Calcium plus vitamin D supplementation during pregnancy reduces postpartum fat mass in adolescents: A randomized...

Pregnancy during adolescence may increase the risk of overweight/obesity. There is evidence that increasing calcium intake, alone or vitamin D-combined, may favor loss of weight and/or fat mass.

We hypothesized that calcium supplementation during pregnancy reduces excessive fat accumulation during postpartum period. We aimed to investigate the effect of calcium plus vitamin D supplementation during pregnancy on body composition measurements throughout 1 year postpartum in Brazilian adolescents with habitually low calcium intake (~600 mg/day).

Adolescents (14-19 years) were randomly assigned to receive a daily supplement (600 mg of calcium plus 200 UI of cholecalciferol, n = 30) or a placebo (n = 26) from 26 weeks of gestation until parturition. Body composition was determined at 5, 20, and 56 weeks postpartum by dual-energy x-ray absorptiometry. The effects of intervention group, time point, as well as their interaction were assessed using repeated measures mixed-effects models.

In the adjusted analysis, those supplemented showed lower total body mass [mean difference = -3.32 kg; confidence interval (CI) 95% -6.12 to -0.52 kg], trunk (-1.25 kg; CI 95% -2.34 to -0.15 kg), android (-0.29 kg; CI 95% -0.53 to -0.04 kg) and subcutaneous (-0.23 kg; CI 95% -0.43 to -0.03 kg) fat masses. In the supplemented group, BMI and postpartum weight retention significantly decreased from 5 to 20 weeks (-0.90 kg/m² and -1.76 kg, respectively; p < .05). At 56 weeks, BMI was still lower (-1.22 kg/m² ; p < .05) than 5 weeks.

Our findings suggest that increasing calcium intake through supplementation in combination with vitamin D contributes to a more pronounced reduction in total body mass overtime, mostly as a consequence of fat mass reductions in central body regions. This trial was registered at clinicaltrials.gov as NCT01732328.