Associations between dietary intake of B-vitamins and psychological disorders among Iranian women: a cross-sectional study

Abstract

Objective: B-vitamins affect brain function through multiple pathways. Given limited evidence on the relationship between dietary intake of these vitamins and psychological disorders, we examined dietary intake of vitamin B6-9-12 in relation to psychological disorders among Iranian women. Design: Cross-sectional study. Dietary intake was assessed using a valid and reliable FFQ. To assess psychological disorders, we used a version of the Depression Anxiety Stress Scale-21 validated in Iran. Setting: Ten public health centres in southern Tehran, Iran. Participants: A total of 447 female participants aged 20-50 years. Results: The median values of vitamin B-6 (pyridoxine), B-9 (folate) and B-12 (cobalamin) were 1 center dot 30 mg/d, 313 center dot 89 mu g/d and 3 center dot 99 mu g/d, respectively. After adjustment for potential confounders, dietary vitamin B-6 intake was associated with lower odds of depression (OR: 0 center dot 54; 95 CI: 0 center dot 31, 0 center dot 95; P (trend): 0 center dot 03). However, there was a positive association between dietary vitamin B-12 intake with the odds of depression (OR: 2 center dot 05; 95 CI: 1 center dot 17, 3 center dot 60; P (trend): 0 center dot 01) and psychological distress (OR: 2 center dot 00; 95 CI: 1 center dot 17, 3 center dot 41; P (trend): 0 center dot 01). No association was found between vitamin B-9 with any psychological disorders. Conclusions: Women with higher dietary intakes of vitamin B-6 had lower likelihood of depression. However, women with higher dietary intake of vitamin B-12 had higher odds of depression and psychological distress. Future prospective studies in different populations are needed to clarify whether B-vitamin deficiency is a cause or consequence of psychological disorders.