There are two stages of vital importance in bone development (gestation and lactation) and any modification in these periods would cause a greater risk of pathologies in later life. Bone turnover process begins in uterus, during the early stages of pregnancy, to ensure proper foetal development and suitable mineral content to protect the skeleton of the neonate. The role of DHA in bone health is a relatively new subject of study and taking into account these considerations, the aim of this study was to evaluate for the first time the effect of DHA supplementation during pregnancy and lactation on bone metabolism in mother and their neonates. 110 pregnant women were divided in two groups: control group (400 mL/day of the control dairy drink); supplemented group (400 mL/day of the fish oil enriched dairy drink). After delivery blood samples were collected from the umbilical artery and also at 2.5 months of life a sample of blood form all the neonates was obtained. In neonates, DHA supplementation increased ACTH, insulin, leptin and OC, diminishing PTH. In umbilical artery, DHA supplementation increased OPG and leptin and diminished TNF-α. It has been reported that ACTH may stimulate osteoblast proliferation through specific receptors on these cells, which would enhance bone formation. Leptin has a double mechanism on bone metabolism, stimulating bone formation and also improves bone strength. Therefore, DHA supplementation during pregnancy and lactation has beneficial effects on bone turnover in the mothers and their neonates, being the most noteworthy effect recorded in the neonate at 2.5 months of postnatal life.