DNA synthesis, cell division, blood formation and one-carbon metabolism.
Switzerland age 18–65: 330 µg DFE/day; pregnancy and preconception have specific recommendations.
Leafy greens, legumes, asparagus, citrus, liver and fortified foods.
Megaloblastic anaemia with fatigue, weakness, breathlessness, palpitations and tongue/mouth changes.
Low folate around conception increases neural-tube-defect risk in the baby.
Skin, hair or nail changes are possible but not specific.
Pregnancy, alcohol dependence, malabsorption, very limited diets and some medicines.
Consider full blood count, folate and always vitamin B12 as well.
Folic acid before and early in pregnancy is an established exception to food first; dose according to official guidance.
High folic-acid doses can mask B12 deficiency in the blood count while nerve injury progresses.