High prevalence of genu varum/valgum in European children with low vitamin D status and insufficient dairy products/calcium intakes

Objective: The prevalence of lower limb deformities physiologically decreases after 5 years of age. It remains high in some tropical and subtropical regions where it has been associated with severe vitamin D deficiency, low calcium/milk intakes, malnutrition, and/or fluoride overexposure. Very little data is available in apparently healthy Caucasian children and adolescents. Design: We evaluated the prevalence of genu varum/valgum and other clinical symptoms, and assessed vitamin D status and markers of calcium metabolism in 226 apparently healthy European full-time boarders (7-16 years) seen during winter-spring and fed a cereal-based diet with little access to meat, milk, and dairy products. A cohort of 71 white children and adolescents hospitalized for acute illness served as age-matched controls. Results: Association studies showed a high prevalence of lower limb deformities (36%) and higher alkaline phosphate activities in the 21% of children and adolescent full-time boarders with serum 25-(OH) D levels <= 30 nmol/l, and low serum calcium in the 74% of boarders with 25-(OH) D levels <= 50 nmol/l, compared with boarders with higher vitamin D status. No such anomalies were found in the control cohort despite lower serum 25-(OH) D levels. Conclusions: Low 25-(OH) D levels, at least during winter-spring, combined with additional risk factors such as very low calcium/milk intakes and possibly digestive disorders, are associated with an increased risk of genu varum/valgum in European children and adolescents. Thus, dietary fortification, or supplementation with vitamin D, may be recommended, at least during the winter, to European children and adolescents with either none or insufficient calcium/dairy product intakes.