Myths vs facts: Folsäure and sleep

The claim that folic acid (vitamin B9) directly improves sleep is not well supported by scientific evidence. While folate is involved in neurotransmitter synthesis (e.g., serotonin, dopamine) and homocysteine metabolism—both linked to mood and circadian regulation—clinical trials in healthy individuals without deficiency have not shown consistent benefits for sleep quality or duration. Most evidence is mechanistic or observational, with small effect sizes. Additionally, high-dose folic acid can mask vitamin B12 deficiency, potentially delaying diagnosis of neurological damage. Therefore, the idea that folic acid is a sleep aid is more myth than fact. For sleep issues, a medical evaluation for underlying deficiencies or disorders is recommended before supplementing.