Mood disorders affect more than 500 million people around the world. In the last decade, their prevalence has increased, and many people suffer from nervousness, anxiety, and stress at least once in their lives. The incidence of mood disorders and anxiety increases during perimenopause or under stressful conditions. The social restrictions introduced during the COVID-19 pandemic have significantly increased the normal burden of psychological and psychic disorders. In moderate to severe cases, pharmacological treatment is currently recommended, while in mild disorders, especially in the initial phase, psychological therapy is preferable. It is known that several nutrients are crucial for brain function. Among them, folate (vitamin B9), cyanocobalamin (vitamin B12), and S-adenosyl-L-methionine (SAMe) have been shown to influence various neurobiological processes. Overall, the available evidence suggests that dietary supplementation with folic acid, vitamin B12, and SAMe can be beneficial for people with mild mood disorders.