Causes of nervous system impairment with vitamin B12 malabsorption
What is known about the etiology of nervous system impairment associated with vitamin B12 malabsorption?
The deficiency of methionine synthetase activity secondary to absence of its cofactor (B12) leads to accumulation of homocysteine.
The resulting impairment in DNA synthesis is responsible for the megaloblastic anemia associated with vitamin B12 deficiency, while neurologic abnormalities are the result of failure to maintain methionine biosynthesis.
