Cohort characteristics
Mother and infant characteristics of the 704 offspring (352 intervention group and 352 placebo) with data on atopic eczema at any of ages 12 (n=636), 24 (n=611) or 48 (n=450) months were similar in the intervention and placebo groups with the exception of longer breastfeeding duration in the intervention group (Table 1). Mother and infant characteristics apart from breastfeeding duration were also similar for the subgroups followed up at each of the three postnatal ages (Supplementary Table 1), and the 704 mothers and offspring included had characteristics similar to those of the overall group recruited to MAVIDOS (Supplementary Table 2). Baseline maternal serum 25(OH)D levels at recruitment in early pregnancy were similar in the intervention and placebo groups. In late pregnancy, maternal serum 25(OH)D levels were higher in the intervention group compared with the placebo group (Table 1).