RESUMO
OBJECTIVE: To see the interrelation between chronic tension-type headache (CTTH) and serum vitamin D levels. BACKGROUND: Several studies have suggested an association between chronic pain and vitamin D deficiency. Anecdotal evidence suggests that vitamin D deficiency may be associated with tension-type headache and migraine. METHODS: This case-control study was carried out to examine the association between CTTH and serum 25-hydroxy vitamin (25(OH) D) levels. One hundred consecutive adult (>18 years) patients with CTTH and 100 matched healthy controls were enrolled. RESULTS: The serum 25(OH) D levels were significantly lower in CTTH patients than in the controls (14.7 vs 27.4 ng/mL). The prevalence of vitamin D deficiency (serum 25 (OH) D < 20 ng/mL) was greater in patients with CTTH (71% vs 25%). CTTH patients had a significantly high prevalence of musculoskeletal pain (79% vs 57%), muscle weakness (29%vs 10%), muscle tenderness score (7.5 vs 1.9), and bone tenderness score (3.0 vs 0.8) in comparison to controls. CTTH patients with vitamin D deficient group (<20 ng/mL) had a higher prevalence of musculoskeletal pain (58% vs 31%), muscle weakness (38%vs 7%), muscle and bone tenderness score, associated fatigue (44% vs 17%) and more prolonged course (15.5 months vs 11.2 months). A strong positive correlation was noted between serum vitamin D levels and total muscle tenderness score (R2 = 0. 7365) and total bone tenderness score (R2 = 0. 6293). CONCLUSION: Decreased serum 25(OHD) concentration was associated with CTTH. Intervention studies are required to find out if supplementation of vitamin D is effective in patients with CTTH.