The association of vitamin B
levels with depressive and non-depressive symptoms, and with the severity of depressive symptoms based to BDI scores. A: The association of vitamin B12 levels with the non-melancholic or the melancholic depressive symptoms and the non-depressive symptoms. B: The association of vitamin B12 levels with severity of the non-melancholic and the melancholic depressive symptoms according to the BDI-scores. C: Non-linear quadric model of the vitamin B12 levels versus BDI score. Model adjusted using age, sex, use of antidepressive medication and chronic diseases. The gray band gives the 95% confidence intervals. BDI, Beck Depression Inventory; NmDS, non-melancholic depressive symptoms; MDS, melancholic depressive symptoms.