Rickets in Nigerian children: Response to calcium supplementation

In a previous study of rachitic children in Jos, Nigeria we concluded that inadequate dietary intake of calcium was the primary contributing factor to the development of their rickets. The objective of the present study was t o determine the effect of calcium supplementation in 10 children with radio graphically and biochemically proven rickets from the same geographical are a. Rachitic children mere provided with calcium supplements of 1000 mg/day for a period of 3 months. Serum and urine samples were obtained at baseline and at 24 hours, 1 week, 4 weeks, and 12 weeks after initiation of supplem entation, Serum calcium, phosphorus, alkaline phosphatase, intact parathyro id hormone, 25-hydroxyvitamin D, and 1,25-dihydroxyvitamin D were measured at each time point. Dietary recalls obtained at two separate times were use d to estimate usual daily intakes of calcium and phosphorus, Ten non-rachit ic age-matched controls from the same geographical area were recruited for comparison, Nine of 10 rachitic subjects had radiographic evidence of heali ng after 3 months of calcium therapy. Although serum calcium concentrations returned to control levels, other biochemical data indicated that the rick ets of these subjects may have been multifactorial in aetiology, pointing t o a possible defect in the synthesis of 25-hydroxyvitamin D.