Vitamin B12 Deficiency

Vitamin B12 (cobalamin) deficiency occurs when the body lacks enough of this essential water-soluble vitamin, crucial for red blood cell formation, DNA synthesis, and nervous system health. Without adequate B12, the body produces abnormally large red blood cells that cannot function properly, leading to megaloblastic anemia.

Common symptoms include extreme tiredness, pins and needles, muscle weakness, sore red tongue, mouth ulcers, vision problems, and psychological issues ranging from depression to dementia. Neurological symptoms like paresthesia in hands and feet, cognitive disturbances, and memory problems are particularly concerning as they may become irreversible if untreated.

Main causes include pernicious anemia (autoimmune disorder preventing B12 absorption), vegan diets without supplementation, digestive disorders (Crohn's, celiac), aging (reduced stomach acid), certain medications (metformin, proton pump inhibitors), and stomach surgeries. The liver stores B12 for 3-5 years, so deficiency develops slowly.

Diagnosis relies on symptoms and blood tests. Treatment involves B12 injections initially, followed by oral tablets or regular injections depending on the cause. Vegans may need lifelong supplementation. Fortified cereals, nutritional yeast, dairy, eggs, meat, and fish are good B12 sources. Early treatment prevents permanent nerve damage and heart complications.