Association between dietary calcium to Phosphorus Ratio and the odds of ulcerative colitis: A case-control study

Background & aims: Ulcerative colitis (UC) is a recurrent, inflammatory, autoimmune intestinal disease. The dietary calcium to phosphorus (Ca:P) ratio is suggested to affect the inividuals' normal metabolic and inflammatory pathways. The present study aimed to investigate the association between dietary Ca:P ratio and the odds of developing UC in a case-control format. Methods: The study included sixty-two currently diagnosed UC patients and one hundred twenty-four matched controls, designed as a case-control study. The dietary intakes of the participants were assessed by a food frequency questionnaire (FFQ), and the dietary Ca:P ratio was calculated. The association between tertiles of Ca:P ratio and UC was examined using the logistic regression. P-values <0.05 were considered as significant. Results: The study sample consisted of participants with an average age of 36.63 +/- 12.42 years and a mean body mass index (BMI) of 25.39 +/- 3.82 kg/m(2). The overall energy-adjusted ratio of Ca:P was 0.74 +/- 0.11. In the multivariate model, after adjustment for potential confounders, participants in the third tertile of dietary Ca:P ratio had a lower odds of developing UC compared to the lowest tertlie (OR: 0.34, 95% CI: 0.13-0.87; p = 0.026). Conclusion: Our results indicate that a higher ratio of dietary Ca:P ratio might be protective against developing UC. However, further studies are warranted to examine this association in various populations.