Hypocalcemia and Vitamin D Deficiency amongst Migraine Patients: A Nationwide Retrospective Study.

Background and Objectives: Inadequate vitamin D and calcium intake have been linked to many health issues including chronic headaches. Some studies suggested an association between low vitamin D levels and increase the risk of frequent headaches in middle-aged and older men; however, no single study reported the role of these deficiencies in migraine patients. We aimed to investigate the association of hypocalcemia and vitamin D deficiency with migraine hospitalizations. Materials and Methods: A population-based retrospective cross-sectional analysis of the Nationwide Inpatient Sample (NIS) (years 2003-2014) in migraine hospitalizations was performed. The prevalence, demographic characteristics and All Patient Refined Diagnosis Related Groups severity/disability association were compared in patients with hypocalcemia and vitamin D deficiency to those without deficiencies, using ICD-9-CM codes. Weighted analyses using Chi-Square, paired Student's t-test, and Cochran-Armitage trend test were performed. Survey logistic regression was performed to find an association between deficiencies and migraine hospitalizations and deficiency induced disability amongst migraineurs. Results: Between years 2003 and 2014, of the total 446,446 migraine hospitalizations, 1226 (0.27%) and 2582 (0.58%) presented with hypocalcemia and vitamin D deficiency, respectively. In multivariable analysis, hypocalcemia [Odds Ratio (OR): 6.19; Confidence Interval (CI): 4.40-8.70; p < 0.0001] and vitamin D deficiency (OR: 3.12; CI: 2.38-4.08; p < 0.0001) were associated with markedly elevated odds of major/extreme loss of function. There was higher prevalence (3.0% vs. 1.5% vs. 1.6%; p < 0.0001) and higher odds of migraine among vitamin D deficiency (OR: 1.97; CI: 1.89-2.05; p < 0.0001) patients in comparison to patients with hypocalcemia (OR: 1.11; CI: 1.03-1.20; p = 0.0061) and no-deficiency, respectively. Conclusions: In this study, we demonstrated a significant association between hypocalcemia and vitamin D deficiency with migraine attacks and deficiency induced loss of function among migraineurs. Early preventive measures may reduce the disability in migraineurs.