What does a low Folsäure result mean?

A low folate level in blood (serum or red blood cells) indicates insufficient intake or absorption of this B vitamin. Folate is critical for DNA synthesis, cell division, red blood cell formation, and preventing neural tube defects in pregnancy. Causes include poor diet, increased demand (pregnancy, growth), malabsorption (celiac disease, Crohn's), or medications (methotrexate, anticonvulsants). Deficiency leads to megaloblastic anemia, fatigue, and elevated homocysteine – a cardiovascular risk marker. Serum folate reflects recent intake; RBC folate indicates long-term status. Crucially, low folate must be interpreted alongside vitamin B12, as B12 deficiency can cause similar symptoms and high-dose folic acid can mask B12 deficiency, risking neurological damage. The provided context contains no specific genetic data on folate metabolism (e.g., MTHFR variants), so no gene-based conclusions can be drawn. Evidence for these clinical associations is strong (human-strong) based on guidelines and trials. Caveat: Always consult a physician before supplementing; self-treatment may be harmful.