Pediatric Headache Patients Are at High Risk of Vitamin D Insufficiency.

Background: Vitamin D deficiency has been associated with headaches in adults, but data for children with headaches are sparse.

Objective: To describe vitamin D levels in children with headaches.

Methods: We retrospectively analyzed serum 25(OH)D concentrations in children aged 2-17 years with headaches compared to children with epilepsy at the Children's Hospital of Eastern Ontario between October 1, 2014, and August 19, 2021. Serum 25(OH)D <50 nmol/L was classified as insufficient.

Results: Vitamin D concentrations of 353 children (117 with headaches; 236 with epilepsy) were analyzed. The median age in years was 10 (interquartile range [IQR] 5, 14); 50.4% of subjects were female. The median serum 25(OH)D was 56 nmol/L (IQR 41, 69) in children with headaches and 70 nmol/L (IQR 50, 95) in children with epilepsy. Vitamin D insufficiency was present in 42% of children with headaches and 25% of children with epilepsy (= .002). In a multivariable linear regression model adjusting for age, sex and seasonality, children with headaches had serum 25(OH)D concentrations that were on average 9 nmol/L (95% CI-16.76, -0.96) lower compared to children with epilepsy (= .029).

Conclusion: The prevalence of vitamin D insufficiency is higher in children with headaches compared to children with epilepsy. Prospective studies are needed to assess if vitamin D supplementation may have a therapeutic effect on pediatric headaches.