it carries plenty of b12 vitamins as well as protein, but as for the omega 3's we (veg heads) can get that from nuts, flax seed oil, green leafy vegetables, etc... So yes, short story long, it does actually work.
Oh, I also found out why fruits like watermelon, mango, and banana are banned. Too many carbs that are not balanced out by the fiber within them.
And in any case, not one thing is going to provide everything your body needs, goes without saying, but saying anyway. Unless of course, its Guinness Stout =)