Eczema: Does Vitamin B12 have any effects?

Affecting approximately 4% of the population, eczema is the second most common skin disease in France, following acne. This skin inflammation is characterised by redness, or erythema, accompanied by intense itching. Eczema patches can progress, depending on the severity of the condition. They may notably present blisters or thicken and dry out, thereby creating painful cracks. Eczema can be of genetic origin (atopic dermatitis), occur following a contact allergy or result from a simple irritation. Contrary to some misconceptions, eczema is not a contagious disease.

To alleviate the flare-ups of eczema, dermatologists often prescribe cortisone-based creams, a potent anti-inflammatory. In addition, it is possible to turn to cosmetic actives such as the vitamin B12. This fat-soluble molecule synthesised by certain bacteria indeed has interesting anti-inflammatory and antioxidant properties to counter eczema. The double bonds present in the chemical structure of vitamin B12 allow it to donate an electron to free radicals before they activate certain nuclear factors and lead to the release of pro-inflammatory cytokines, molecules involved in the pathogenesis of eczema.

Vitamin B12 can also directly influence the production of pro-inflammatory cytokines by the T lymphocytes of the immune system. By inhibiting this process, it limits the onset of redness and the characteristic itching of eczema. Studies in vitro have also shown that vitamin B12 can reduce the synthesis of nitric oxide (NO), a molecule that increases the dilation of blood vessels and is involved in various inflammatory processes. High levels of NO have indeed been found in eczematous lesions, evidence of the existing link between the molecule and the skin condition.

These various mechanisms of action have led several scientists to study the tangible effects of vitamin B12 on eczema during clinical trials, conducted with volunteers affected by this disease. These studies were carried out by comparing the SCORAD (Scoring Atopic Dermatitis) or the SASSAD (Six Area, Six Sign Atopic Dermatitis) before and after treatment. These are two clinical tools used to assess the severity of eczema, taking into account a wide range of criteria, such as the severity of lesions, the intensity of itching, and the impact of the disease on sleep, daily activities, and mood. The table below summarises the results obtained from 3 studies.