The relationship of severity of depression with homocysteine, folate, vitamin B12, and vitamin D levels in children and adolescents

Background Depression is a heterogeneous disorder and is thought to develop as a result of complex interactions between genetic and environmental factors. One‐carbon metabolism that includes vitamin B12, folic acid, and homocysteine has been investigated in psychiatric disorders like depression. In recent years, vitamin D has also been considered to contribute to psychiatric disorders. In this study, serum levels of folate, vitamin B12, and homocysteine related to one‐carbon metabolism and vitamin D were investigated in children and adolescents with depression and to assess possible roles in depression pathogenesis. Methods The study included 89 children and adolescents with depression (69 female, 20 male; mean age ± SD = 15.08 ± 1.46) and 43 control subjects (31 female, 12 male; mean age ± SD = 14.41 ± 2.32) without any DSM‐5 diagnosis. Each subject completed a sociodemographic form, Childhood Depression Inventory, State‐Trait Anxiety Inventory 1‐2 and measured serum folate, vitamin B12, homocysteine, and 25‐OH vitamin D levels. Results There was no significant difference between the groups in terms of folate levels ( p = .052). In the patient group, the vitamin B12 and vitamin D levels were clearly low ( p values for both levels were <.001), while homocysteine levels were found to be remarkably high ( p < .001). In addition, there was a negative correlation between depression severity and vitamin B12 and vitamin D, while a positive correlation was found with homocysteine. Conclusions The results of the study show that vitamin B12 deficiency or insufficiency and elevated homocysteine may contribute to the etiopathogenesis of depression. Additionally, it was shown that lower vitamin D levels may be associated with depression. Key Practitioner Message Depression of children and adolescents is associated with the interaction of environmental and genetic factors. Homocysteine, vitamin B12, and folate related to one‐carbon metabolism are associated with psychiatric disorders such as depression in adulthood. Vitamin D also contributes to psychiatric disorders pathogenesis. There are not enough studies in the literature about these parameters in children with depression. Low vitamin B12 and vitamin D levels and increased homocysteine levels may play a role in the pathogenesis of depression in children and adolescents. Investigation of vitamin B12, folate, homocysteine, and vitamin D levels are recommended in children and adolescents with depression.