High B12 and Folate

Vitamin B12 or B9 (commonly called folate) deficiency anemia occurs when a lack of vitamin B12 or folate causes the body to produce abnormally large red blood cells that cannot function properly.

Red blood cells carry oxygen around the body using a substance called hemoglobin.

Anemia is the general term for having either fewer red blood cells than normal or having an abnormally low amount of hemoglobin in each red blood cell.