Low serum 25-hydroxyvitamin D levels in migraine are not related to headache frequency: A case-control study in patients with high-frequency/chronic migraine

Serum 25-hydroxyvitamin D (25[OH]D) concentrations have been shown to be low in patients with migraine, but results are controversial regarding the current role of vitamin D in migraine severity. Using a case-control design, we aimed to evaluate serum 25(OH)D levels in a group of females with high-frequency episodic migraine/chronic migraine (HF/CM) and analyze its association with headache frequency and serum calcitonin gene-related peptide (CGRP) levels. Serum 25(OH)D levels were measured in 97 females with HF/CM (age 48.9 ± 9.4 years) and 146 healthy females (47.4 ± 8.1 years). Participants taking vitamin D supplements were excluded. Serum concentrations of 25(OH)D were determined by electrochemiluminescence (Roche, Germany), and CGRP levels were measured by enzyme-linked immunosorbent assay (Abbexa, UK). Mean 25(OH)D levels in females with HF/CM (median [interquartile range] 19.0 [13.0-24.5] ng/mL) were below the values considered for insufficiency or deficiency and significantly lower than controls (25.0 [19-29.8] ng/mL; p