Background: Vitamin D may play a pivotal role in regulating insulin secretion and insulin sensitivity. However, the effect of vitamin D intake, either from the diet or from supplements, on the development of gestational diabetes mellitus (GDM) remains unclear. We prospectively examined the association of prepregnancy habitual intake of vitamin D from diet and supplements with the risk of incident GDM in a well-established cohort.
Methods: The present study was performed on 21 356 singleton pregnancies from 15 225 women in the Nurses' Health Study II cohort. Diet information, including vitamin D intake from food sources and supplements, was assessed in 1991 and every 4 years thereafter by validated food frequency questionnaires. Log-binomial models with generalized estimating equations were used to estimate relative risks (RRs) and 95% confidence intervals (CIs).
Results: During 10 years of follow-up, 865 incident GDM cases were documented. After adjustment for age, parity, race/ethnicity, family history of diabetes, dietary and lifestyle factors, and body mass index, the RRs (95% CIs) of GDM risk associated with supplemental vitamin D intake of 0, 1-399, and ≥400 IU/day were 1.00 (reference), 0.80 (0.67-0.96), and 0.71 (0.56-0.90), respectively (Ptrend = 0.002). Dietary and total vitamin D intakes were also inversely associated with GDM risk, but the associations were not statistically significant.
Conclusions: Prepregnancy supplemental vitamin D intake was significantly and inversely associated with risk of GDM. This study indicates potential benefits of increasing vitamin D intake from supplements in the prevention of GDM in women of reproductive age.
Keywords: diet; gestational diabetes mellitus; nutrition; preconception; vitamin D; 妊娠糖尿病; 孕前; 维生素D; 营养; 饮食.
© 2017 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and John Wiley & Sons Australia, Ltd.