I think that it's very important to know that Vitamin A intake is good for bone health, though overdosing can have an adverse effect;
"Some Vitamin A, like calcium, Vitamin D, magnesium and Vitamin K, is necessary for healthy bones, but regular overdosing on the amount of vitamin A consumption has been associated with adverse skeletal effects.
Vitamin A in large doses is believed to inhibit osteoblasts, which are the cells that actually form new bone by laying the matrix of bone down. Overdosing on Vitamin A can also interfere with vitamin D activity and thus could inhibit proper calcium absorption, and stimulate osteoblast bone cells, which wear bone away in the normal process of remodeling. The net effect is increased bone resorption for a net thinning of bone and an increased fracture risk...."
http://www.opposingviews.com/i/vitamin-a-essential-for-bone-health-but-b...
Source: www.opposingviews.com