Can't Avoid Sunburn? Vitamin D Might Help
Maybe you’ve been out on the water — on a fishing trip for example. And even though you did use sunscreen, by the time you get home, you can tell a nasty sunburn is in your future. Until now, all you could do is take palliative steps — cool baths, maybe an anti-inflammatory medication or a local anesthetic cream or spray to counter the worst of it. A new study just published in the Journal of Investigative Dermatology suggests that good old vitamin D might be able to help.
Dr. Jeffrey F. Scott from the Cleveland Medical Center and colleagues investigated the possibility that vitamin D might prevent the deleterious effects of sun exposure on the skin. To do so, they recruited 20 adults (over the age of 18) who submitted to receiving exposure to a UV lamp. The lamp provided light approximating that of sunlight. Initially, the researchers determined how much light was necessary for each person to react with skin reddening (the MED or minimal erythema dose).
The participants were randomly assigned to receive a placebo, 50,000 IU, 100,000 IU, or 200,000 IU vitamin D3 within one hour of receiving three times the MED of sunlight on their arm. For comparison, the Recommended Dietary Allowance of vitamin D is 600-800 IU per day, depending on age and physiological status.
In the usual course of events, the authors wrote, skin redness peaks early after UV light exposure, while skin thickness increases steadily for up to 2 weeks post exposure. With a three-fold MED dose, thickness increased 72 hours and one week after irradiation — statistically significant differences. In addition, they found that there was a significantly lower expression of tumor necrosis factor alpha (TNF-a) inducible nitric oxide synthase (iNOS) — two pro-inflammatory mediators.
The investigators also found that those individuals who didn’t respond to vitamin D supplementation by increased levels of serum vitamin D showed increased expression of several pro-inflammatory genes, not seen in the people whose serum levels increased.
While this was a small study, with only six people receiving the highest dose of vitamin D, it is a positive “proof of concept” investigation. Obviously, it needs careful replication before treatment with high-dose vitamin D can be recommended to prevent at least some of the deleterious effects of excess UV radiation exposure. Note that there is no evidence that supplementation with smaller amounts of vitamin D will be effective.
In the meantime, the best advice remains the use of ample amounts of sunscreen to prevent burns, and the recommended amounts of vitamin D to provide its known benefits for calcium absorption.
