Most of our body needs could be fulfilled with a proper vegetarian diet. There's no problem of consuming proteins, iron and mineral from alternative sources, as they can be found in dairy products and vegetables. The main problem that vegetarian athletes should be concerned about is lack of B2 Riboflavin and B12 vitamins. Those vitamins can't be found in dairy products. They can found in fortified whole grains, soybeans, dark green leafy vegetables and avocados.