veganism: I know its not in the proper section. I'm just putting it here so I can get biased-the-other-way answers, and see if I get anything good :)|||If it's not done sensibly, a massive protein deficiency. That's the big one.|||I am a semi-vegetarian, and what i miss is basically my favorite meats. Steak and Salami especially. semi-vegetarian diets consist largely of vegetarian foods, but may include fish and sometimes poultry, as well as dairy products and eggs.poorly planned vegan diets can be low in levels of calcium, iodine, vitamin B12 and vitamin D. being a vegan is tough, you have to check everything to see what is in different types of foods.just make sure your diet keeps you healthy and doesn't leave you feeling lifeless and lazy. The most common reasons for becoming a vegan are ethical commitment or moral conviction concerning animal rights or welfare, the environment, human health, and spiritual or religious concerns, but some just do it for a challenge. xD