Vitamin D and Migraine
Vitamin D deficiency is more common in migraine sufferers than in age-matched controls, and smaller controlled trials of supplementation have reported reduced attack frequency. It's a reasonable low-cost adjunct — likely most helpful when baseline 25(OH)D is genuinely low.
The evidence base
- Ghorbani 2020 (Iran RCT) — 80 adults with episodic migraine; 2,000 IU/day for 12 weeks reduced monthly headache days from ~7 to ~3 (placebo went from 7 to 5.5).
- Buettner 2015 (VITAL-migraine) — post-hoc analysis; no effect of 2,000 IU cholecalciferol/day on migraine incidence in adults not selected for deficiency.
- Cayir 2014 (children) — vitamin D repletion in deficient children with migraine reduced monthly attack days.
- 2019 meta-analysis of 8 RCTs — pooled reduction of ~1.5 headache days per month; effect largest in deficient subgroups.
Mechanism
Vitamin D modulates central nociception, cortical excitability, and inflammatory cytokines implicated in migraine (IL-6, TNF-α). Migraine is now understood as a neuroinflammatory disorder; vitamin D's immunomodulatory effects are biologically plausible.
Stacking with other supplements
The American Academy of Neurology gives Level B evidence to riboflavin 400 mg/day, magnesium 400–600 mg/day, and CoQ10 300 mg/day for migraine prevention. Vitamin D isn't on that list yet — the trials are smaller — but there's no interaction and no reason not to combine them. Allow 8–12 weeks to judge effect.
Practical guide
- Test 25(OH)D. If < 20 ng/mL, correct with 2,000–4,000 IU/day.
- If already 30–50 ng/mL, expect only a small additional benefit at best.
- Track a headache diary before and 3 months into supplementation to judge effect.
- Combine with proven prophylaxis — riboflavin, magnesium, CoQ10, or prescription options — rather than substituting.