To prevent iron deficiency, make sure your diet includes foods like red meat, fish, beans, egg yolks and nuts. The constant production of red blood cells also depends on nutrients like vitamin B12 or folic acid. Vitamin B12 can be found in foods such as liver, oysters, seafood or eggs; folic acid, in turn, exists in high levels in broccoli, asparagus, brussels sprouts and other green leafy vegetables. Vitamin C helps in the absorption of iron, making it more available whenever it binds to it. If vitamin C contributes to a greater absorption of iron, caffeine may have precisely the opposite effect. Therefore, avoid drinking coffee, tea and soft drinks. Alcoholic beverages or calcium (too much) can also be harmful to the body's absorption of iron.