Persistence of Vitamin D-deficiency rickets in Toronto in the 1990s.

To assess the current picture of vitamin D deficiency, we reviewed all 17 cases of vitamin D-deficiency rikets seen in the referral clinic of a children's hospital in Toronto between 1988 and 1993. The diagnosis was made at 7 to 33 months of age. All the children were symptomatic all had biochemical and radiographic abnormalities, two suffered hypocalcemic seizures, and all had bowing of the extremities. Twelve of the children were born to parents who were recent immigrants to Canada. All were of Asian or African origin with dark skin. All the children had been exclusively breastfed with no vitamin D supplementation, and had had little or no sunlight exposure. All the patients responded to vitamin D therapy. We conclude that vitamin D-deficiency rickets remains an environmental/nutritional deficiency disease in this city and that efforts at prevention should target children with pigmented skin from families who are recent immigrants.