The effects of vitamin D supplementation on interictal serum levels of calcitonin gene-related peptide (CGRP) in episodic migraine patients: post hoc analysis of a randomized double-blind placebo-controlled trial.

BACKGROUND: Emerging evidence showed promising effects of vitamin D on headaches characteristics. Thus, it seems there is still a need for more researches to clarify the mechanisms by which this vitamin exerts anti-migraine effects. METHODS: The present study was conducted as a 16-week randomized double-blind placebo-controlled trial on 80 episodic migraine patients allocated in 2 parallel groups each consisted of 40 patients who received vitamin D 2000 IU/d or placebo. At baseline and after the intervention completion, headache diaries and migraine disability assessment questionnaire (MIDAS) were used to assess migraine related variables in patients. Also, interictal serum concentration of calcitonin gene-related peptide (CGRP) (as the dominant mediator of migraine pain pathogenesis) was evaluated using ELISA method. RESULTS: The mean (SD) of age in the vitamin D and placebo groups was 37 (8) and 38 (12) years, respectively. ANCOVA test adjusted for baseline values, and confounders showed vitamin D supplementation resulted in a significant improvement in MIDAS score after 12 weeks in the intervention group (21.49 (16.22-26.77)) compared to placebo (31.16 (25.51-36.82) P value: 0.016). Moreover, after controlling for baseline levels, and other variables using ANCOVA, CGRP level was appeared to be significantly lower following vitamin D supplementation (153.26 (133.03-173.49) ng/L) than the patients in the placebo arm (188.35 (167.15-209.54) ng/L) (P value = 0.022). CONCLUSION: According to the current findings, vitamin D supplementation in episodic migraineurs, particularly in those with migraine with aura, may potentially improve migraine headache characteristics and disability probably through attenuating CGRP levels. Therefore, these results could provide a new insight into anti-nociceptive effects of vitamin D; however, more studies are required to confirm our findings. TRIAL REGISTRATION: The trial is registered in the Iranian registry of clinical trials (IRCT) at 11 July 2018, with IRCT code: IRCT20151128025267N6.

Vitamin D3 might improve headache characteristics and protect against inflammation in migraine: a randomized clinical trial.

INTRODUCTION: Due to anti-inflammatory effects of vitamin D3, we aimed to explore the effects of supplementation with this vitamin on headache characteristics and serum levels of pro/anti-inflammatory markers in migraineurs. METHODS AND MATERIALS: This placebo-controlled, double-blind study included 80 episodic migraineurs who randomly assigned into two equal groups to receive either daily dose of vitamin D3 2000 IU (50 µg) or placebo for 12 weeks. At baseline and after the trial, headache characteristics were determined using diaries and serum levels of interleukin (IL)-10, IL-6, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (Cox-2) were assessed via ELISA method. RESULTS: At the end of trial, analysis of covariance (ANCOVA) adjusted for baseline values, and confounders revealed that vitamin D3 supplemented group experienced significantly lower headache days per month (4.71), reduced attacks duration (12.99 h/attack), less severe headaches (5.47, visual analog scale), and lower analgesics use/month (2.85) than placebo group (6.43, 18.32, 6.38 and 4.87, respectively) (P values < 0.05). Using ANCOVA adjusted for baseline levels and confounding variables, it was found that serum levels of IL-10 and Cox-2 did not significantly differ between groups after the experiment; whereas, iNOS serum level was significantly reduced in the intervention group (106.06 U/L) comparing to the controls (156.18 U/L P : 0.001). Also, the patients receiving vitamin D3 yielded a marginally significant lower IL-6 serum concentration (76.43 ng/L) compared to placebo (93.10 ng/L) (P value:0.055). CONCLUSION: Based on the results of this study, we found that 2000 IU (50 µg)/day vitamin D3 supplementation for 12 weeks could improve headache characteristics and might reduce neuro-inflammation in episodic migraine.

Vitamin D in migraine headache: a comprehensive review on literature.

INTRODUCTION: As a primary headache, migraine has been established as the first leading disability cause worldwide in the subjects who aged less than 50 years. A variety of dietary supplements have been introduced for migraine complementary treatment. As an anti-inflammatory and antioxidant agent, vitamin D is one of these agents which has been of interest in recent years. Although higher prevalence of vitamin D deficiency/insufficiency has been highlighted among migraineurs compared to controls, there is not any consensus in prescribing vitamin D in clinical practice. Therefore, in the current review, in addition to observational and case-control studies, we also included clinical trials concerning the effects of vitamin D supplementation on migraine/headache. METHODS: Based on a PubMed/MEDLINE and ScienceDirect database search, this review study includes published articles up to June 2019 concerning the association between migraine/headache and vitamin D status or supplementation. RESULTS: The percentage of subjects with vitamin D deficiency and insufficiency among migraineurs and headache patients has been reported to vary between 45 and 100%. In a number of studies, vitamin D level was negatively correlated with frequency of headaches. The present findings show that supplementation with this vitamin in a dose of 1000-4000 IU/d could reduce the frequency of attacks in migraineurs. CONCLUSION: It seems a high proportion of migraine patients might suffer from vitamin D deficiency/insufficiency. Further, the current evidence shows that in addition to routine drug therapy, vitamin D administration might reduce the frequency of attacks in migraineurs. However, these results have yet to be confirmed.