From the Guidelines
A serum B12 level of 233 pg/ml is considered borderline low, and according to the most recent guideline from 2022, it falls below the typical lower threshold of normal B12 levels, which range from 250-900 pg/ml 1.
Key Considerations
- Normal B12 levels are crucial for maintaining nerve function, DNA synthesis, and red blood cell formation.
- The ESPEN micronutrient guideline defines adequate status as blood/plasma concentrations within local reference ranges and the absence of clinical signs or symptoms related to micronutrients 1.
- A level of 233 pg/ml may not be considered deficient according to some standards, but it is close to the lower limit of normal, suggesting that supplementation might be beneficial, especially if symptoms are present.
Recommendations
- Discuss this result with your healthcare provider, especially if experiencing symptoms like fatigue, weakness, tingling in hands or feet, difficulty walking, memory problems, or mood changes.
- Consider B12 supplementation, typically starting with oral supplements such as cyanocobalamin 1000-2000 mcg daily, or B12 injections if absorption issues are present.
- Certain groups, including older adults, vegetarians/vegans, and those with digestive disorders, are at higher risk for B12 deficiency and may benefit from earlier intervention 1.
From the Research
Serum B12 Levels
- The normal range for serum B12 levels can vary depending on the laboratory and the specific test used 2.
- A study published in 2024 defined vitamin B12 deficiency as a serum vitamin B12 level below 250 pg/mL 2.
- Another study from 2020 used a cutoff of ≤ 200 pg/mL to define vitamin B12 deficiency in children 3.
- A serum B12 level of 233 pg/mL is close to the cutoff used in the 2024 study, but slightly below the normal range used in that study.
Comparison to Normal Ranges
- Based on the 2024 study, a serum B12 level of 233 pg/mL would be considered slightly below the normal range, but not definitively deficient 2.
- However, the 2020 study used a lower cutoff, and a level of 233 pg/mL would be considered within the normal range according to that study 3.
- It is essential to consider the specific laboratory and test used to determine the normal range for serum B12 levels.
Clinical Significance
- Vitamin B12 deficiency can lead to clinical and hematological abnormalities, including macrocytic anemia and neurological symptoms 2.
- Treatment with vitamin B12 supplementation can effectively reverse these abnormalities and improve both hematological and neurological outcomes 2, 3.
- It is crucial to consult with a healthcare professional to determine the clinical significance of a serum B12 level of 233 pg/mL and to discuss potential treatment options.