vitamin B12 in serum/plasma
Reference interval
- Vitamin B-12: 210-920 pg/mL (< 100 pg/mL is diagnostic)
Principle
Clinical significance
Serum folate, serum Vitamin B-12 & red blood cell folate are among the most common tests ordered in the investigation of anemia. Since deficiency of either vitamin may be a cause of megaloblastic anemia, it is essential to determine the levels of both Vitamin B-12 & folic acid to establish the etiology of the anemia. Vitamin B-12 is an essential cofactor in intermediary metabolism & is required for the biosynthesis of DNA. Untreated vitamin B-12 deficiency may lead to severe anemia & potentially irreversible central nervous system degeneration. Folic acid is required in cellular metabolism & hematopoiesis, & prolonged folic acid deficiency may lead directly to megaloblastic anemia.
Decreases
* no evidence that vitamin B12 deficiency plays a role in Alzheimer's disease, dementia[3], or vascular pathology despite increase plasma homocysteine[4]
Specimen
More general terms
Additional terms
Component of
References
- ↑ Vitamin B12 Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0070150.jsp
- ↑ Mini Panel of 2 tests: Folate, Serum . Vitamin B12 Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0070160.jsp
- ↑ 3.0 3.1 Arendt JFH, Horvath-Puho E, Sorensen HT et al Plasma Vitamin B12 Levels, High-Dose Vitamin B12 Treatment, and Risk of Dementia. J Alzheimers Dis. 2021;79(4):1601-1612 PMID: https://www.ncbi.nlm.nih.gov/pubmed/33459639 PMCID: PMC7990402 Free PMC article
- ↑ 4.0 4.1 Geriatric Review Syllabus, 11th edition (GRS11) Harper GM, Lyons WL, Potter JF (eds) American Geriatrics Society, 2022