The Photobiology of Vitamin D3 in Man

Abstract

As the industrial revolution swept across northern Europe in the 18th and 19th centuries, masses of people began to congregate in the cities. Coincident with the industrialization of northern Europe and North America and this mass migration was the rapidly increasing occurrence of a bone-deforming disease known as rickets. In 1550 this malady had been recognized and reported as a clinical entity that usually affected small children and was characterized by bowed, weak, and flabby legs, knuckle-like projections along the costochondral junctions of the rib cage (commonly referred to as the rachitic rosary), and deformities of the pelvis (1). For the next 250 years this disease plagued the children who lived in the industrialized cities of northern Europe and later in North America.