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rickets

(Encyclopedia)rickets or rachitis rəkīˈtĭs [key], bone disease caused by a deficiency of vitamin D or calcium. Essential in regulating calcium and phosphorus absorption by the body, vitamin D can be formed in t...

bowlegs

(Encyclopedia)bowlegs (genu varum), outward curvature of the leg bone (tibia) or thighbone (femur) causing the knees to separate when the feet are placed together. When the condition is severe enough to be consider...

cod-liver oil

(Encyclopedia)cod-liver oil, yellowish oil obtained from the liver of the codfish. The oil is rich in vitamin A and vitamin D (calciferol). It was long used as a preventive and cure for rickets in Baltic and Scandi...

Windaus, Adolf

(Encyclopedia)Windaus, Adolf äˈdôlf vĭnˈdous [key], 1876–1959, German chemist. He was professor of chemistry and director of the chemistry laboratories at the Univ. of Göttingen (1915–44). For his researc...

flat foot

(Encyclopedia)flat foot, condition of the human foot in which the entire sole rests on the ground when the person is standing. When the foot muscles are weakened or the ligaments are strained and stretched, the arc...

ultraviolet radiation

(Encyclopedia)ultraviolet radiation, invisible electromagnetic radiation between visible violet light and X rays; it ranges in wavelength from about 400 to 4 nanometers and in frequency from about 1015 to 1017 hert...

vitamin

(Encyclopedia)vitamin, group of organic substances that are required in the diet of humans and animals for normal growth, maintenance of life, and normal reproduction. Vitamins act as catalysts; very often either t...