While all B vitamins are important for brain health, B-12 is perhaps the most important. Unfortunately, it is also the most common B vitamin deficiency in western countries. B-12 deficiency has been linked to memory loss, cognitive decline, depression, decreased mobility, and fatigue.
B-12 is critical for the production of myelin sheaths, which surround nerve cells and are essential for efficient conduction of nerve signals .
In fact, B-12 is so important for the brain that its deficiency has been linked to measurable brain atrophy .
When choosing a B-12 supplement, opt for the methyl form which is more stable and readily used by the body than its synthetic counterparts.