Egg is very good source of protine and viramin B12. You can incluid in your diet daily.
spinach is rich in iron and vitamin B12. Regular eating of spinach can increase your B12 Level.
Milk and dairy products like cheese, yogurt, paneer are very good source of vitamin B12 and protine.
Chicken Breast is also good source of vitamin B12.
Beef is rich in vitamin B12. If you add beef in your diet it will help you to increase your B12 level.
Soybean is very good option of protein. It is also rich in Vitamin B12.
Fortified cereal is rich in protein, vitamin B12 any many nutrition. You can take it in morning breakfast or light dinner.