Milk can be so good to your body if taken in moderation. Milk has many biological products like insulin. Insulin enhances the growth and development of calves, which causes a biological response, and the result is the overproduction of sebum.
The sebum clogs pores leading to acne breakouts. However, since milk contains calcium and vitamin D that are needed by your body and bones but consider consuming it in moderation is the best you can do to reduce its negative impacts on your skin.
If you are milk intolerant, you should keep off and look for alternative calcium and vitamin D sources since milk consumption will lead to spontaneous breakouts.