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 explains why Indian nations collapsed and European colonies thrived after Columbus's arrival in the New World in 1492. The Columbian Exchange explains why European nations quickly became the wealthiest and most powerful in the world. The Columbian Exchange explains why Africans were sold into slavery on the far side of the ocean to toil in fields of tobacco, sugar, and cotton. The Columbian Exchange even explains why pasta marinara has tomato sauce.