which are the sources of the B12?

Usually B12 deficiencies cause a problem when you're practicing a vegan diet, not simply a vegetarian diet, since eggs and dairy products are high in B12. As a vegetarian, you can eat those. It's simply the B12 found in meat that you're losing out on. There are supplaments you can take for B12, however, like spirulina and nori. However, they aren't known to be 'as' good as natural food sources. Some other natural sources of B12: yeast extracts, Vecon vegetable stock, veggieburger mixes, textured vegetable protein, soya milks, vegetable and sunflower margarines, and breakfast cereals