Exercise and reduced alcohol consumption are known ways to help keep the brain young, but research from the National Academy of Medicine shows that the multivitamin B12 is also effective in protecting an aging brain. Animal protein foods like meat, cheese and eggs are the only reliable natural dietary sources of B12, but getting an ample amount of the vitamin from those foods can be difficult for older people. With B12 supplements, you can get around that issue and protect against depression, psychosis and a loss of energy, all symptoms of a lack of B12. If you’re looking for added protection for your brain, perhaps you should consider taking this vitamin.