| Primary Unique Role |
Neurological function (myelin sheath) |
Neural tube development (in fetus) |
| Primary Sources |
Animal products |
Leafy greens, legumes, fortified foods |
| Body Stores |
Large (Years) |
Small (Months) |
| Absorption |
Terminal Ileum (Requires Intrinsic Factor) |
Duodenum/Jejunum (No Intrinsic Factor) |
| Key Unique Causes |
Pernicious anemia, vegan diet, gastric surgery |
Poor diet, alcoholism, pregnancy needs |
| Neurologic Symptoms |
PRESENT (Paresthesias, gait issues, cognitive changes) |
ABSENT |
| Key Lab Marker |
Elevated Methylmalonic Acid (MMA) |
Normal Methylmalonic Acid (MMA) |
| Treatment Danger |
Folate alone masks anemia, allows neuro damage to progress |
Less critical interaction (though diagnosis is key) |