Characteristics of Children with Florid Vitamin D Deficient Rickets in the Auckland Region in 1998

Aim: To describe the characteristics of children with vitamin D deficiency rickets and identify common features and predisposing factors.

Methods: A review of the clinical notes of all children less than five years of age with radiological evidence of rickets and serum 25-hydroxyvitamin D levels of less than 10 micrograms/L. Patients were identified by searching all low vitamin D levels performed at the Endocrinology laboratory at Auckland Hospital and children presenting to the Starship Childrens' Hospital with rickets in 1998.

Results: In 1998, there were eighteen children (ten males and eight females) with vitamin D deficient rickets. The age range was 3 to 36 months with a median of 12 months. There were twelve children of Indian ethnic origin, one Maori, one Tongan, one Western Samoan, one Ethiopian, one Moroccan and one Indonesian. All children had an elevated alkaline phosphatase level and most had very low serum 25-hydroxyvitamin D levels (< or = 5 micrograms/L), and over half were hypocalcaemic. The common presenting features were delayed walking and bowed legs, swollen wrists or ankles, hypocalcaemic seizure, incidental radiological abnormalities and failure to thrive.

Conclusions: There are a significant number of children in Auckland presenting with florid clinical rickets. The majority with vitamin D deficient rickets in this survey were of Indian ethnic origin. Strategies are needed to detect children at risk of vitamin D deficiency and supplement them with vitamin D.