View source for Vitamin B9 deficiency

==Background==
*Also known as [[folate]], folic acid
*Necessary for normal erythropoiesis, purine and thymidylate synthesis, amino acids metabolism, and histidine metabolism
*Found in most fruits and vegetables
*Recommended daily intake: 400 mcg or 500-600mcg if pregnant or lactating
*Total body stores of folate enough to supply requirements for 2–3 mo

===Causes===
*Most common cause of deficiency is inadequate dietary intake, usually secondary to:
**Chronic [[alcohol Abuse|alcohol abuse]]
**[[anorexia nervosa|Anorexia]]
**Inadequate or overcooked fruit/vegetable intake
*Other causes:
**Decreased absorption
***Tropical sprue
***Drugs ([[phenytoin]], sulfasalazine, [[trimethoprim-sulfamethoxazole]])
**Increased requirement
***Chronic [[hemolytic anemia]]
***[[Pregnancy]]
***Exfoliative skin disorders
**Folate loss due to [[hemodialysis]]
**Inhibition of reduction to active form (tetrahydrofolic acid) by [[methotrexate]]

==Clinical Features==
*Signs/symptoms of [[anemia]] which may be severe
*Glossitis
*Vague GI disturbances (e.g. anorexia, [[diarrhea]])
*'''No''' neurologic features (unlike B12 deficiency)

==Differential Diagnosis==
{{Anemia DDX}}

==Evaluation==
*CBC
**Macrocytic [[anemia]] (MCV>100 fL)
**RDW high
**Hypersegmented neutrophils
*Red blood cell folate level < 150 ng/mL

==Management==
*[[Folate]]: up to 1mg IV/IM or PO daily
**Maintenance: 0.4mg/day PO (non-pregnant/lactating) or 0.8mg/day PO (pregnant or lactating)

==Disposition==

==See Also==
*[[Folic acid]]
*[[Anemia]]
{{Template:Vitamin deficiencies DDX}}

==External Links==

==References==
<references/>

[[Category: FEN]]