One half gallon of "fresh" milk. Milk is good for the bones because it offers a rich source of calcium, a mineral essential for healthy bones and teeth. Cow's milk is fortified with vitamin D, which also benefits bone health. Calcium and vitamin D help prevent osteoporosis.Other ways to improve bone health and reduce the risk of osteoporosis include regular physical activity and strength training, avoiding smoking and eating a healthy diet that is low in sodium and high in potassium. Most of the body's vitamin D is synthesized by the body on exposure to sunlight, so spending time outdoors is also important.