Folate Deficiency

About Folate Deficiency

Folate vitamin B9 deficiency is less common than B12 deficiency but has important implications. Folate is essential for DNA synthesis, red blood cell formation, and fetal neural tube development. Causes include inadequate intake processed diets lacking fresh vegetables, alcoholism, malabsorption celiac disease, inflammatory bowel disease, increased demand pregnancy, lactation, rapid growth, hemolytic anemia, dialysis, and certain medications methotrexate, trimethoprim, phenytoin, sulfasalazine. Symptoms are similar to B12 deficiency: fatigue, weakness, pallor megaloblastic anemia, glossitis, and gastrointestinal symptoms. Unlike B12 deficiency, folate deficiency does not cause neurological symptoms, which is an important differential point. However, folate deficiency can mask the hematological signs of B12 deficiency while allowing neurological damage to progress, so B12 status is checked before folate treatment begins. Folate is critical in early pregnancy for preventing neural tube defects spina bifida, anencephaly. The neural tube closes by day 28 of gestation, often before pregnancy is recognized. Public health bodies such as the CDC and NHS recommend folic acid supplements for people who could become pregnant or are trying to conceive, with higher doses prescribed for some at increased risk. Food fortification with folic acid, mandated in the US since 1998, has substantially reduced neural tube defects. Diagnosis involves serum folate below 3 ng mL, with RBC folate being a better long term marker. Elevated homocysteine with normal methylmalonic acid distinguishes folate from B12 deficiency. Treatment is folic acid replacement, with dose and duration set by a clinician. MTHFR gene variants, commonly tested but rarely clinically significant, do not change treatment recommendations.