A study indicates that high doses of vitamin D alleviate sunburn. Taken one hour after the erythema, they reduce redness, swelling and inflammation of the skin. But the conclusions of the study encourage caution in the recommendations.
These results come from a double-blind, placebo-controlled clinical trial at Case Western Reserve University School of Medicine and Cleveland Medical Center. The results were published in the Journal of Investigative Dermatology, they highlight a new action of vitamin D: extremely fast anti-inflammatory activity!
Vitamin D: a rapid decrease in inflammation
In the study, 20 participants were randomized to receive either a placebo or 50,000, 100,000 or 200,000 IU of vitamin D one hour after being exposed to the forearm by a small UV lamp, so as to reproduce the appearance of a sunburn.
The researchers followed the participants 24, 48, 72 hours and 1 week after the experiment and collected skin biopsies. Verdict: Higher doses of vitamin D have longer-lasting benefits, including less skin inflammation 48 hours after the burn.
Activation of skin repair genes
Participants with the highest vitamin D blood levels also showed less skin redness. According to the researchers, vitamin D would therefore help to promote the protective barriers of the skin by rapidly reducing inflammation. But the last effect is more surprising: at a certain dose (very high, let’s remember), vitamin D would activate the genes linked to the repair of the skin barrier. But at doses inaccessible via food… or the sun
By measuring the activity of genes in the biopsies, the researchers also observed a potential mechanism behind its restorative action. Vitamin D would increase skin levels of an anti-inflammatory enzyme, arginase-1. The enzyme enhances tissue repair after damage and helps activate other anti-inflammatory proteins.
Scott JF et al., The Journal of Investigative Dermatology (2017). https://www.jidonline.org/article/S0022-202X(17)31558-0/pdf