Question

Bob is a 63-year-old man who has been suffering from dementia. He has been a long-term vegan, and recently began having mood swings and depression. On testing his blood work, there is evidence of anemia and low vitamin B12. His serum homocysteine level was 65.34 μmol/L (normal range, 4.60–12.44). His doctor initiated weekly injectable vitamin B12 and 5 mg of folic acid daily. He has had a remarkable improvement in mood and his mental state has also improved. Without diet change, his serum homocysteine level was normalized to 8.32 μmol/L (normal range, 4.60–12.44).

Based on the symptoms presented, and response to treatment, which enzymes/vitamins appear to be deficient or not functioning properly? Why was the treatment successful?

Answer 1

Vit B12 deficiency may cause cognitive deficits and even dementia. This condition also known as pernicious anemia which causes decrease in red blood cells. Due to dietary deficiencies of vit B6, vit B12 and folic acid, metabolism of cysteine of methionine to cysteine is impaired and results in increase of homocysteine levels. For the convertion of methionine to homocysteine MTFR enzyme is needed and convertion of homocysteine to cysteine CBS enzyme is needed.