Maternal gestational weight gain and offspring vitamin D level: a multicentre retrospective cohort study

This study examined the association between maternal gestational weight gain (GWG) and offspring vitamin D levels.

In this retrospective cohort study, 0-5-year-old children attending routine health checks at 12 centres across 10 cities in Jiangsu Province (April 2014-March 2015) were enrolled via stratified random cluster sampling. Serum 25(OH)D was measured by ELISA.

Among 1,984 mother-offspring pairs, GWG ≤10 kg was associated with an increased risk of vitamin D deficiency (<50 nmol/L) in the unadjusted model (OR = 1.550, 95% CI: 1.196-2.008), and this association remained significant in Model 1 (OR = 1.820, 95% CI: 1.357-2.441), Model 2 (OR = 1.545, 95% CI: 1.060-2.253), and Model 3 (OR = 1.882, 95% CI: 1.228-2.883). For vitamin D insufficiency (50-<75 nmol/L), GWG >19 kg was associated with an increased risk in the unadjusted model (OR = 1.309, 95% CI: 1.026-1.670) and in Model 1 (OR = 1.312, 95% CI: 1.021-1.685), Model 2 (OR = 1.872, 95% CI: 1.305-2.684), and Model 3 (OR = 1.609, 95% CI: 1.054-2.456). This association was statistically significant in Model 3 but was no longer significant after FDR correction.

To our knowledge, this is the first multicentre study to report an association between GWG ≤10 kg and an increased risk of vitamin D deficiency in offspring, and between GWG >19 kg and an increased risk of vitamin D insufficiency. However, the latter association did not remain significant after FDR correction in sensitivity analyses based on Model 3 and requires confirmation in further studies.