Specialty endocrinology ICD-9-CM 264-269 | ICD-10 E50-E56 MeSH D001361 | |
A vitamin deficiency can cause a disease or syndrome known as an avitaminosis or hypovitaminosis. This usually refers to a long-term deficiency of a vitamin. When caused by inadequate nutrition it can be classed as a primary deficiency, and when due to an underlying disorder such as malabsorption it can be classed as a secondary deficiency. An underlying disorder may be metabolic as in a defect converting tryptophan to niacin. It can also be the result of lifestyle choices including smoking and alcohol consumption.
Examples are vitamin A deficiency, folate deficiency, (scurvy), vitamin D deficiency, vitamin E deficiency, and vitamin K deficiency. In the medical literature, any of these may also be called by names on the pattern of hypovitaminosis or avitaminosis + [letter of vitamin], for example, hypovitaminosis A, hypovitaminosis C, hypovitaminosis D.
Conversely hypervitaminosis is the syndrome of symptoms caused by over-retention of fat-soluble vitamins in the body.