Definition. Rickets (in children) and osteomalacia (in adults) are two forms of a metabolic bone disease resulting from vitamin D deficiency. Both cause softening and weakening of bones because of defective or inadequate bone mineralization. Rickets. Copyright Â© Nucleus Medical Media, Inc.
The flow from west to east: Disease. In terms of diseases, the Columbian Exchange was a wildly unequal affair, and the Americas got the worst of it. The flow of disease from the Americas eastward into Eurasia and Africa was either trivial or consisted of a single important infection.
The Columbian Exchange. When Christopher Columbus and his crew arrived in the New World, two biologically distinct worlds were brought into contact. The animal, plant, and bacterial life of these two worlds began to mix in a process called the Columbian Exchange. The results of this exchange recast the biology of both regions and altered the history of the world.