Calcium plus vitamin D supplementation during pregnancy protects Brazilian adolescent mothers from excessive bone loss during lactation

We evaluated the influence of calcium plus vitamin D supplementation during pregnancy on bone mass of lactating adolescent mothers (13–19y) with habitually low calcium (655 mg/d) and vitamin D (34 IU/d) intake. Total body (TB) and lumbar spine (L1‐L4, LS) bone mineral content (BMC) and density (BMD) were assessed by DXA at 1 and 4 mo postpartum (PP). Adolescent mothers randomly received daily calcium (600 mg) plus vitamin D 3 (200 IU) supplement (n=30) or placebo (n=25) from 26 wk of gestation until parturition. Comparisons between groups were done using maternal age, height, season and period PP as covariates (ANOVA). At 1 mo PP, supplemented mothers had higher TBBMD (3%, P =0.05), LSBMD (4%, P =0.08), TBBMC (2.4%, P =0.06), and LSBMC (8.5%, P <0.05) than those in the placebo group. At 4 mo PP, differences between groups were more pronounced, with higher TBBMD (4.3%, P< 0.05), LSBMD (5.9%, P <0.05), TBBMC (4.1%, P =0.06) and LSBMC (9.1%, P <0.05) in the supplemented group. Our results indicate that calcium plus vitamin D 3 supplementation during pregnancy protects adolescent mothers from excessive bone loss during lactation, especially at the lumbar spine. This protective effect persists at least up to 4 months of lactation. Financial support: CNPq and FAPERJ (Brazil).