It's also great for forming strong teeth. Vitamin D even lends a hand to an important mineral - it helps your body absorb the amount of calcium it needs. Drinking milk is a great way to get your body the D it deserves. Other tasty treats that are excellent sources of vitamin D are pudding and malted milk. And while you can't eat it, the sun is another great source of vitamin D - just be careful not to get too much sun, and always wear your sunscreen.
Tuna fish is a great source of vitamin D, and so are eggs.
For specific medical advice, diagnoses, and treatment, consult your doctor.