Drinking three to four glasses of milk would meet your calcium needs. For men, 1,000 milligrams between age 19 and 70 and 1,200 milligrams thereafter provides the calcium needed. If you're an adult, you don't need to drink any milk to keep your bones strong.  In some cases, drinking too much milk might be harmful.  Men with the higher intake had a 32 percent higher risk of developing prostate cancer.