RBC Folate – Normal, High, Low

Folate is a naturally occurring B-vitamin that plays a role in DNA creation, repair and function as well as red blood cell production. Folate is found primarily in green leafy vegetables. A synthetic version known as folic acid can also be found in fortified foods.

The reference range of folate is:


Children   5-21 ng/ml

Adults  3-13 ng/ml


Children >160 ng/ml

Adults  140-628 ng/ml


A low value of folate can be associated with:

  • dietary deficiency of folate or B12, which is rare in the U.S.
  • malabsorption in the small intestine
  • heavy drinking
  • use of some drugs such as metformin, omeprazole, methotrexate or anti-seizure medications such as phenytoin
  • pregnancy
  • smoking

High levels of folate are normally okay as long as your vitamin B12 level is also normal. Cells need vitamin B12 to use folic acid and when vitamin B12 levels are too low, folic acid cannot be used and builds up in the blood.

Concerns on high RBC folate

People with higher levels of folate in their red blood cells were more likely to have two tumor-suppressing genes shut down by methylation, a chemical off switch for genes, researchers report in the December issue of Cancer Prevention Research.

RBC folate levels closely reflect long-term folate intake. Researchers said higher level of RBC folate leads to DNA methylation, which is equivalent to 10 years of extra aging, and the DNA methylation shut down the tumor-suppressing genes ERα and SFRP1 that are related to breast, prostate and lung tumors.

In a word, researchers said high RBC folate elevates risks of tumor, the effect is equivalent to 10 years of extra aging.





Leave a Reply