What should we know about Vitamin B12?

Vitamin B12, or cobalamin, is one of the eight B vitamins. It exists in several forms: cyanocobalamin, hydroxocobalamin, adenosylcobalamin, and methylcobalamin, with the first two being its stable forms. It is the cyanocobalamin that is found in cosmetics. Vitamin B12 has a chemical structure similar to heme, the cofactor involved in the transport of oxygen by the blood. Instead of iron at the central atom, cobalamin has a cobalt atom, hence its name. This complex chemical structure is the origin of one of its cosmetic peculiarities: vitamin B12 gives skincare products a rosy tint.

This vitamin also fulfils several roles within the body: production of red blood cells, protection of the myelin sheath, the structure around nerves optimising their function, regulation of DNA and fatty acid synthesis... However, it is not synthesised in the human body, hence the need for a external intake through diet to avoid deficiencies and the risks that arise from them (anaemia, pigment disorders, nerve damage...). Vitamin B12 is almost exclusively found in animal-derived products. For vegetarians and those with insufficient intake, additional supplementation may be necessary.

The vitamin B12 used in cosmetics is most often produced by fermentation. This can be carried out via two alternative pathways: aerobic, in bacteria, or anaerobic, in archaea. More often than not, the aerobic pathway is preferred, due to cost and technical considerations. The bacterial strains commonly used to produce vitamin B12 are Bacillus megaterium, Pseudomonas denitrificans and Propionibacterium freudenreichii.

Given that cobalamin is composed of a cobalt atom, it is crucial to add it to the culture medium, along with a source of carbon, nitrogen, and growth factors. During the fermentation process, vitamin B12 is produced within the bacteria. Once the synthesis is completed, after approximately 48 to 72 hours, the bacteria are harvested and then lysed to recover the vitamin B12, meaning their membrane is destroyed.

In addition to its biological functions, the vitamin B12 is beneficial for the skin and hair. It is therefore found in various cosmetic products under its INCI name "Cyanocobalamin".

• Vitamin B12 is a good anti-inflammatory.

  Found in both cosmetic products and soothing dermatological ointments, vitamin B12 is primarily known for its calming action. Several studies conducted with patients suffering from eczema or psoriasis have indeed demonstrated its effectiveness. Vitamin B12 works by inhibiting the release of certain pro-inflammatory cytokines, molecules involved in painful responses. It also limits the synthesis of nitric oxide (NO), a vasodilator.

• Vitamin B12 possesses antioxidant properties.

  Thanks to the numerous double bonds present in its chemical structure, Vitamin B12 can stabilise free radicals by donating an electron to them. In doing so, it combats the harmful effects of oxidative stress and protects cellular organelles and DNA. Oxidative stress is indeed the cause of premature skin ageing and can also cause pigmentation disorders. Vitamin B12 thus has photoprotective potential and can help prevent skin sagging and wrinkles.

• Vitamin B12 could potentially aid in wound healing.

  Some studies in vitro suggest that the use of vitamin B12 could be beneficial in the process of skin regeneration. By stimulating the proliferation of fibroblasts, this molecule could enhance the production of collagen and elastin, proteins essential for tissue healing. Vitamin B12 could also promote angiogenesis, which corresponds to the formation of new blood vessels. It would be interesting if studies in vivo could confirm these results and the healing potential of vitamin B12.

• Vitamin B12 could help to limit hair loss.

  The vitamin B12 could also be beneficial for hair and scalp, potentially helping to reduce hair loss. This natural phenomenon, while common, can be distressing, especially for those seeking to grow long hair. Studies on human follicles have shown that vitamin B12 could stimulate the signalling pathway of ß-catenin, a molecule that facilitates the transition between the hair loss phase and the growth phase. However, these initial findings still need to be confirmed through clinical trials before we can definitively say that the vitamin B12 has an effect on hair loss.

Sometimes used on skin prone to atopic or psoriatic tendencies and suitable for pregnant women, the vitamin B12 is a safe and gentle active ingredient for the skin. However, as always in cosmetics, there is no such thing as zero risk and a few marginal and benign cases of skin irritation following the use of vitamin B12 have been reported. These reactions can be explained by the sensitivity to cobalt that some people have. Indeed, cobalt can be allergenic and its contact can cause redness and itching. Therefore, if you have an allergy to cobalt, it is preferable to avoid cosmetics containing vitamin B12.

Good Practice : Before using a new product, we advise you to test it in the crook of your elbow or on your wrist.

Note : Only the precautions related to the topical use of vitamin B12 are mentioned here, not its oral intake.

The soothing and restorative properties of Vitamin B12 can be found in our after-sun serum. Designed for skin weakened by exposure to UV rays, this treatment combats dehydration and helps to replenish the hydrolipidic film. It contains 97% naturally derived ingredients and has a thermoregulatory texture that provides an immediate soothing effect on the skin. In addition to Vitamin B12, this serum contains panthenol, which is calming and hydrating, and carob pulp extract, rich in inositol, which promotes the development of a more intense and long-lasting tan.

• DAVLUY S. & al. A Review of Vitamin B12 in Dermatology. American Journal of Clinical Dermatology (2015).

• ZHANG D. & al. Microbial production of vitamin B12: a review and future perspectives. Microbial Cell Factories (2017).

• BAUMGARTNER M. & co. Vitamin B12, Folate, and the Methionine Remethylation Cycle—Biochemistry, Pathways, and Regulation. Journal of Inherited Metabolic Disease (2018).

• VAN DEN HEUVEL E. & al. Vitamin B12 in Relation to Oxidative Stress: A Systematic Review. Nutrients (2019).

• SHEKARCHI B. & al. Vitamin B12-loaded polycaprolactone/gelatin nanofibrous scaffold as potential wound care material. Biomedical Engineering Letters (2020).