RBC Folate is useful for the evaluation of folate deficiency without significant fluctuations with diet. While serum folate concentrations may rise rapidly to a normal level after a balanced meal. RBC folate levels tend to increase more slowly. Furthermore, in iron deficiency, serum folate levels may be decreased whereas RBC Folate levels are not affected. RBC Folate concentrations may reduced in about 30% of patients with Vitamin B12 Deficiency.
*Note: Updated methodology and reference range effective August 1, 2017.