130 PLASMA OSTEOCALCIN LEVELS IN VITAMIN D DEFICIENCY RICKETS

Abstract

In order to evaluate the interest of osteocalcin, which is synthetized in bone concomitant with the appearance of mineralized bone, we studied 20 infants aged 7 to 15 months with vitamin D deficiency rickets, before and after treatment (1000 mg/m2 calcium and 2.5 mg vitamine D). Serum alkaline phosphatases (ALP) levels, bone and liver isoenzymes, were measured by Bio Merieux Kit, isoenzymes by cellulose acetate electrophoresis; 25 and 1.25 dihydroxy vitamin D were measured according to Shepard method; intact parathyroid hormon by Nichols kit. Before treatment to the serum osteocalcin and vitamin D metabolites levels were lower in infants with rickets than in control subjects. A significant change and rise was observed as soon as 1 week after treatment. In contrast, ALP and its bone isoenzyme levels were elevated before treatment and did not change significantly over 4 weeks, and secondary hyperparathyroidism was reduced after 2 or 3 weeks. To conclude osteocalcin appears to be an early indicator of bone response to treatment in vitamine D deficiency rickets and its low level before treatment might be due to decreased vitamine D metabolites levels rather than hyperparathyroidism.