A healthy diet is good for your mouth, too. Calcium and phosphorous can make your teeth stronger. You can get calcium from low-fat or fat-free milk, yogurt, and cheese; soy drinks and tofu; canned salmon; almonds; and dark green, leafy vegetables. Phosphorus comes from eggs, fish, lean meat, and dairy products. Vitamin C, which helps your gums, is in citrus fruit, tomatoes, peppers, broccoli, potatoes, and spinach.