Lever
Lifestyle
- Regular medical check-ups
- Avoid excessive alcohol consumption
Blutwerte · Marker
Vitamin B12
Cobalamin · Cyanocobalamin · Methylcobalamin · B12
Vitamine & Nährstoffe
- Einheit:
- pmol/L
- Abbreviation
- B12
Vitamin B12 test quantifies the level of cobalamin in the blood, reflecting its availability for cellular processes.
Reference Ranges
Reference
148–740pmol/L
148
300
600
740
LowNormalHigh
Reference
Optimal
Unit · pmol/LRanges may vary slightly by laboratory; no significant sex-specific differences.
Overview
Übersicht
Vitamin B12, also known as cobalamin, is a water-soluble vitamin essential for DNA synthesis, red blood cell formation, and neurological function. It plays a critical role as a cofactor in two enzymatic reactions: the cytosolic methionine synthase reaction and the mitochondrial methylmalonyl CoA mutase reaction. These processes are vital for maintaining healthy nerve cells and producing genetic material in cells. Clinically, vitamin B12 is crucial for diagnosing and managing conditions like megaloblastic anemia, which results from impaired DNA synthesis in red blood cells, and various neurological disorders due to its role in myelin synthesis and repair. Deficiency in B12 can lead to severe neurological and hematological consequences, including cognitive impairment and psychosis. In the context of athletic performance and biohacking, vitamin B12 is often considered for its potential to enhance energy metabolism and cognitive function, although its direct impact on athletic performance is less clear. Biohackers may focus on optimizing B12 levels to support overall health and longevity, given its role in cellular energy production and neurological health. However, researchers have observed that B12 levels can be influenced by factors such as dietary intake, absorption efficiency, and genetic predispositions. Testing for B12 typically does not require fasting, but levels can be affected by recent supplementation or certain medications. It is important to consider these factors when interpreting B12 test results to avoid misdiagnosis or inappropriate treatment.
Klinische Bedeutung
Reduced vitamin B12 levels can indicate deficiencies leading to megaloblastic anemia and neurological disorders. Elevated levels are less common but may occur in certain liver diseases or supplementation.
Dynamics
Trend Interpretation
Rising Values
Progressively rising B12 levels may suggest excessive supplementation or liver dysfunction. Retest if levels exceed 740 pmol/L.
Falling Values
Progressively falling B12 levels could indicate malabsorption or dietary insufficiency.
Re-test Interval
4 weeks if outside optimal range
Etiology
Causes — High & Low
Cause
Elevated Levels
- Liver disease
- Supplementation
- Leukemia
- Polycythemia vera
- Renal failure
Cause
Low Levels
- Malabsorption syndromes
- Pernicious anemia
- Vegan diet
- Gastrointestinal surgery
- Chronic alcoholism
Protocol
How to Optimize
Lever
Nutrition
- Consume fortified cereals
- Include dairy products
- Eat eggs
Lever
Supplementation
- Cyanocobalamin
- Methylcobalamin
Note:
Consult a healthcare provider before starting supplements, especially if you have underlying health conditions.
Testing Guidelines
✓Fasting Not Required
✓Not Time-Sensitive
Testing Frequency
Annually for adults at risk of deficiency, more frequently if symptomatic.
Interfering Factors
- Recent B12 injections
- Certain medications
- Pregnancy
Related Peptides & Hormones
Homocysteine
hormone or peptideCorrelated with
Open Research Questions
Current research suggests that the relationship between vitamin B12 levels and Autism Spectrum Disorder (ASD) remains inconclusive, with inconsistent findings across studies regarding optimal reference ranges and confounding factors like dietary intake and genetic predispositions. Emerging research directions include exploring the role of B12 in gut microbiota balance and its impact on neurodevelopment. However, clinical questions remain unanswered regarding the long-term effects of B12 supplementation on cognitive and behavioral outcomes in children at risk for ASD.
35 Research Publications
862
Total Citations
8
Human/RCT
3.3
Avg. Influence
2025
Latest
Sort
Filter
01Top
#01
How I treat anemia in pregnancy: iron, cobalamin, and folate.
ReviewInfluence7.0
186
Researchers examined the prevalence and management of anemia in pregnancy, identifying vitamin B12 deficiency as a rising concern. The study discusses the implications of low maternal B12 levels on fetal development and the importance of addressing this deficiency.
02Top
#02
Vitamin B12 status in health and disease: a critical review. Diagnosis of deficiency and insufficiency - clinical and laboratory pitfalls.
