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Varying Role of Vitamin D Deficiency in the Etiology of Rickets in Young Children vs. Adolescents in Northern India

2003; Oxford University Press; Volume: 49; Issue: 4 Linguagem: Inglês

10.1093/tropej/49.4.201

1465-3664

K. Balasubramanian, Jithine Jayakumar Rajeswari, Gulab, Y. C. Govil, Agarwal Ak, Anil Kumar, Vijay Lakshmi Bhatia,

Bone health and osteoporosis research

The relative importance of calcium vs. vitamin D deficiency in the etiology of nutritional rickets in the tropics may be different in children compared with adolescents. We studied calcium intake, sun exposure, serum alkaline phosphatase, and 25 hydroxyvitamin D in 24 children and 16 adolescents with rickets/osteomalacia. The values were compared with those obtained in control subjects (34 children and 19 adolescents). We found that young children with rickets had lower calcium intake compared with controls (285 ± 113 vs. 404 ± 149 mg/day, p < 0.01), but similar sun exposure (55 ± 28 vs. 56 ± 23 min·m2/day) and 25 hydroxyvitamin D (49 ± 38 vs. 61 ± 36 nmol/l). Sixteen of 24 children with rickets had 25 hydroxyvitamin D above the rachitic range (> 25 nmol/l), in contrast to one of 16 adolescents. Adolescent patients had low calcium intake vs. controls (305 ± 196 vs. 762 ± 183 mg, p < 0.001), and lower sunshine exposure (16 ± 15 vs. 27 ± 17 min·m2/day, p < 0.01) and serum 25 hydroxyvitamin D (12.6 ± 7.1 vs. 46 ± 45.4 nmol/l, p < 0.001). The odds ratio for developing rickets with a daily calcium intake below 300 mg was 4.8 (95 per cent CI, 1.9 – 12.4, p = 0.001). Subjects with rickets were randomized to receive 1 g calcium daily, with or without vitamin D. Children showed complete healing in 3 months, whether they received calcium alone or with vitamin D. Adolescents showed no response to calcium alone, but had complete healing with calcium and vitamin D in 3–9 months (mean 5.3 months). Thus deficient calcium intake is universal among children and adolescents with rickets/osteomalacia. Inadequate sun exposure and vitamin D deficiency are important in the etiology of adolescent osteomalacia.