There is lack of data exploring the association of early life factors and bone mineral density (BMD). The investigators of the present study tried to evaluate the function of BF on adolescent BMD in a cohort prospectively observed since infancy.

A total of 679 infants from an infancy iron deficiency anaemia preventive trial observed till adolescence were studied. Breast and bottle feeding was given weekly from 4 to 12 months. The whole body BMD was evaluated by DEXA at 16 years. The relationship between BF duration and BF as the sole source of milk and adolescent BMD z-score was estimated using linear regression while making adjustments for possible infancy, adolescent, and background confounders.

For a minimum of 6 months, Breastfeeding was found to be the sole source of milk for 26.3% and with supplementation for 36.7%. In the remaining 37%, Breastfeeding was given for less than 6 months.  Breastfeeding as the sole source of milk for six months or more was linked to higher adolescent BMD z-score as compared to Breastfeeding for less than six months while adjusting for covariates (sex, birth length, and gestational age). Mixed Breastfeeding was not considerably associated with adolescent BMD z-score. Adolescent BMD z-score was found to be increased by 0.03 for every 30 days of BF as the sole source of milk.