ReviewInfluence5.0
153
This review focused on the complexities of diagnosing vitamin B12 deficiency, noting that it can present as various illnesses. Researchers found that current diagnostic tests have limitations, which can lead to misdiagnosis and inappropriate treatment.
03Top
#03
Severe megaloblastic anemia: Vitamin deficiency and other causes.
ReviewInfluence6.0
105
This study examined the causes of megaloblastic anemia, highlighting vitamin B12 and folate deficiencies as the most common contributors. Researchers found that effective diagnosis relies on specific laboratory findings, and treatment typically involves addressing the underlying deficiency.
04
#04
Laboratory assessment of vitamin B12 status.
HumanInfluence9.0
93
Researchers reviewed laboratory assessments for vitamin B12 status, highlighting the limitations of serum B12 tests. They found that a combination of different biomarkers may provide a more accurate assessment of B12 deficiency.
05
#05
Laboratory testing for cobalamin deficiency in megaloblastic anemia.
ReviewInfluence2.0
71
This study focused on laboratory testing for cobalamin deficiency in megaloblastic anemia. Researchers found that traditional serum cobalamin tests may not accurately reflect vitamin B12 status, suggesting the need for alternative biomarkers to improve diagnostic accuracy.
06
#06
Omeprazole and vitamin B12 deficiency.
ReviewInfluence1.0
45
This study examined the impact of omeprazole on vitamin B12 absorption, finding that it may hinder the release of B12 from dietary proteins. Researchers noted that while there is a concern about potential deficiency, the clinical significance remains unclear, warranting further research into dietary factors that may enhance absorption.
07
#07
Vitamin B12 deficiency.
HumanInfluence1.0
40
This study explored the complexities of vitamin B12 deficiency, noting its varied causes including malabsorption and dietary limitations. Researchers found that B12 deficiency can lead to significant health issues, particularly affecting blood and nervous system function.
08
#08
Vitamin B12 deficiency and metabolism-mediated thrombotic microangiopathy (MM-TMA).
ReviewInfluence2.0
38
Researchers examined the relationship between vitamin B12 deficiency and thrombotic microangiopathy (TMA). They found that severe B12 deficiency can mimic TMA symptoms, highlighting the importance of prompt identification and treatment of B12 deficiency.
09
#09
[Vitamin B12 (cobalamin)].
ReviewInfluence2.0
29
This study reviewed the clinical significance of vitamin B12 deficiency, highlighting its association with megaloblastic anemia and neurological disorders. Researchers discussed the biochemical parameters used to diagnose both clinical and subclinical deficiency.
10
#10
The application and interpretation of laboratory biomarkers for the evaluation of vitamin B12 status.
Harrington Dominic J, et al. · Annals of clinical biochemistry · 2025
ReviewInfluence2.0
25
Researchers summarized the biomarkers used to assess vitamin B12 status, emphasizing the importance of accurate diagnosis to prevent serious health issues. They found that no single test is definitive, and a combination of biomarkers may improve diagnostic accuracy.
Key findings
- 01Researchers observed that different biomarkers can indicate vitamin B12 deficiency or sufficiency.
- 02The review identified the significance of accurate interpretation of test results for proper health assessments.
- 03Researchers noted that understanding these biomarkers is crucial for preventing potential health issues related to vitamin B12 status.
Clinical Trials (16)
16
Total Trials
1,632
Total Enrolled
Effects of Vitamin B12 and Natural Orange Extract, and Their Combination on Physical and Mental Performance
NCT07341789ENROLLING_BY_INVITATION
Sponsor
Francisco Javier Martínez Noguera
Enrollment
20
Started
2025
Primary outcome
Wingate test
Vitamin b12Supplementation During Endurance PerformanceFlavonoidsMental FatigueBiomarker Feedback
Mecobalamin Combined With Anti-VEGF Intravitreal Injection for Retinal Vein Occlusion Treatment
Sponsor
First Affiliated Hospital of Chongqing Medical University
Enrollment
120
Started
2025
Primary outcome
Anatomical indicators-central foveal thickness
Retinal Vein Occlusion (RVO)
A Study to See if a Combination of Vitamins That is Injected Into a Muscle is as Good and Safe as a Vitamin That is Taken by Mouth
Sponsor
Medice Arzneimittel Pütter GmbH & Co KG
Enrollment
46
Started
2025
Primary outcome
Vitamin B12
Vitamin B12 Deficiency
Needle-Free Subcutaneous Injector and Conventional Intramuscular Injection of Mecobalamin in Diabetes Peripheral Neuropathy
NCT06400888UNKNOWN
Sponsor
Peking University Third Hospital
Enrollment
30
Started
2024
Primary outcome
concentration of plasma vitamin B12
Diabetic Peripheral Neuropathy
Vitamin B12: a Biological Marker of Systemic Disease or Infection Flare-up in Patients Treated with Tocilizumab?
