Answer by Steven Fowkes:

I like Mike Snapper‘s answer, except that I think the evidence for milk weakening bones is only based on homogenized cow’s milk. I hope somebody can correct me on that. The possibly unanswered question is whether or not raw of boiled milk does the same thing.
I think the mechanism of milk’s action to weaken bone integrity is more likely inflammatory than mineral driven. Although Mike is right that decalcification of bone is a serious pathology in modern times, I believe that demineralization of bone is a widespread phenomenon more linked to magnesium, vitamin D and K2 insufficiency than homogenized cow’s milk consumption. And let me expand that to say that fragile bones (osteoporosis and osteopenia) are just as linked to poor collagen quality as demineralization. There is a strong association of soft-tissue calcification with osteopenia, which point more towards calcium utilization than calcium deficiency.
There is an important distinction to be made between what “science” says and what “scientists” say. This goes to the question of bias and conflicts of interest on the part of individual scientists who may be employed by the cow’s milk industry or by governmental agencies promoting the only-calcium-is-needed-to-cure-osteoporosis myth. For decades, this myth has been operating in the medical community, and each dosage failure instigating an increase in the amount of calcium prescribed. I find it compelling that 1500-2500 mg of calcium-only supplementation is mostly ineffective while 200-400 mg of calcium combined with D3, A, K2 and magnesium–with or without additional strontium, boron, manganese, collagen, vitamin C, bioflavonoids, silicon, etc.–is effective. But, definitely, homogenized milk consumption is not only ineffective, but likely aggravates osteopenia risks.
I think there is reason to suspect homogenization as the milk-processing culprit that aggravates inflammation. Homogenization is the modern milk-processing process that has “changed” milk for the worse. Boiling milk has been a practice for centuries. Homogenization blends the normally compartmentalized lipid and aqueous fractions of milk, so that lipid-localized components of milk are made water-miscible, and vice versa. This makes for a high degree of consumer acceptance because the milk does not separate. But it potentially alters the way antigen presentation takes place in the walls of the gut.
There is another complicating factor regarding milk that may not be well delineated by scientific study: the fortification of reduced-fat milk with milk solids with high galactose levels.  All the non-fat and low-fat milk products have milk solids to make up for the lack of “mouth feel” from the milk fat. This is an independent aspect of milk inflammation that may not be separated out (controlled) in scientific studies of milk’s effects.
There may be additional factors to consider. I hope others may add to this.

What does science say about milk’s impact on human health?