The pathogenesis of congenital diaphragmatic hernia (CDH) is largely unknown; however, vitamin A seems to play a role in diaphragmatic development. Previous case–control studies reported that maternal dietary vitamin A intake was inversely associated with the risk of CDH. To our knowledge, however, there is no prospective evidence regarding this association. Our aim was to examine whether maternal intake of vitamin A was associated with CDH occurrence. Baseline data, from the Japan nationwide birth cohort study (2011–2014) of 89 658 mothers (mean age at delivery = 31·2 years) who delivered singleton live births, were analysed. We assessed dietary habits using an FFQ focused on the first trimester and estimated the daily intake of total vitamin A (retinol activity equivalents), retinol, provitamin A carotenoids and vegetables. The occurrence of CDH was ascertained from medical records. A total of forty cases of CDH were documented. The adjusted OR of CDH occurrence for the high total vitamin A intake category (median = 468 μg/d) was 0·6 (95 % CI 0·3, 1·2) with reference to the low intake category (230 μg/d). When we restricted to mothers with a prepregnancy BMI of 18·5–24·9 kg/m2, vitamin A intake was inversely associated with the risk of their children being born with CDH (OR 0·5, 95 % CI 0·2, 1·0). Even given the limited number of cases in the study, our findings provide additional evidence to link vitamin A with CDH.

Xanthophylls, such as lutein and zeaxanthin, have received increasing interest in recent years because of positive correlations between their consumption and the prevention of eye diseases. Numerous human intervention studies have been conducted with lutein to estimate the bioavailability from different formulations. The present study was designed to obtain basic data on the absorbance efficiency of the monohydroxylated counterparts of lutein and zeaxanthin: α- and β-cryptoxanthin. A corn-oil-based diet comprising ß-cryptoxanthin from papaya purée and α-cryptoxanthin from green carrot leaves was fed to five female Wistar rats for 8 consecutive days at a rate of 17·3 nmol/d and 9·2 nmol/d, respectively. The identity of the xanthophylls in the supplement was ascertained by LC-(APCI)MS analyses, and xanthophylls present in liver and plasma samples were determined by HPLC/diode array detector (DAD). The β-cryptoxanthin concentrations of rat livers in the treatment group were statistically distinguishable (P < 0·01) from those present in the livers of the control group that were fed a basic diet. α-Cryptoxanthin, the second xanthophyll present in the supplement, was not found in rat livers in the treatment group. Plasma samples were free of xanthophylls. This is the first report proving that β-cryptoxanthin has a higher absorption efficiency than α-cryptoxanthin in rats, at least from a minimally processed oil-based xanthophyll supplement.