Folate — Red Blood Cell Status
RBC folate is a longer-term measure of folate intake than serum folate. Folate is needed to make DNA, for methylation and to keep homocysteine low.
Red blood cell (RBC) folate is a longer-term measure of folate intake than serum folate, which is sensitive to recent meals. Folate is needed to make DNA, for methylation and to keep homocysteine low, and adequate status matters for women who could become pregnant.
The biomarker
- Name: Folate (RBC)
- Units: ng/mL
- Standard reference: above 140 ng/mL indicates adequate folate status, per NIH ODS (ranges vary by lab)
- Target for women of reproductive age: above 400 ng/mL — the level NIH ODS cites for the greatest reduction in neural tube defects
How to read your result
| Value | Interpretation |
|---|---|
| < 140 | Below the NIH ODS adequacy threshold — discuss with your clinician |
| ≥ 140 | Adequate folate status, per NIH ODS |
| > 400 (women of reproductive age) | The level NIH ODS cites for the greatest reduction in neural tube defects |
What moves the needle
- Diet. Dark green leafy vegetables, beans and peas, and oranges are good folate sources (NIH ODS).
- Testing. Ask whether to pair it with vitamin B12 and homocysteine — B12, B6 and folate are what break homocysteine down.
- Supplements. Do not start or change a folate supplement without a clinician.
Why this test is worth asking for
- RBC folate reflects longer-term intake, while serum folate moves with what you ate recently.
- Folate is needed to make DNA and for methylation, including keeping homocysteine at low levels.
- For women who could become pregnant, NIH ODS cites a specific RBC folate level linked to the greatest reduction in neural tube defects.
Related protocols
- Omega-3 Index — EPA + DHA Blood Test
- Homocysteine — B-Vitamin + Vascular Marker
- Zinc — Immune Mineral Status
Sources
- NIH ODS — Folate: Health Professional Fact Sheet
- NIH ODS — Folate: Fact Sheet for Consumers
- MedlinePlus — Homocysteine Test
AgeGen lab guides are educational only. We do not provide medical diagnosis, prescribe brands, or recommend specific doses. Talk to a licensed clinician before changing your supplement or medication routine.
