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 became even more unbalanced with Europe's successful appropriation of New World staple crops originally developed by Indians. The adoption of efficient, carbohydrate-rich American crops such as corn, potatoes, and cassava allowed Europeans and Africans to overcome chronic food shortages.