Quite oddly, this is a hotly debated topic without an overabundance of scientific data on the matter. Certain studies have shown that milk could increase the risk of mortality and fractures in both men and women. Yet, other sources cite that excessive vitamin A (retinol) may be the cause of weaker bones in milk drinkers. Whatever the case, there are plenty of foods to help prevent osteoporosis besides dairy products, so do what is best for your own body-type and dietary preferences.