I'm a type 1 diabetic, I take multi vitamins everyday. What other nutrients and/or supplements can I take to help prevent future issues with my body?

Several. Cinnamon and chromium can help with blood sugar control. Niacin (flush-free) and fish oil/flax seed can help with cholesterol management.
Several. I suppose i can give you several things you can take. However, here's the deal; regardless of what nutritional supplements you take, diet, exercise, an taking your meds keeps you a lot healthier than any supplement.