Vitamin C is a notable dietary nutrient critical to numerous physiologic processes. Unlike most animal species, humans are unable to produce vitamin C de novo and must acquire it through the diet, leaving the fate of many biological processes contingent on dietary availability. Recent work has discovered an important role for vitamin C in promoting DNA and histone demethylation by serving as a cofactor for ten-eleven translocation (TET) methylcytosine dioxygenases and JmjC domain-containing demethylases. DNA and histone methylation dynamics have critical implications for health and disease, particularly in neurological development and the etiology of neuropathologies. Therefore, vitamin C may influence neurological development and disease states through its function in promoting demethylation. Vitamin C has previously been linked to neural progenitor differentiation, neurotransmitter synthesis, and neuronal activity. This chapter reviews the role of vitamin C in neuronal processes and explores how its role in DNA demethylation may impact neuronal function.