To examine the association between dietary folate, riboflavin, vitamin B-6, and vitamin B-12 and depressive symptoms in a group of adolescents.
This cross-sectional study, conducted in all public junior high schools in Naha City and Nago City, Okinawa, Japan, included 3,067 boys and 3,450 girls aged 12 years to 15 years (52.3% of eligible sample). Dietary intake was assessed using a validated, self-administered diet history questionnaire. Depressive symptoms were defined as present when participants had a Center for Epidemiologic Studies Depression Scale score of ≥16.
The prevalence of depressive symptoms was 22.5% for boys and 31.2% for girls. Folate intake was inversely associated with depressive symptoms in both boys (adjusted odds ratio (OR) [95% confidence interval (CI)] in the highest (compared with the lowest) quintile, 0.60 [0.45, 0.79]; p for trend = .002) and girls (OR [95% CI], 0.61 [0.48, 0.77]; p for trend = <.001). Vitamin B-6 intake was inversely associated with depressive symptoms in both boys (OR [95% CI], 0.73 [0.54, 0.98]; p for trend = .02) and girls (OR [95% CI], 0.72 [0.56, 0.92]; p for trend = .002). Riboflavin intake was inversely associated with depressive symptoms in girls (OR [95% CI], 0.85 [0.67, 1.08]; p for trend = .03), but not in boys. No clear association was seen between vitamin B-12 intake and depressive symptoms in either sex.
This study suggests that higher intake of dietary B vitamins, particularly folate and vitamin B-6, is independently associated with a lower prevalence of depressive symptoms in early adolescence.
BDHQ = brief self-administered diet history questionnaire; CES-D = Center for Epidemiologic Studies Depression Scale; CI = confidence interval; DHA = docosahexaenoic acid; EPA = eicosapentaenoic acid; OR = odds ratio; RYUCHS = Ryukyus Child Health Study.
From the Department of Social and Preventive Epidemiology (K.M., S.S.), School of Public Health, University of Tokyo, Tokyo, Japan; Department of Public Health (Y.M., K.T.), Faculty of Medicine, Fukuoka University, Fukuoka, Japan; and Field Science for Health and Recreation (M.A.), Faculty of Tourism Sciences and Industrial Management, University of the Ryukyus, Okinawa, Japan.
This research was supported, in part, by Health and Labour Sciences Research Grants, Research on Allergic Disease and Immunology from the Ministry of Health, Labour, and Welfare, Japan (Y.M.).
The authors have not disclosed any potential conflicts of interest.
Address correspondence and reprint requests to Kentaro Murakami, PhD, Department of Social and Preventive Epidemiology, School of Public Health, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan. E-mail: firstname.lastname@example.org
Received for publication April 8, 2010; revision received July 1, 2010.