Gelatin is a protein that doesn't contain vitamins. Protein on its own does not contain vitamins. Luckily, the proteins in your diet aren’t isolated. The protein-containing foods you consume every day supply a variety of essential vitamins.Most sources of protein are good sources of all the B vitamins.Animal-based proteins are excellent sources of vitamin B-12, while legumes are rich in folate. You'll also get vitamins A and D from select protein foods.he protein-containing foods you consume every day supply a variety of essential vitamins. Most sources of protein are good sources of all the B vitamins. Animal-based proteins are excellent sources of vitamin B-12, while legumes are rich in folate.