Hypervitaminosis
| 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 is a condition of abnormally high storage levels of vitamins, which can lead to toxic symptoms. Specific medical names of the different conditions are derived from the vitamin involved: an excess of vitamin A, for example, is called hypervitaminosis A.
Hypervitaminoses are primarily caused by fat-soluble vitamins (D, E, K and A), as these are stored by the body for longer period than the water-soluble vitamins.[1]
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.[2] The Dietary Reference Intake recommendations from the United States Department of Agriculture define a "tolerable upper intake level" for most vitamins.
Causes
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.[2]
Conditions include:
- Hypervitaminosis A
- Hypervitaminosis D
- Hypervitaminosis E
- Hypervitaminosis K, unique as the true upper limit is less clear as is its bioavailability.
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.
- Reliable information is lacking as to the vitamin K content of many foods or its bioavailability. With this in mind the Expert Committee established an AI rather than an RDA.
- This RDA (AI for men age 19 and older is 120 µg/day, AI for women is 90 µg/day) is adequate to preserve blood clotting, but the correct intake needed for optimum bone health is unknown. Toxicity has not been reported.
High-dosage A; high-dosage, slow-release vitamin B3; and very high-dosage vitamin B6 alone (i.e. without vitamin B complex) hypervitaminoses are sometimes associated with side effects that usually rapidly cease with supplement reduction or cessation.
High doses of mineral supplements can also lead to side effects and toxicity. Mineral-supplement poisoning does occur occasionally, most often due to excessive intake of iron-containing supplements.
Incidence
In the United States, overdose exposure to all formulations of "vitamins" was reported by 62,562 individuals in 2004 (nearly 80% [~78%, n=48,989] of these exposures were in children under the age of 6), leading to 53 "major" life-threatening outcomes and 3 deaths (2 from vitamins D and E; 1 from polyvitaminic type formula, with iron and no fluoride).[3] This may be compared to the 19,250 people who died of unintentional poisoning of all kinds in the U.S. in the same year (2004).[4] In 2010, 71,000 exposures to various vitamins and multivitamin-mineral formulations were reported to poison control centers, which resulted in 15 major reactions but no deaths.[5]
Before 1998, several deaths per year were associated with pharmaceutical iron-containing supplements, especially brightly colored, sugar-coated, high-potency iron supplements, and most deaths were children.[6] Unit packaging restrictions on supplements with more than 30 mg of iron have since reduced deaths to 0 or 1 per year.[6] These statistics compare with 59 confirmed deaths due to aspirin poisoning in 2003 [7] and 147 deaths known to be associated with acetaminophen-containing products in 2003.[7]
See also
References
- ↑ "Office of Dietary Supplements - Vitamin A". ods.od.nih.gov. Retrieved 2016-02-03.
- 1 2 Sizer, Frances Sienkiewicz; Ellie Whitney (2008). Nutrition: Concepts and Controversies (11 ed.). United States of America: Thomson Wadsworth. pp. 221, 235. ISBN 0-495-39065-8.
- ↑ Toxic Exposure Surveillance System (2004). "Annual Report" (pdf). American Association of Poison Control Centers.
- ↑ "National Center for Health Statistics".
- ↑ Bronstein, A. C.; Spyker, D. A.; Cantilena, L. R.; Green, J. L.; Rumack, B. H.; Dart, R. C. (2011). "2010 Annual Report of the American Association of Poison Control Centers' National Poison Data System (NPDS): 28th Annual Report". Clinical Toxicology. 49 (10): 910–941. PMID 22165864. doi:10.3109/15563650.2011.635149.
- 1 2 Tenenbein M (2005). "Unit-dose packaging of iron supplements and reduction of iron poisoning in young children". Arch Pediatr Adolesc Med. 159 (6): 557–60. PMID 15939855. doi:10.1001/archpedi.159.6.557.
- 1 2 Watson WA, Litovitz TL, Klein-Schwartz W, et al. (2004). "2003 annual report of the American Association of Poison Control Centers Toxic Exposure Surveillance System". Am J Emerg Med. 22 (5): 335–404. PMID 15490384. doi:10.1016/j.ajem.2004.06.001.