There’s no miracle cure or substance that you can take to prevent osteoporosis. However, getting enough calcium through a healthy and balanced diet is a must. While milk does contain calcium, you’d need to consume at least 28 ounces of milk per day to get the recommended dose of 1000 mg per day.
That’s quite a lot of milk per day (which also needs to be absorbed), and if you’re also lactose-intolerant, just like many people, you can’t rely on milk to provide you with the necessary calcium so you might want to get it from other food sources or dietary supplements.