Healthy memory function:
Vitamin B12 deficiency has been associated with memory loss, especially in older adults. The vitamin may play a role in preventing brain atrophy, which is the loss of neurons in the brain and often associated with memory loss or dementia. One study in people with early-stage dementia showed that a combination of vitamin B12 and omega-3 fatty acid supplements slowed mental decline. Another study found that even vitamin B12 levels on the low side of normal can contribute to poor memory performance. As a result, supplementing with this vitamin may improve memory, even in the absence of a clinically diagnosed deficiency. More research is needed to make sound conclusions on the effect of vitamin B12 supplements on memory and cognitive function.
High blood levels of the common amino acid homocysteine have been linked to an increased risk of heart disease. If you're significantly deficient in vitamin B12, your homocysteine levels become elevated. Studies have shown that vitamin B12 helps decrease homocysteine levels, which may reduce your risk of heart disease.