestational weeks) and after 8 weeks of intervention and categorized as adequate (> 30ng/mL), insufficient (20–29.9ng/mL), or deficient (< 20ng/mL). Women with insufficiency received 2000 UI daily of vitamin D supplementation and those with deficiency received 7000 UI daily for 8 weeks. The outcomes 25-hydroxyvitamin D [25(OH)D] concentration at 28 weeks, glycemic control, total gestational weight gain, birth weight, and gestational age at birth. Statistical analyses included Chi-squared or Fisher’s exact tests for categorical variables and Kruskall–Wallis test for continuous variables to compare the groups. Results At baseline, 59 pregnant women with GDM allocated to the study group were evaluated at baseline.Vitamin D status changed between the first and second examinations in 70% of the women investigated. The insufficient and deficient groups showed a tendency towards improvement in glycemic control (p = 0.096). No differences were identified between the groups in terms of the neonatal variables. Conclusion Supplementation was effective in adjusting serum vitamin D levels, and its effect on glycemic control appeared promising in this preliminary investigation.