Vitamin D supplementation after the second year of life: joint position of the Committee on Nutrition, German Society for Pediatric and Adolescent Medicine (DGKJ e.V.), and the German Society for Pediatric Endocrinology and Diabetology (DGKED e.V.).

Background: Low vitamin D serum concentrations have been associated with rickets and other disorders in observational studies. Since vitamin D serum concentrations in children and adolescents are frequently below reference values, it is debated whether vitamin D should be supplemented after infancy.

Methods: The effects of vitamin D supplementation in children > 2 years of age are analyzed based on a literature review of randomized controlled trials (RCTs).

Results: Vitamin D supplementation can potentially reduce the risk for influenza infections and improve asthma bronchiale exacerbation; however, it has no impact on asthma bronchiale severity. Vitamin D supplementation has no relevant effect on attention-deficit/hyperactivity disorders, cardiac failure, hypertension, or incidence of type II diabetes mellitus. Vitamin D supplementation has no effect on the rate of multiple sclerosis relapses, but on the number of new lesions detected by MRI. For other endpoints, RCTs are lacking.

Conclusion: Based on currently available studies, routine vitamin D supplementation is not be recommended for children aged > 2 years, even when they have serum concentrations below reference values. Routine vitamin D supplementation is not recommended in children who do not have risk factors and chronic diseases which are associated with calcium or vitamin D resorption disorders.