Eating an overall healthy diet is important to help him reach his height potential. In fact, malnutrition is the single most common cause of growth problems worldwide. In the United States, highly restrictive fad diets, eating disorders and participation in sports with strict weight requirements may cause some teens to not eat as well as they should, which could result in stunted growth.
If your teen eats a strictly vegan diet, the doctor may recommend adding B12-fortified breakfast cereals, soymilk or other foods to his diet, or that he take supplements. Vitamin B12 is found naturally only in foods that come from animals, such as red meat, poultry, fish, eggs and dairy products. If you are concerned that your teen is not growing normally or not eating a healthy diet, talk to your teen's doctor.