You need to really do your research before you make a decision. I stopped eating meat when i was around 15, im now 33 and through a blood test found out im severely deficient in b12 (which is found in meat, eggs, and milk), so now i get weekly b12 shots from the doctor, i also found out i have a borderline-low thyroid…thing is i ate ALOT of soy over the years, there are alot of good tasting veggie burgers, hotdogs, etc. made with soy, and i was drinking soy milk every day, im not exactly sure if all the soy i ate contributed to my thyroid being low. I know alot of vegetarians take supplements (something i didn't do but should have)…so just do some research, or it's best you don't just stop eating meat all together, you have to slowly go off meat, start eating less each week and then finally stop after you have found how to replace meat for something that has the same nutrients. I know many people go veg for the health benefits, but if you don't do it the right way you can do some harm to your body, thyroid problems can cause an increase in your cholesterol.

If you eat eggs and dairy, you'll be OK.

If you have thyroid problems or if thyroid problems run in your family, do not eat soy at all. (This means you should reconsider vegetarianism as you'll have very limited food choices.)

There are vitamins you can take. You can also get protein from lots of recipes and shakes.

http://vegetarian.about.com/

http://vegetarian.about.com/od/healthnutrition/qt/highprotein.htm

Is it regular vegetarian, you can get it through milk and other products. Is it "vegan", then you have a problem.