NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.

We have included the web address to online sources used in developing and reviewing this article for documentation purposes only. Links included on this Sources page are valid, working links at the time they are posted. Please be aware that the source owner may, from time to time, reorganize the source web site, which can result in broken links on our pages. If you wish to access a source and come across a broken link, you may still be able to access it by entering just the parent web address in your browser's address bar (eg, "www.nih.gov") and then by entering the source title in the site's search feature.

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Clarke, W. and Dufour, D. R., Editors (2006). Contemporary Practice in Clinical Chemistry, AACC Press, Washington, DC. Pp 405-406.

Wu, A. (2006). Tietz Clinical Guide to Laboratory Tests, Fourth Edition. Saunders Elsevier, St. Louis, Missouri. 1124-1127, 410-413.

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Grund, S. (2007 August 27, Updated). Pernicious Anemia. MedlinePlus Medical Encyclopedia. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000569.htm through http://www.nlm.nih.gov/medlineplus/encyclopedia.html. Accessed on 1/30/08.

Van Voorhees, B. (2006 October 17, Updated). Folate Deficiency. MedlinePlus Medical Encyclopedia. Available online at http://www.nlm.nih.gov/medlineplus/ency/article/000354.htm through http://www.nlm.nih.gov/medlineplus/encyclopedia.html. Accessed on 1/30/08.

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