Vitamin D, Chronic Migraine and Extracranial Pain: Is there a Link? Data from an Observational Study.

Abstract

Background: Several studies focused on the possible role of vitamin D (vitD) in pain chronicization.. The aim of this study was to assess the potential implications of VitD deficit on headache characteristics and extracranial pain extension.Methods: Eighty consecutive patients with primary headache underwent neurological examination, laboratory exams including serum calcifediol 25(OH)D and headache features assessment along with three questionnaires investigating depression, anxiety and allodynia. Results: The 82.6% of the population had migraine (48% episodic and 52% chronic form). The 45% of patients had extracranial pain and 47% suffered from allodynia. In the 45% of patients had a VitD deficit since the serum 25(OH)D levels fell below the cut-off level of 20 ng/ml. The occurrence of VitD deficit was significantly higher (p=0.009) in patients suffering from chronic migraine (CM)- medication overuse migraine (MOH) (64.7%) than in episodic migraine (EM) or tension type headache (TTH). The occurrence of subjects with extracranial pain and allodynia was higher, as expected, in the CM-MOH than in the EM and in the TTH groups but was not related to the co-occurrence of vit-D deficiency (Fischer’s exact test p=0.11 and p=0.32 respectively).Conclusions: Our findings show that 25(OH)D deficit is related to chronic pain suggesting that vitD probably has anti-inflammatory and tolerogenic properties, rather than a direct antinociceptive effect, and reinforce the idea of a neuroinflammatory mechanisms underpinning migraine chronicization.