Vitamins are organic compounds essential for normal health. They are not synthesized in the body and must be supplied with the diet. Some vitamins form coenzymes, and others function as hormones. Their deficiency produces specific pathological conditions (avitaminosis).
According to National Health and Nutrition Examination Survey (NHANES) data, the most common vitamin deficiencies from 2003-2006 in the general United States population were vitamin B6, vitamin D, vitamin C, and vitamin B12.
Avitaminosis is any disease caused by chronic or long-term vitamin deficiency or caused by a defect in metabolic conversion, such as tryptophan to niacin. Avitaminosis may be acute or chronic, due to lack of single or more vitamins. Acute deficiencies are due to inadequate intake of vitamins. They respond to treatment more quickly than chronic types because of the absence of pathological changes which are invariably present in chronic deficiencies.
The diseases in the Avitaminosis group are pellagra, beriberi, scurvy, rickets, and night blindness. Avitaminosis is often due to a lack of nutrition or unavailability of food with certain vitamins.
Avitaminoses include
*Vitamin A deficiency causes xerophthalmia or night blindness
*Thiamine deficiency causes beriberi
*Niacin deficiency causes pellagra
*Vitamin B12 deficiency leads to megaloblastic anemia
*Vitamin C deficiency leads to scurvy
*Vitamin D deficiency causes rickets
*Vitamin K deficiency causes bleeding
Avitaminosis