PTH and irritable bowel syndrome: As shown in Figure 2, genetically predicted risk of IBS was not associated with the levels of vitamin D (p = 0.938, OR = 0.99, 95% CI: 0.83–1.19), calcium (p = 0.248, OR = 0.92, 95% CI: 0.80–1.06), and parathyroid hormone (p = 0.427, OR = 1.04, 95% CI: 0.94–1.15) using the IVW method.