Veganism rests on:
there is a great deal of disagreement about moral issues, no one
disagrees with the notion that it’s wrong to inflict unnecessary
suffering or death on a human or an animal. We need a good reason to
inflict suffering or death on a human or animal. We might disagree about
whether necessity exists in any given situation and what constitutes a
good reason, but we would all agree that enjoyment or pleasure cannot
constitute necessity or serve as a good reason. This is part of our
conventional moral wisdom.
an example from the human context. If a person said that she believed
that it was morally wrong to inflict unnecessary suffering on children
but that beating children for pleasure was morally acceptable, we would
understandably be confused. If enjoyment can suffice as a good reason to
beat children, then there’s no bad reason to beat children. The
principle that it’s wrong to inflict unnecessary suffering on children
would be meaningless."
This is something that almost everyone agrees with.
If you believe in this, and want to live according to your beliefs, you will understand it is a moral obligation to go vegan: http://www.abolitionistapproach.com/what-michael-vick-taught-us/#.UfDiaW34V5s
is the position of the American Dietetic Association that appropriately
planned vegetarian diets, including total vegetarian or vegan diets,
are healthful, nutritionally adequate, and may provide health benefits
in the prevention and treatment of certain diseases. Well-planned
vegetarian diets are appropriate for individuals during all stages of
the life cycle, including pregnancy, lactation, infancy, childhood, and
adolescence, and for athletes.” — Academy of Nutrition and Dietetics
(formerly the American Dietetic Association)
who eat an adequate diet, and possible get their B-12 from e.g.
supplemented soy milk/grow their own vegetables in soil with B-12, eat a
diet that they thrive on and are healthy on.
A diet of a big amount of animal products is detrimental for human health: http://www.adelicatebalance.com.au/