According to the researchers, intakes of nutrients found in abundance in fruits and vegetables - namely, potassium, beta-carotene, vitamin C, and magnesium - were positively associated with bone health. Potassium appears to slow the excretion of calcium from the body while increasing rates of bone formation. Vitamin C appears to aid in bone formation, as well, while magnesium is extremely important in skeletal metabolism. In fact, recent studies suggest that magnesium deficiency may contribute to osteoporosis.
American Journal of Clinical Nutrition January 2000;71:142-151 (Free Full Text Article)
My favorite new response to people who ask me "Were am I going to get my calcium if I stop drinking milk and just eat vegetables?" will be to refer them to this article. Milk is not your friend. Humans are the only animals on this planet who drink another animal's milk-and we think this is normal?