Diet, as well as other lifestyle factors (sleep, exercise etc) are thought to play a significant role in the occurrence of mental disorders, including depression and anxiety. This study focused on the dietary intake of particular minerals (zinc, copper and manganese) and their effects on depression and anxiety of 2089 Japanese participants, each in full time employment. Reasons for the occurrence of mental disorders are considered multi-factorial, but insufficient mineral intake (particularly zinc) is believed to be a causal factor in the prevalence of depression and anxiety. Results of this cross-sectional study showed that low intake of zinc, copper and manganese was associated with depression and anxiety symptoms. More specifically, the effect of both low zinc and low copper intake indicated a higher susceptibility towards depression with both low and high manganese status, suggesting low zinc and copper intake contributes to depression and anxiety symptoms regardless of manganese status. Researchers acknowledge that more investigation is needed.