Vitamin poisoning
| Vitamin overdose | |
|---|---|
| Classification and external resources | |
| Specialty | endocrinology |
| ICD-10 | E67.0-E67.3 |
| ICD-9-CM | 278.2, 278.4 |
| Patient UK | Hypervitaminosis |
Hypervitaminosis refers to a condition of abnormally high storage levels of vitamins, which can lead to toxic symptoms. The medical names of the different conditions are derived from the vitamin involved: an excess of vitamin A, for example, is called hypervitaminosis A.
Hypervitaminosis primarily affects the fat soluble vitamins, as these are stored by the body for longer period than the water-soluble vitamins. However, avoiding excesses of both classes of vitamins can make the condition hard to get.
Generally, toxic levels of vitamins stem from high supplement intake and not from natural food. Toxicities of fat-soluble vitamins can also be caused by a large intake of highly fortified foods, but natural food rarely deliver dangerous levels of fat-soluble vitamins.Liver is a natural food which can cause toxic levels of vitamin A; vegetable sources of vitamin A will not cause toxic levels of vitamin A.
The Dietary Reference Intake recommendations from the United States Department of Agriculture define a "tolerable upper intake level" for most vitamins.
High dosage vitamin A; high dosage, slow release vitamin B3; and very high dosage vitamin B6 alone (i.e. without vitamin B complex) are sometimes associated with vitamin side effects that usually rapidly cease with supplement reduction or cessation.
With few exceptions, like some vitamins from B complex, hypervitaminosis usually occurs more with fat-soluble vitamins (D, E, K and A or 'DEKA'), which are stored in the liver and fatty tissues of the body. These vitamins build up and remain for a longer time in the body than water-soluble vitamins.
Conditions include:
According to Williams' Essentials of Diet and Nutrition Therapy it is difficult to set a DRI for vitamin K because part of the requirement can be met by intestinal bacterial synthesis.
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Wikipedia