Utility of measuring serum or red blood cell folate in the era of folate fortification of flour.
Folic acid is an essential nutrient involved in one-carbon metabolism. Insufficient folate can result in megaloblastic anemia and an increased risk of neural tube defects. In response to the latter, some governments have mandated the fortification of flour with folate. This had resulted in a documented rise in the serum and red blood cell folate levels in the population. This has impacted the potential utility of folate measurements to detect folate deficiency in the clinical context. Folate measurements, whether done in serum or red blood cells, are subject to analytical variation, especially the latter, which also affects the utility of such measurements. Examining the literature reveals that in clinical situations, generally <1% of the subjects will have folate deficiency regardless of potentially pre-disposing factors (e.g. anemia, anti-folate agents, inflammatory bowel disease). Data from our center for both pediatric and adult populations is presented that supports this observation. Consequently, there exists very few indications for folate determinations (unexplained macrocytosis, inborn errors of metabolism) and it may be more efficient to simply treat suspected cases.
Division of Medical Biochemistry, MUHC-Royal Victoria Hospital, 687 Pine Avenue West, Montreal, Quebec H3A 1A1, Canada. Electronic address: Brian.gilfix@mcgill.ca.
Brian M
BM
Gilfix
D004912:Erythrocytes / Q000378:metabolism; D005433:Flour; D005492:Folic Acid / Q000008:administration & dosage* / Q000097:blood*; D005494:Folic Acid Deficiency / Q000097:blood / Q000175:diagnosis; D006801:Humans
D005492:Folic Acid
Folate; Folic acid; Fortification; Red blood cells; Serum; Test utility