vitamin deficiency disease

Although deficiency diseases have been described in laboratory animals and humans deprived of single vitamins, in human experience multiple deficiencies are usually present simultaneously. The eight B-complex vitamins function in coordination in numerous enzyme systems and metabolic pathways; thus, a deficiency of one may…

Avitaminosis (vitamin lack) may be encountered when there are increased losses of vitamins such as occur with chronic severe diarrhea or excessive sweating or when there are increased requirements for vitamins during periods of rapid growth, especially during childhood and pregnancy. Fever and the endocrine…

…diet with foods containing particular vitamins, deficiency diseases such as rickets (due to deficiency of vitamin D) and scurvy (due to lack of vitamin C, or ascorbic acid) practically disappeared from Western countries, while deficiency diseases such as beriberi (caused by lack of

…is characterized by vitamin B₁ deficiency, sometimes also occurs in patients affected by metastatic cancer, HIV/AIDS, or chronic nutrient malabsorption. The main psychological feature is irregularity in recent memory, sometimes so severe as to produce “moment-to-moment” consciousness; such people can store new information only for a few seconds and report…

Vitamin A deficiency primarily affects the retinas and skin, but components of the vitamin B group are essential for normal development and functioning of the nervous system. Wernicke-Korsakoff syndrome (common in alcoholics) results from a thiamine (vitamin B₁) deficiency and consists of eye…

…sources of vitamin D, a deficiency of the vitamin can occur when exposure to sunlight is limited. Lack of vitamin D in children causes rickets, a disease characterized by inadequate mineralization of bone, growth retardation, and skeletal deformities such as bowed legs. The adult form of rickets, known as osteomalacia,

Inadequate intake of a specific vitamin results in a characteristic deficiency disease (hypovitaminosis), the severity of which depends upon the degree of vitamin deprivation. Symptoms may be specific (e.g., functional night blindness of vitamin A deficiency) or nonspecific (e.g., loss of appetite, failure to…

Vitamin requirements are specific for each organism, and their deficiency may cause disease. Vitamin deficiencies in young animals usually result in growth failure, various symptoms whose nature depends on the vitamin, and eventual death.