Higher vitamin D intake during pregnancy may protect children from being overweight: BMJ

Worldwide, the prevalence of vitamin D insufficiency is high among pregnant women. Vitamin D contributes to the embryo implantation and is also important for placental function.

A new study by Anna Amberntsson and team reported that maternal vitamin D intake and child growth and risk of overweight varied by pre-pregnancy Body Mass Index (BMI). Vitamin D intake during pregnancy affects offspring postnatal growth, and that a higher vitamin D intake during the pregnancy has a protective effect against the risk of childhood overweight but only in children of mothers with normal prepregnancy weight.

This study is published in BMJ Open journal.

The objective of the study was to examine the associations between maternal vitamin D intake and childhood growth and risk of overweight up to 8 years. They further examined the effect modification by maternal pre-pregnancy body mass index (BMI).

The study was a prospective population-based pregnancy cohort study. A total of 58,724 mothers and 66,840 singleton children, with information on maternal vitamin D intake during the pregnancy and minimum one postnatal anthropometric measurement. Predicted weight and height growth trajectories and velocities from 1month to 8 years, rapid growth during infancy and toddlerhood, and risk of overweight in preschool and school age.

The results of the study were found to be

• Maternal vitamin D intake was associated with lower weight trajectory, lower odds of rapid weight growth and higher odds of childhood overweight.

• In children of mothers with pre-pregnancy normal weight, maternal vitamin D intake was negatively associated with weight trajectory (15 µg/day, also had 0.86 (95% CI 0.77 to 0.97) and 0.88 (95% CI 0.79 to 0.99) lower odds for overweight at 3 years, compared with reference.

• In contrast, in children of mothers with prep-regnancy overweight (BMI ≥25 kg/ m2 ), Vitamin D intake was positively associated with weight trajectory.

• Children of mothers with overweight, with maternal vitamin D intake of 5–9.9 µg/day, also had (1.09 (95% CI 1.01 to 1.18) and 1.12 (95% CI 1.02 to 1.23)) higher odds for overweight at 5 years and 8 years, compared with reference.

Amberntsson and team concluded that "Maternal vitamin D intake affects postnatal growth and is inversely associated with childhood overweight in children of mothers with normal weight. Associations between maternal vitamin D intake and child growth and risk of overweight varied by pre-pregnancy BMI."

For further information: http://dx.doi.org/10.1136/ bmjopen-2021-048980.