Serum concentrations of vitamin D metabolites in rachitic Libyan children.

Twenty-two consecutive patients with rickets were studied in Benghazi, Libya. All were less than 2 years old. Rickets was associated with traditional cultural habits that limited sunshine exposure of the mothers and their infants, and with breast-feeding. Serum concentrations of the vitamin D metabolites 25-hydroxyvitamin D (25-OHD), 1,25-dihydroxyvitamin D, and 24,25-dihydroxyvitamin D, and other parameters of mineral metabolism were typical of vitamin D deficiency disease, as was the biochemical and clinical response to treatment. Minimum safe serum levels of 25-OHD (20 nmol/L), and the serum levels of vitamin D metabolites in response to vitamin D treatment, were identical to previously obtained results from native Norwegian and Norwegian immigrant children with rickets, suggesting lack of racial differences in response to vitamin D. Fifty percent of the patients had adequate levels of vitamin D metabolites at the time of diagnosis, indicating that they had recently received oral vitamin D or cutaneous exposure to sunshine. Many cases of rickets in the area may, therefore, be spontaneously cured when the children's maturity allows adequate mobility and independence to achieve exposure to sunshine.