Rationale: B vitamins play essential roles in brain development and functionality; however, the effects of their deficiency during early life on mental health are not thoroughly understood.
Objectives: The objective of this study is to investigate the effects of a maternal deficiency of vitamin B6, B9 (folate), and B12 on behavioral changes in adult offspring.
Methods: Female C57BL/6 J mice were put on a diet lacking vitamin B6, B9, B12, or the above three vitamins from pregnancy to weaning. The growth and developmental characteristics of both the pregnant mothers and offspring were collected. In the adult offspring, the serum levels of neuroactive substances were measured using an enzyme-linked immunosorbent assay. The level of BDNF and dimethylated lysine 9 on histone H3 (H3K9me2) was detected by immunohistochemical staining. In addition, their depressive-like behaviors, anxiety-like behaviors, and sociability were recorded using sucrose preference, a forced swim, social interaction, tail suspension, and open field tests.
Results: The maternal deficiency of the three B vitamins delayed offspring development. Compared to the controls, all of the groups showed decreased serum levels of 5-HT and neuropeptide Y. In the groups with deficiency of B9 or the three B vitamins, there were significant changes in sociability and social novelty preference. In groups with deficiencies in B9, B12, or all three B vitamins, the expression levels of BDNF and H3K9me2 in the hippocampus were significantly decreased.
Conclusions: Maternal deficiencies of the major B vitamins caused changes in social behaviors in adult mice accompanied with epigenetic alterations in the brain and changes in the serum levels of neuroactive substances.
Keywords: B vitamins; BDNF; H3K9me2; Maternal nutrition.