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.