Normal value vitamin b12
Pro Research Analysisby 
Searched over 200M research papers
Normal Vitamin B12 Values: An Overview
Introduction to Vitamin B12 Levels
Vitamin B12 is essential for the proper functioning of the central and peripheral nervous systems. However, defining normal levels of vitamin B12 can be complex due to variations in measurement methods and population differences.
Defining Normal and Deficient Vitamin B12 Levels
General Population Standards
In general, a vitamin B12 level of 200 pg/mL is considered indicative of deficiency, 200-299 pg/mL is borderline, and levels above 300 pg/mL are considered normal . However, there is no universal consensus on these cut-off points, and they can vary significantly across different studies and populations .
Variations by Population and Age
Research indicates that vitamin B12 levels can vary by age and population. For instance, in a study conducted in southwestern Colombia, the prevalence of B12 deficiency was found to be 17.8%, with higher rates in individuals over 60 years old and those with type 2 diabetes mellitus (T2DM) . Similarly, a study in Turkey found that normal reference levels for vitamin B12 ranged from 127-606 pg/mL for girls and 127-576 pg/mL for boys .
Measurement Methods and Their Impact
Different methods for measuring vitamin B12 can yield varying results. For example, radioisotopic assays tend to give higher results compared to microbiological methods like Euglena gracilis and Lactobacillus leichmannii assays . This variability underscores the importance of standardizing measurement techniques to ensure accurate diagnosis and treatment.
Special Considerations
Elderly Populations
Vitamin B12 levels tend to decrease with age. In a study of elderly individuals from urban low-income households, all participants had normal B12 levels, ranging from 226 to 1200 pg/mL, with a mean of 700 pg/mL . This suggests that while deficiency is a concern, it is not universal among the elderly.
Pregnancy
During pregnancy, vitamin B12 levels and related biomarkers can fluctuate significantly. A study suggested trimester-specific reference ranges for B12 biomarkers, noting that total serum B12 levels often fall below recommended cut-offs in the third trimester . This highlights the need for tailored reference ranges during pregnancy to ensure maternal and fetal health.
Conclusion
Normal vitamin B12 levels are generally considered to be above 300 pg/mL, but this can vary based on age, population, and measurement methods. Standardizing these cut-off points and considering specific population needs, such as those of the elderly and pregnant women, is crucial for accurate diagnosis and effective treatment.
Sources and full results
Most relevant research papers on this topic