Bone Abstracts

Objective: Nutritional rickets in Nigerian children is primarily due to dietary calcium deficiency and heals with calcium supplementation. Our aim was to determine the optimal dose of calcium for treatment of children with rickets due to dietary calcium deficiency.

Methods: At the Jos University Teaching Hospital, 65 Nigerian children with radiographically-confirmed rickets were randomized to daily supplemental calcium intake of 500 mg (n=21), 1000 mg (n=23), or 2000 mg (n=21). Venous blood, radiographs, and forearm bone density (BMD) were obtained at baseline and at 8, 16, and 24 weeks after enrollment. The primary outcome was radiographic healing, assessed with a 10-point radiographic score (score of 10 represents the most severe rickets, and 1.5 or less is considered healed).

Results: The radiographic severity scores improved in all three groups over 24 weeks, but the rate of radiographic healing differed significantly between groups. The 1000 and 2000 mg supplementation groups improved significantly more rapidly (P<0.001) than the 500 mg supplementation group during treatment (Figure 1). The 2000 mg group did not heal more rapidly than the 1000 mg group. After 24 weeks, 12 (67%), 20 (87%), and 14 (67%) in the 2000, 1000, and 500 mg groups respectively, had achieved a radiographic score of 1.5 or less (P=0.21). Alkaline phosphatase decreased and serum calcium increased at similar rates in all groups. The forearm diaphyseal BMD improved significantly more rapidly in the 2000 and 1000 mg groups than in the 500 mg group (P<0.001).

Conclusion: Daily calcium intakes of 1000 or 2000 mg were superior to 500 mg for radiographic healing of rickets, but 2000 mg did not improve radiographic scores more rapidly than 1000 mg.

Disclosure: The authors declared no competing interests.

Figure 1 Radiographic scores during treatment of nutritional rickets with three different doses of calcium supplements