RBC Folate
RBC folate reflects longer-term folate status because folate is incorporated into red cells during their formation. Across US males aged 30 to 39, the median RBC folate in NHANES 2017-March 2020 is 481 ng/mL.
Unit: ng/mL · 12 slices · age and sex · 1 source
Filed under panels: Vitamins · topics: Nutrition
Red blood cell folate is the standard long-term folate status marker, reflecting the preceding 2-3 months of folate intake (the lifespan of a red blood cell). RBC folate is less affected by short-term intake variation than serum folate. NHANES measures RBC folate in the same file as the pre-pandemic folate subsample (P_FOLATE) and reports it in both ng/mL (LBDRFO) and nmol/L (LBDRFOSI).
Population Distribution
Browse by Demographic
| Age (years) | male (ng/mL) | female (ng/mL) |
|---|---|---|
| 20-29 | 259–613 (413) | 247–748 (421) |
| 30-39 | 260–719 (481) | 259–853 (465) |
| 40-49 | 272–833 (462) | 255–940 (477) |
| 50-59 | 256–1028 (509) | 280–892 (504) |
| 60-69 | 292–1140 (556) | 291–1129 (521) |
| 70+ | 288–1166 (605) | 307–1301 (640) |
Frequently Asked Questions
Why is RBC folate considered the long-term marker?
Folate is incorporated into red blood cells during erythropoiesis and remains there for the cell's lifespan (about 120 days). RBC folate therefore averages folate availability over the preceding 2-3 months, smoothing out daily fluctuations in serum folate.
Why does RBC folate use a different sample weight than other vitamins?
Folate analytes were measured on a one-half subsample of the NHANES 2017-March 2020 pre-pandemic cohort, so they require the special pre-pandemic folate weight WTFOLPRP rather than the full MEC weight. This is unique to the folate analytes on this site.
Why are these population percentiles, not clinical reference intervals?
LabNorms shows where a given measurement sits in the US adult population distribution. Clinical reference intervals describe a different question and are produced by laboratories using their own measurement protocols. Both can be useful but are not interchangeable.