Low intake of vitamin B6 is associated with irritable bowel syndrome symptoms

Most subjects with irritable bowel syndrome (IBS) experience an association between symptoms and food consumption. Although dietary intake has been the focus of previous research, attention to specific nutrients has been rare. We hypothesized that there is an association between the severity of IBS symptoms and the intake of specific food groups and specific nutrients. In this cross-sectional study, 17 human subjects with IBS, as defined according to the Rome II criteria, were recruited. IBS symptoms were recorded on diary cards every evening for 7 days, and an IBS sum score was calculated (range, 0-15). Intake of food was assessed from a food diary kept by the subjects in the same period. Associations between IBS sum score and dietary intake were explored. The daily IBS sum score was 6.43 (range, 3.86- 9.09). Intake of vitamin B₆ was the only component of the diet that was significantly associated with the IBS sum score. The median daily intake of vitamin B₆ was 0.9 mg/day (range, 0.6-1.5), the recommended daily intake for men and women is 1.6 mg/day or more and 1.2 mg/day or more, respectively. A high symptom score was associated with low vitamin B₆ intake (adjusted R² = 0.583; β = -4.431; 95% confidence interval, -6.386 to -2.476; P = 0.0002). A significant inverse association between intake of vitamin B₆ and severity of IBS symptoms might have clinical implications.