NCT06654154RECRUITING
Sponsor
University Hospital, Clermont-Ferrand
Enrollment
56
Started
2024
Primary outcome
Variationof serum level of vitamin B12 (pmol/L) between a clinical suspicion of relapse autoimmune or autoinflammatory desease (AI/ID) or infection and a remission state, in patients treated by tocilizumab.
Level of Serum Vitamin B12 Level (in Pmol/L) If Relapse of (AI/ID) Under TocilizumabLevel of Serum Vitamin B12 Level (in Pmol/L) If Infection Under Tocilizumab
Effect of Methylcobalamin and Cyanocobalamin Consumption on Vitamin B12 Nutritional Status
NCT05785585RECRUITING
Sponsor
Fundació Eurecat
Enrollment
54
Started
2023
Primary outcome
Levels of total vitamin B12 in blood.
Vitamin B12 Nutritional Deficiency
Vitamin B12 Dose Escalation Trial in Pregnancy
Sponsor
George Washington University
Enrollment
50
Started
2023
Primary outcome
Assessing the steady state pharmacokinetics of B12 upon oral administration in pregnant women.
Vitamin B 12 Deficiency
Vitamin B12 vs B3 for Nerve Regeneration and Functional Recovery After Pediatric Traumatic Brain Injury
Sponsor
KRL Hospital, Islamabad
Enrollment
300
Started
2021
Primary outcome
Change in Stair Climb Test (SCT) score
Traumatic Brain Injury
Effect of Daily Consumption of Vitamin B12 Fortified Yoghurt on Vitamin B12 Status in Older Adults
NCT05993962COMPLETED
Sponsor
University of British Columbia
Enrollment
80
Started
2019
Primary outcome
Serum total B12 concentration
Vitamin B 12 Deficiency
Vitamin B12 Supplementation to Improve B12 Status and Child Development
NCT03258385COMPLETED
Sponsor
International Centre for Diarrhoeal Disease Research, Bangladesh
Enrollment
155
Started
2017
Primary outcome
Change in concentrations of biomarkers of vitamin B12 in mother-child pairs
Early Pregnancy
Folate One-carbon Malnutrition as the Metabostemness Risk Factor of Malignancy Tumor Development of NSCLC Patients
NCT03504098UNKNOWN
Sponsor
National Taiwan University Hospital
Enrollment
300
Started
2017
Primary outcome
Assessment of one-carbon nutrient (folate, choline, betaine, Vitamine B12) intake of lung cancer patients
Lung Cancer, Nonsmall Cell
Parental One-carbon Folate and Choline Nutrition Modulates Risk of Off-spring Cancer Development: Human Cohort Study
NCT02266641COMPLETED
Sponsor
National Taiwan University Hospital
Enrollment
118
Started
2014
Primary outcome
Assessment of maternal one-carbon nutrient (folate, choline, betaine, Vitamine B12) intake at the first trimester visit of pregnancy
Off-spring Cancer Risk
Pemetrexed, Cisplatin, and Vitamin B12 in Treating Patients With Mesothelioma of the Chest That Cannot Be Removed by Surgery
Sponsor
Centre Oscar Lambret
Enrollment
60
Started
2007
Primary outcome
Individual dosage-adapted protocol
Malignant Mesothelioma
Vitamin B12 Status and Response to Vitamin B12 Supplementation in Patients With Parkinson's Disease
Sponsor
Emory University
Enrollment
57
Started
2006
Primary outcome
Vitamin B12 concentration
Parkinson's Disease
Effect of Homocysteine-lowering Therapy With Folic Acid, Vitamin B12, and Vitamin B6 on Endothelium-dependent Vasodilatation of Forearm Resistance Vessels in Patients With Coronary Heart Disease
Sponsor
Insel Gruppe AG, University Hospital Bern
Enrollment
36
Started
2005
Primary outcome
Flow mediated dilatation (FMD)
Cardiovascular DiseaseEndothelial Dysfunction
Holotranscobalamin Remains Unchanged During Pregnancy
NCT00467623COMPLETED
Sponsor
University of Aarhus
Enrollment
150
Started
1995
Vitamin B12 Deficiency
Publication Trend
Research publications about Vitamin B12 over time
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