What are the hair benefits of Vitamin B12?

Harmful to all cells in the human body, oxidative stress can also damage hair and weaken it. When the balance between the number of antioxidants and free radicals is no longer maintained, the latter can easily react with the molecules of the hair bulb and damage this structure, thereby exacerbating hair loss. Furthermore, oxidative stress can accelerate the greying of hair. Several mechanisms are at play, including the decrease in the activity of tyrosinase, the enzyme catalysing the oxidation of tyrosine into melanin.

To prevent damage caused by free radicals, it is beneficial to have a high intake of antioxidants. As for the vitamin B12, its anti-radical properties are relatively well documented and have been the subject of several studies in vitro. It has been particularly shown that the chemical structure of this molecule allows it to stabilise reactive oxygen species through an electron donation. Vitamin B12 also activates glutathione, a molecule that contributes to maintaining the redox potential of cells.

Note : The antioxidant effects of vitamin B12 have not been studied in vivo. Therefore, it has not been proven that the topical application of care products enriched with this vitamin can slow down hair whitening.

There are reasons to believe that vitamin B12 could combat hair loss. Indeed, studies conducted with human hair follicles have shown that the addition of vitamin B12 to the culture medium led to the elongation of the hair shaft. More specifically, adding 2.5 µg/mL and 25 µg/mL resulted in respective increases of 6.2 ± 2.1% and 15.4 ± 3.8% in shaft growth. The mechanism involved appears to be as follows: vitamin B12 could stimulate the translation of the ß-catenin messenger RNA. Now, ß-catenin is a signalling molecule that allows the transition between the telogen phase, corresponding to the time when hair falls out, and the anagen, or growth phase. By promoting the entry into the anagen phase, vitamin B12 could help to reduce hair loss.

Despite these promising results, it is necessary to conduct clinical trials before asserting that topical or oral application of Vitamin B12 can counteract hair loss.