A 2018 study on the case of a 55-year-old man by experts at the Department of Neurosurgery, Ispat General Hospital, Rourkela, Odisha found the neurological link of vitamin B12 deficiency.

The patient’s “memory was disturbed, judgment impaired, had a changed personality as he had become isolated, apathetic, and withdrawn. He was also unwilling to think and depressed.”

The patient was treated with Vitamin B12 and folic acid.

“His blood was sent for vitB12 and folic acid estimation, and he was started with vitB12 1000 microgram intramuscularly once daily and olanzapine 5 mg at bedtime. His serum VitB12 and folic acid value came to be 90 pg and 10 ng/ml, respectively. His weakness improved significantly with immediate effect, all other symptoms took around 1 month to improve,” the study report says.