What is B12?
Cobalamin, commonly called vitamin B12, is an essential cofactor. It is water-soluble, and the body needs it for many vital processes, but it cannot produce it by itself, so it must come from diet or supplements [1].
What Does B12 Do?
Vitamin B12 is crucial for the formation of red blood cells, nervous system health, protein and fat metabolism, DNA synthesis and brain function. All of this requires B12 [1].
B12 is a co-enzyme essential for cellular metabolism and necessary for DNA synthesis, in addition to its superoxide scavenging activity (ROS destroy plants and animals; B12 has anti-ROS properties). Lack of B12 is associated with various diseases, including megaloblastic anaemia, which is curable by supplementation of B12 [2].
In addition, B12 is essential for the proper function and structure of the cell, including DNA synthesis, methylation, and mitochondrial metabolism. It is vital to many physiological processes in the human body and prevents multiple health conditions, such as pernicious anaemia, neurological disorders, obesity, diabetes, dyslipidaemia, and foetal development complications [3, 4].
Benefits of Vitamin B12
An essential human nutrient, vitamin B12 is vital for a range of physiological processes in the body, including the formation and reproduction of red blood cells, the maintenance of the nervous system, DNA synthesis – and supplying energy to the body [5, 6].
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Vitamin B12 is also associated with improved cognitive function and other neurological parameters in the short term in the elderly and in the short-to-medium term in children. B12 also mediates antioxidant properties that can help to reduce oxidative stress [7, 8].
Low levels of B12 cause:
- Loss of appetite
- Lethargy
- Numbness or tingling in your hands and feet
- Mobility problems
- Confusion or memory loss
- Depression or irritability
- Loss of smell or taste
- Heart palpitations
- Pale skin
- Weakness
- Weight loss
- Glossitis – a painful, smooth, red tongue [6].
What’s more, vitamin B12 seems to possess anti-inflammatory properties. Higher serum concentrations are associated with lower blood levels of inflammatory markers, including interleukin (IL)-6 and C-reactive protein (CRP) [9].
What is the Optimal B12 Level?
The ‘optimal’ level of vitamin B12 depends on many factors - our age, diet and general health status determine the level that meets our needs. Still, multiple studies have aimed to establish those guidelines.
According to one study, the optimal range for plasma B12 for ages 0 – 1yr old – 180-1400 pmol/L, 1 – 11 yrs old – 260-1200 pmol/L, and 12 – 18yrs – 200-800 pmol/L. For 18yrs to 65yrs, and for older than 65 years – 200-600 pmol/L [10].
However, because these values arise from analyses measured by different instruments, it is essential to realise that these ranges may appear different. For example, for B12, the central 95th centile by Roche and Siemens analytical platforms was close to one another (181-678 ng/mL) [11].
Thus, regarding dietary intake, the following tolerable daily intake values are suggested: The average requirement of dietary vitamin B12 for the adult has been estimated at 0.5 micrograms/day, and an intake of 1. 0 micrograms/day would cover the requirements of practically all members of the population at a wide margin of safety [12].
But these are just guidelines. Please take individual needs into consideration. If you have a B12 deficiency, see a professional to determine your specific needs.
Does High B12 Mean Cancer?
It’s not clear whether and how high levels of vitamin B12 contribute to cancer. In several studies, levels of the vitamin have been linked with an elevated risk of certain cancers, but others show no such link.
One study showed that cancer patients often have elevated plasma levels of vitamin B12, but that link between high B12 levels and cancer did not apply to all forms of cancer. [13] Another study showed that a level of B12 > 1000 ng/L was associated with solid cancer, but the strength of the association did not increase with increasing levels of B12 [14].
Nonetheless, there is no evidence that high B12 levels cause cancer. Some studies have found no evidence of any biologically meaningful dose-response relationship between plasma B12 concentrations and cancer [13].
In sum, there is some evidence for a correlation between high B12 levels and cancers, but more research is needed. However, if you have high B12 levels, it’s probably a good idea to raise the issue with your health professional.