Vitamin D status of chronically ill or disabled children in Victoria

OBJECTIVE: To establish the percentage prevalence of hypovitaminosis D in chronically ill or disabled children in Melbourne, Australia. METHODOLOGY: A group of inpatients at the Royal Children's Hospital, Melbourne, Victoria, as identified by the primary unit, were sampled to measure serum vitamin D and parameters of bone turnover. A second group of disabled children (outpatients) were also measured to establish vitamin D status. RESULTS: Of the total population, 54.9% were found to have low serum 25 hydroxy (25OH) vitamin D levels. Of the inpatient group, 25.4% were vitamin D deficient (<30 nM/L), and 27.1% were vitamin D insufficient (30-50 nM/L). The mean 25OH vitamin D was 52.1 nM/L. Of the outpatient group, 15.4% were vitamin D deficient, whilst 42.3% were found to be insufficient. The mean vitamin D level was 41.2 nM/L. No difference attributable to intellectual versus physical disability was found. Anticonvulsant use and ambulatory status was not predictive of vitamin D status in the children examined. Of the total population, 0.05% were found to have secondary hyperparathyroidism. The mean 25OH vitamin D level of this subgroup was 30.6 nM/L. Dark skin tone was found to be significantly associated with hypovitaminosis D (P = 0.001), where all five children with dark skin tone were found to have serum 25OH vitamin D levels <50 nM/L. Of the seven disabled children (outpatients) found to be iron deficient, four had coexistent hypovitaminosis D. CONCLUSION: The percentage prevalence of hypovitaminosis D is high in both chronically ill, and physically/intellectually disabled children in Melbourne, Australia. Increased vigilance and recognition of this deficiency state is needed as an important health prevention strategy.