(P18-018-23) Lactation in Adolescence and Bone Health: A Scoping Review of the Literature

Objectives: In low-middle income countries (LMIC), 7.3 million babies are born annually to adolescents, who are in peak bone mass accrual; however, there is limited evidence on the impact of lactation in adolescence on bone health. We aimed to conduct a scoping literature review to examine: 1) the association of adolescent lactation on bone health, and 2) the effects of perinatal calcium (Ca) and/or Vitamin D supplementation in adolescents on bone health.

Methods: Databases and gray literature were searched in December 2022 using search terms related to adolescence (age < 20), lactation, bone health, and Ca/Vit D supplementation. For Aim 1, we included observational studies with an exposure of lactation in adolescence and any subsequent bone health outcomes. For Aim 2, we included randomized controlled trials (RCTs) of perinatal Ca/Vit D supplementation in adolescents reporting bone health outcomes.

Results: We identified 9 studies of lactation in adolescence and subsequent bone health, all from high or upper-middle income countries. Aim 1) Seven observational studies were identified that reported the association between adolescent lactation and bone health outcomes, though most were heterogeneous and of small sample size. Of 7 studies, 2 showed negative associations between adolescent lactation and bone health outcomes, while 5 showed no association. Aim 2) Two RCTs reported on effects of perinatal Ca/Vit D intake or supplementation in lactating adolescents on bone health (both n < 60). Trial interventions, comparators, and outcome measures differed. One trial compared prenatal Ca 600 mg/d & Vit D 200 IU/d to a placebo, finding significantly higher bone mineral density (BMD) and content (BMC) at 5 & 20 weeks postpartum in the Ca/Vit D group, though not at 1 year postpartum. The other compared a postnatal 1000 mg/d Ca supplement to an equivalent daily intake of Ca via dairy products, finding no difference in BMC or BMD between groups.

Conclusions: The effects of lactation in adolescence on long term maternal bone health are unclear. We found only one placebo-controlled trial of Ca/Vit D supplementation in this population, showing some short term benefits though no sustained effects. Additional research is needed with long term follow up and in LMIC populations with high prevalence of Ca/Vit D deficiency.

Funding Sources: Brigham & Women’s Hospital, Dept of Pediatric Newborn Medicine