http://chamworld.blogspot.com/2008/01/health-section-b-metabolic-bone.html
"MBD is a degenerative disease caused by poor ratio of Calcium and Phosphorus in the chameleon’s body. The chameleon’s bone structure is destroyed progressively, until the bone no longer able to support the chameleon’s body. Many numbers of causes can lead to MBD. But, the most common thing comes from poor nutrition, poor or lack of supplementing, and the absence of UVB light in the husbandry. ..."
"MBD is a degenerative disease caused by poor ratio of Calcium and Phosphorus in the chameleon’s body"...too bad that's only part of the story (sorry Sandra)...this explains it better IMHO...according to what I have read Ed Kowalski has been studying/keeping reptiles and amphibians for more than 30 years. He was a keeper at the Philadelphia Zoo’s Department of Herpetology...don't know if he still is or not... http://www.tracyhicks.com/MBD.htm