My son is 17 years old and has been vegan for the better part of a year. He recently has stepped up his physical activity (biking, karate). I'm concerned about his diet and wondered if anyone has any resources they can share for teens. He had a scary experience swimming and lost his energy and I'm sure it's because of his diet. Also, if you can recommend a primary care physician who promotes a vegan lifestyle, that would be helpful. Thank you everyone.