Study of the Determinants of Vitamin D Status in Pediatric Patients With Osteogenesis Imperfecta.

Vitamin D is essential to the development and maintenance of the skeleton, especially for children with bone disorders such as osteogenesis imperfecta (OI). We evaluated serum 25-hydroxyvitamin D (25-OHD) levels to assess the relationship between determinants of vitamin D status in pediatric patients with OI.

This cross-sectional study evaluated sex, age, weight, height, body mass index, OI type, sunscreen use, season of assessment, sun exposure, vitamin D and calcium supplementation, bisphosphonate treatment, bone mineral density (BMD), milk and soda consumption, mobility, and time of sedentary activity. Levels of serum 25-OHD, calcium, parathyroid hormone (PTH), phosphorus, and alkaline phosphatase (ALP) were analyzed. Serum levels of 25-OHD were classified according to sufficient (>30 ng/ml or 75 nmol/L), insufficient (20-30 ng/ml or 50-75 nmol/L), moderately deficient (20-10 ng/ml or 50-25 nmol/L), and severely deficient (<10 ng/ml or 25 nmol/L).

Fifty-two patients were included and 46 (88.4%) were classified as having insufficient or deficient 25-OHD. An inverse correlation between serum 25-OHD and time of sedentary activity (r = -0.597, p < 0.001) and a positive correlation with height (r = 0.521, p = 0.046) and whole body BMD (r = 0.586, p = 0.022) were observed. A significant difference between the number of glasses of milk consumed (p = 0.010) was observed.

To optimize bone health, patients with OI need to be educated regarding habits that can improve serum 25-OHD levels, such as a reduction in periods of inactivity, the importance of sun exposure, and increasing consumption of milk and fortified dairy products.