If you are lactose-intolerant you figured out a long time ago that milk definitely doesn’t’ do your body good.
If you are vegan, you have already given up milk because it is an animal product and don’t believe that dairy does any body good.
I am willing to bet that after the question about how to get enough protein the next question you are asked is “How do you get enough calcium?’
A cup of whole milk as 276 mg of Calcium which is about 1/2 of the calcium your body needs everyday. Short of supplementation how in the world do you get enough protien?
Please inform yourself about the importance of calcium and how to make sure you get enough of it everyday. A great place to start is by reading this really great discussion by Dr. Campbell.