Vitamin B12, serum
Vitamin B12, cobalamin, is part of the B complex family of vitamins. Vitamin B12 is necessary for converting the inactive form of folate to its active form, playing an important role in the production and function of red blood cells (RBCs) and breakdown down the blood toxin homocysteine.
A deficiency of B12, like folate, can cause anemia and elevated homocysteine. Decreased B12 levels can also decrease the cell’s ability to absorb folate, which can contribute to folate deficiency. Low B12 is associated with cognitive impairment and dementia, specifically, Alzheimer’s disease, vascular dementia, and Parkinson’s disease.
Alternate Name: B12, Cobalamin, Cyanocobalamin
- Vitamin B12 (Cobalamin)
Methodology: Immunoassay (IA)
Fasting: No.
Water: Drink plenty of water to stay well hydrated.
Medications: Take all medications as prescribed.
Special considerations: B vitamin supplements should be avoided 3 days prior to testing as they can interfere with results.
2-3 business days
Result turnaround times are estimates and not guaranteed. Due to factors outside of our control, such as weather, holidays, confirmation/repeat testing or equipment maintenance, our lab may require additional time to complete tests.
Vitamin B12 is necessary for converting the inactive form of folate to its active form, playing an important role in the production and function of red blood cells (RBCs) and breakdown down the blood toxin homocysteine.
A deficiency of B12, like folate, can cause anemia and elevated homocysteine. Decreased B12 levels can also decrease the cell’s ability to absorb folate, which can contribute to folate deficiency. Low B12 is associated with cognitive impairment and dementia, specifically, Alzheimer’s disease, vascular dementia, and Parkinson’s disease.
The absorption of B12 depends on a protein called intrinsic factor (IF). Without IF, vitamin B12 cannot be absorbed. The most common causes of B12 deficiency are a lack of intrinsic factor and low stomach acid, which is also required for vitamin B12’s absorption. In vegans and vegetarians, a lack of dietary intake of B12 is the most common cause of B12 deficiency.
The research shows that deficiencies in vitamin B12 and folate can lead to macrocytic anemia, hyperhomocysteinemia, and neurologic and psychiatric disorders.
Vitamin B12 (Mayo Clinic)
Cario H., Smith D.E., Blom H., et al. Dihydrofolate reductase deficiency due to a homozygous DHFR mutation causes megaloblastic anemia and cerebral folate deficiency leading to severe neurologic disease. Am. J. Hum. Genet. 2011;88:226–231.
Lachner C., Steinle N.I., Regenold W.T. The neuropsychiatry of vitamin B12 deficiency in elderly patients. J. Neuropsychiatry Clin. Neurosci. 2012;24:5–15.
Moore E., Mander A., Ames D., et al. Cognitive impairment and vitamin B12: a review. Int Psychogeriatr. 2012 Apr;24(4):541-56.
Oh, R. & Brown, D. L.. 2003. Vitamin B12 deficiency. American Family Physician 67: 979-86.
Owczarek D., Rodacki T., Domagala-Rodacka R., et al. Diet and nutritional factors in inflammatory bowel diseases. World J. Gastroenterol. 2016;22:895–905.