What is the role of Homocysteine in cognitive function? I'm looking at this link : Homocysteine and cognitive impairments and **am looking for more information on specific cognitive impairments associated with elevated levels Homocysteine**. That article is not very clear on that point. I've seen some research papers about the study of this in elderly people and cardiovascular studies. I'm interested in average adults. I've been fascinated with the effect/lack of thereof of vitamin B6 on dreaming and Homocysteine is the first thing that I've stumbled upon in quite some time that is directly related to the B family of vitamins. **Has there been any research about what Homocysteine gets metabolized to if exposed to B-Complex vitamins versus Vitamin B6 alone?** Thank you for your input!

I'm not sure if this answers your question, but I'll give it a try anyway. Here's a diagram of homocysteine metabolism. Vitamin B12 is a cofactor for homocysteine methyltransferase, and folic acid is required for tetrahydrofolate (THF). As both vitamins are involved in homocysteine metabolism, the symptoms of folate and vitamin B12 deficiency are similar. Vitamin B12 deficiency can result in neurological symptoms due to abnormal myelin, but folate deficiency does not. Vitamin B12 also metabolizes methylmalonyl-CoA to succinyl-CoA as seem here, so the methylmalonic acid level is often measured to test for vitamin B12 deficiency.

Hyperhomocysteinemia is the condition of high levels of homocysteine, but it is usually due to low vitamin B12 or folate.