What role does Folsäure play in Schlaf?

The provided context does not contain information on the role of folic acid (vitamin B9) in sleep. Generally, folic acid is involved in homocysteine regulation and neurotransmitter synthesis; a deficiency might indirectly affect sleep via elevated homocysteine or mood disturbances. However, robust clinical evidence directly linking folic acid supplementation to improved sleep quality or duration is lacking. The evidence level is therefore unclear. Supplementation without medical indication is not advised, as excessive intake (especially of synthetic folic acid) may pose risks. A blood test for folate or homocysteine levels is more informative than blanket supplementation.