What are some health issues that can arise from being vegetarian?

Reduced disease risk: A large body of research shows that vegetarian diets are "associated with lower blood cholesterol levels, lower blood pressure, less obesity & consequently less heart disease, stroke, diabetes, cancer, and mortality."-quoting from www.Vegetarian-nutrition.Info/updates/vegetarian_diets_health_benefits.Php/ iron deficiency is more common & low vit d & B12 could occur, but supplements can compensate.