Hey I thought you may be interested in the American Dietetic Associations take on veganism and vegeterianism.

They are the largest group of health care professionals on the planet, and are responsible for giving impartial advice to other health care professionals. They have no invested interests in either diets.

http://www.eatright.org/About/Content.aspx?id=8357

download the pdf - its stated that:
• “Well planned vegetarian diets are appropriate for all individuals during all stages of the life cycle, including pregnancy, lactation, infancy, childhood, and adolescence, and for athletes.”

• “Vegetarian diets tend to be lower in saturated fat and cholesterol, and have higher levels of dietary fiber, magnesium and potassium, vitamins C and E, folate, carotenoids, flavonoids, and other phytochemicals.”

• “Vegetarian diets are often associated with a number of health advantages, including lower blood cholesterol levels, lower risk of heart disease (which account for 25% of all human deaths in the UK and US), lower blood pressure levels, and lower risk of hypertension and type 2 diabetes. Vegeterians have a lower BMI and lower overall cancer rates (which count for another 25% of human deaths in the UK and US)”

• “Vegetarians and vegans (including athletes) meet and exceed requirements for protein.”