BiomarkersRBC folate
Vitamins
RBC folate
Longer-term folate status, held in red blood cells
On your report it may say: Red blood cell folate
RBC folate measures folate stored inside red blood cells, which reflects the last 2–3 months rather than recent meals. It's the better test for planning pregnancy.
Typical ranges · ng/mL
nmol/L = ng/mL × 2.266
For women planning pregnancy, about 400 ng/mL (906 nmol/L) or more is the target linked to lower neural tube defect risk.
Ranges vary by lab, age and sex. The range printed on your report applies.
If it's low
Folate stores have been low for weeks to months.
Common causes
- Long-term low intake
- Alcohol
- Malabsorption
- Medicines that block folate
What you might notice
- Anaemia
- Tiredness
- Mouth sores
If it's high
High levels reflect good intake or supplements.
Common causes
- Supplements
- Fortified foods
What you might notice
- No symptoms
Testing
- Who should test
- Women planning pregnancy, and anyone whose serum folate result is unclear.
- How to prepare
- No fasting needed.
- When to retest
- After 3 months of a supplement.
What can help
Food sources
Talk to your doctor before conception if your level is below the pregnancy target.
Common questions
Why does it take months to change?
Red blood cells live about 120 days, so stores rise gradually.
Is it routinely tested?
Not often. Ask for it specifically if you're planning a pregnancy.
Explore further
Related markers
When to take them
Sources
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Build My Nutrition PlanFor general education only, not medical advice. Ranges shown are typical for adults; the range printed on your lab report applies. Talk to a qualified doctor about your results.