B-vitamin for DNA synthesis and healthy red cells; critical pre-pregnancy.
What it is
Serum folate in µg/L (or nmol/L). Red-cell folate is an alternative longer-term marker.
Folate (vitamin B9) is required for one-carbon transfers in DNA synthesis. Serum folate reflects recent intake; red-cell folate reflects longer-term status. UK reports use µg/L or nmol/L depending on the lab.
Why it matters
Low folate causes macrocytic anaemia and is important before conception (neural tube defect prevention). Diet, malabsorption, alcohol, and some medicines affect levels.
This guide is educational only and cannot diagnose you. Discuss results, especially anything outside your laboratory’s reference interval, or that does not match how you feel, with a GP or other appropriately qualified clinician.
How it affects the body
Folate donates one-carbon units for nucleotide synthesis: rapidly dividing cells (marrow, gut, early embryo) feel deficiency first.
Rapidly dividing cells: marrow, gut lining, early embryo: need folate. Deficiency yields megaloblastic anaemia and, peri-conception, raises neural tube defect risk.
For athletes
Athletes in weight-category sports with restricted diets should watch vegetable intake; women athletes planning pregnancy need explicit preconception folate advice from a clinician.
Weight-making and low-vegetable diets risk low folate. Women athletes who could become pregnant should follow UK preconception folic acid advice via a clinician or midwife: blood levels do not replace that guidance.
