Calcium-induced serum bone Gla protein variations in preterm newborns.

The effect of calcium infusion on osteocalcin(Bone Gla Protein, BGP) serum levels were studied in a group of preterm newborns with bw appropriate for gestational age. Results showed that basal BGP serum levels in preterm newborns are higher than those reported at birth in normal infants. Moreover, calcium infusion induced a significant decrease in BGP values, inversely correlated with serum calcium. Since calcium loading increases both Ca availability for bone formation and BGP affinity for mineral surfaces, reduction of osteocalcin serum levels might reflect a shift of the protein from bloodstream to bone, suggesting an intervention in regulating an effective calcium uptake.