Vitamin B12 (Cobalamin) Blood Test

Vitamin B12 (Cobalamin) is a water-soluble vitamin that is derived from animal products such as red meat, dairy, and eggs. Vitamin B-12 is necessary for several bodily processes, including nerve function and the production of DNA and red blood cells. A vitamin B-12 level test checks the number of vitamin B-12 in the blood or urine to gauge the body's overall vitamin B-12 stores. This test is most often done when other blood tests suggest a condition called megaloblastic anemia. Pernicious anemia is a form of megaloblastic anemia caused by poor vitamin B12 absorption. This can occur when the stomach makes less of the substance the body needs to properly absorb vitamin B12.

🔍 What levels are considered optimal?

• Normal values are 160 to 950 pg/mL, or 118 to 701pmol/L.
• At the same time, patients with serum vitamin B12 levels between 150 and 400 ng/L are considered borderline and should be evaluated further by functional tests for vitamin B12 deficiency. Normal value ranges may vary slightly among different laboratories.

🔻 What does a vitamin B12 deficiency mean?

B12 blood level— if low, a deficiency is indicated, but it does not identify the cause. So, a low result of vitamin B-12 may suggest pernicious anemia or an overactive thyroid. Besides, vegans (people who don't eat any meat, dairy, or eggs) are most at risk for developing a B12 deficiency because, aside from fortified breakfast cereals, the only reliable dietary sources of vitamin B12 are animal-derived products. Not having enough B12 can lead to anemia, which means your body does not have enough red blood cells to effectively transport oxygen throughout your body. This can make you feel weak and tired. Moreover, vitamin B12 deficiency can cause damage to your nerves and can affect memory and thinking. People with low vitamin B-12 levels often experience neurological symptoms. It should be borne in mind that recovery from vitamin B12 deficiency takes time and you may not experience any improvement during the first few months of treatment. Improvement may be gradual and may continue for up to six to 12 months.

🔺 What does a high vitamin B12 level mean?

There is no consensus on the definition of high or elevated B12. Some studies have chosen >700 pmol/l as a high and 1500 pmol/l as a very high. If we talk about the reasons for the increased level, then the most common cause of high B12 in the blood is due to recent ingestion or injection of supplemental vitamin B12. If so, don't worry about overdosing on B12 supplements because excess can be excreted in your urine. It could also be possibly from your diet if high in animal products such as meat, eggs, and shellfish. Other causes of increased vitamin B12 levels include impaired liver function since B12 is metabolized through the liver, and therefore high B12 levels may serve as a proxy for poor liver function. Moreover, an abnormally high vitamin B-12 status can be an early sign of diabetes or certain types of leukemia. Elevated plasma vitamin B12 has been associated with an increased cancer risk (>813.2 pg/ml or 600 pmol/L). However, it is assumed that it is not vitamin b12 that causes cancer, but the destruction of liver cells in cancer leads to the release of the vitamin into the blood since it is stored in the liver.