Is Folsäure useful for skin aging?

The provided context contains no direct evidence on folic acid for skin aging. Generally, folic acid (vitamin B9) is crucial for DNA repair and cell turnover, processes relevant to skin health. Some observational studies and small trials suggest potential benefits for photoaged skin, possibly via improved collagen synthesis or reduced oxidative stress. However, the evidence is mostly mechanistic or from animal models; robust human RCTs are lacking. Over-supplementation (especially synthetic folic acid) carries risks, such as masking B12 deficiency. No specific dosage for skin aging exists. Consumers should not rely solely on folic acid; a holistic approach including sun protection, antioxidants, and balanced nutrition is better supported. Evidence is rated 'unclear'.