Objective: To evaluate serum 25-hydroxyvitamin D levels, demographic features, and anthropometric measurements at the first manifestation of disease in children and adolescents with multiple sclerosis (MS).

Methods: This retrospective study included patients with MS and healthy children and adolescents. Children and adolescents whose clinical and radiological findings were compatible with the McDonald 2017 criteria and who had vitamin D results during the first relapse were included. Having an acute or chronic disease was an exclusion criterion for healthy controls. Taking a supplementation including vitamin D is an exclusion criterion for both the MS and control groups. Age, gender, anthropometric measurements, and serum levels of 25-hydroxyvitamin D were extracted from the database.

Results: A total of 23 patients (female: 17, 73.9%) and 24 (female: 12, 50.0%) healthy children and adolescents were included. The median ages of the patient group and the control group were 16.33 (2.00), and 15.36 (2.29), respectively. There were no significant differences between the groups in terms of age, gender, weight-standard deviation score (SDS), height-SDS, and body mass index-SDS. Precisely, 87.0% of the patients had a vitamin D deficiency. The mean vitamin D values of the patients and the healthy controls were 12.76±5.52, and 18.75±5.86, respectively. Patients with MS had significantly lower levels of 25-hydroxyvitamin D than healthy controls (p<0.0001).

Conclusion: The current study showed that most (87.0%) of the children and adolescents had vitamin D deficiency at the first manifestation of MS. Moreover, the levels of 25-hydroxyvitamin D levels were significantly lower in patients with MS than in the healthy controls.

Keywords: Multiple sclerosis, vitamin D, 25-hydroxyvitamin D, children, adolescents, the first manifestation, height