Vitamina B12

http://www.forovegetariano.org/foro/showthread.php?13768-%BFCu%E1ntos-huevos-hay-que-tomar-a-la-semana-para-cubri-la-B12/page2&s=cf00e4fa11ebaa3e002a49d3e60a0e3e

http://www.forovegetariano.org/foro/showthread.php?10641-Ser%E9-ignorante-pero-Qu%E9-es-la-B12&p=122959#post122959

http://www.forovegetariano.org/foro/showthread.php?10418-Lo-que-todo-vegano-debe-saber-B12

http://www.haztevegetariano.com/p/505/Veganismo_y_Vitamina_B12