Vitamin A consumption in pregnancy and risk of offspring type 1 diabetes

Abstract

Background and aim: Vitamin A have been shown to influence immunity, and animal studies have shown that maternal vitamin A intake could have immunomodulatory effects that may influence offspring type 1 diabetes (T1D) development. There are few human studies that have investigated the association between vitamin A consumption and T1D. This study aimed to examine the association between maternal vitamin A intake during pregnancy and the risk of childhood T1D in the Norwegian, Mother, Father and Child Cohort study (MoBa).

Methods: This study includes 82,605 children born between 2000 and 2009. Children were followed to April 15, 2018. T1D diagnosis was obtained from the Norwegian Childhood Diabetes Registry (NCDR). Maternal vitamin A intake was estimated through a semi-quantitative food frequency questionnaire (FFQ) and divided into quintiles and as well as modeled as a continuous exposure measure (per 100 retinol equivalents, RE/day). Hazard ratios (HR) were estimated using Cox proportional hazard regression, with adjustment for the maternal factors: T1D, pre-pregnant body mass index, smoking, vitamin D intake, education level, and age at delivery. Further analysis was performed to examine if vitamin A from supplements and food sources separately, as well as vitamin A intake below or above the Nordic Nutrition Recommendations (NNRs), was associated with risk of offspring T1D.

Results: During a mean follow-up time of 12.2 years, 345 children developed T1D. The mean intake was 1,665 RE/day. Compared to the mid-quantile, the lowest fifth of total vitamin A intake (HR=1.17, 95% Cl: 0.83, 1.67) and highest fifth (HR=1.11, 95% Cl: 0.78, 1.59) was not statistically significant associated with the risk of offspring T1D. Total vitamin A was not log-linearly associated with T1D (HR per 100 RE/day: 1.00, 95% Cl: 0.99, 1.01). Intake below (HR=1.17, 95% Cl: 0.84, 1.62) or above (HR=1.11, 95% Cl: 0.73, 1.68) the NNRs daily recommended intake (DRI) was not associated with offspring T1D.

Conclusion: Results in this large prospective cohort suggests no overall association between vitamin A consumption in pregnancy and the risk of offspring T1D.