Contributions of sunshine deprivation and maternal vitamin D deficiency to rickets in the United Arab Emirates

The aims were to better characterize the clinical and biochemical features of rickets and to asses the contributions of sunshine deprivation to maternal vitamin D status and thus its relation to rickets in the child. The clinical and biochemical characteristics of 40 consecutive rachitic children and the sunshine exposure and vitamin D status of their mothers at Al-Ain, United Arab Emirates were studied. Rachitic children had significant skeletal deformities, growth and motor developmental delay; and all had vitamin D deficiency. Clinical features of children with "moderate/severe" vitamin D deficiency (serum 25-OHD 12.5-37.5 nmol/L) were similar to those with "very severe" vitamin D deficiency (<12.5 nmol/L). The median serum alkaline phosphatase concentration was higher in the latter. Sixteen mothers (40%) had "very severe" vitamin D deficiency and 68% were not exposed to sunlight. Maternal body surface area exposed to sunlight correlated with serum 25-OHD concentrations (r=0.48, p=0.002). Rickets was mainly due to severe vitamin D deficiency rickets. Maternal vitamin D deficiency due to sunshine deprivation may contribute to persistence of rickets. Maternal sunshine exposure that ensures adequate vitamin D status should be emphasized in the strategies to eliminate rickets.