Higher Serum Levels of Vitamin D Are Associated With a Reduced Risk of Diverticulitis

BACKGROUND & AIMS: Recent studies have shown geographic and seasonal variations in hospital admissions for diverticulitis. Because this variation parallels differences in ultraviolet light exposure, the most important contributor to vitamin D status, we examined the association of prediagnostic serum levels of vitamin D with diverticulitis. METHODS: Among patients within the Partners Healthcare System who had blood drawn and serum levels of 25-hydroxyvitamin D (25-[OH]D) measured, from 1993 through 2012, we identified 9116 patients with uncomplicated diverticulosis and 922 patients who developed diverticulitis that required hospitalization. We used multivariate logistic regression to estimate relative risks and 95% confidence intervals to compare serum 25(OH)D levels between these groups. RESULTS: Patients with uncomplicated diverticulosis had significantly higher mean prediagnostic serum levels of 25(OH)D (29.1 ng/mL) than patients with diverticulitis who required hospitalization (25.3 ng/mL; P < .0001). Compared with patients in the lowest quintile of 25(OH)D, the multivariate-adjusted relative risk for diverticulitis hospitalization was 0.49 (95% confidence interval, 0.38-0.62; P for trend < .0001) among patients in the highest quintile of 25(OH)D level. Compared with patients with uncomplicated diverticulosis, the mean level of 25(OH)D was significantly lower for patients with acute diverticulitis without other sequelae (25.9 ng/mL; P < .0001; n = 594), for patients with diverticulitis with abscess (25.8 ng/mL; P = .0095; n = 124), for patients with diverticulitis requiring emergent laparotomy (22.7 ng/mL; P = .002; n = 65), and for patients with recurrent diverticulitis (23.5 ng/mL; P < .0001; n = 139). CONCLUSIONS: Among patients with diverticulosis, higher prediagnostic levels of 25(OH)D are associated significantly with a lower risk of diverticulitis. These data indicate that vitamin D deficiency could be involved in the pathogenesis of diverticulitis.