Atopic dermatitis, sometimes called eczema, is an inflammatory, recurring, non-contagious and very itchy skin disorder. It accounts for 20% of all dermatology visits. Patients with atopic dermatitis react to irritants, food, and allergens and their skin becomes red, flaky, itchy and easily infected. Atopic dermatitis has become increasingly common with sun avoidance and now affects almost 20% of children and 3% of adults in industrialized countries; its prevalence in the United States has tripled in the past thirty years. It is highly seasonal and usually improves after a summer holiday at the beach.
Dr Krishna Mutgi of the University of Toledo teamed up with Professor John Koo of the University of California at San Francisco to review all the evidence that vitamin D is involved in atopic dermatitis. I was especially impressed with Professor Koo, as he is heavily involved with Abbott Pharmaceuticals, who makes drugs for atopic dermatitis. That did not keep him from being senior author on this paper.
The paper reviewed all 58 articles on “vitamin D and atopic dermatitis,” finding 10 articles that researched causation, treatment and effect of vitamin D on the epidermal barrier, which is breached in atopic dermatitis. They found three studies that looked at vitamin D levels and severity of atopic dermatitis and all 3 studies found the higher your level, the less severe the atopic dermatitis.
They also found three small randomized controlled trials of oral vitamin D and atopic dermatitis with all three trials finding oral vitamin D helps. The same is true of UVB light and sunbeds, which seem to help even more. They also found that several papers confirmed that vitamin D is heavily involved in the breach of the epidermal barrier in atopic dermatitis.
After reviewing all the extant literature, the authors concluded:
“We believe that the increase in barrier maintenance proteins prevents the penetration of allergens and microbes, resulting in less activation of the inflammatory cascade. We further believe that the role of vitamin D in epidermal maintenance explains the greater prevalence of atopic dermatitis in (vitamin D) deficient patients, as well as the improvement observed after vitamin D supplementation.”
Much to my chagrin, the authors then only called for more studies and did not call for the diagnosis and treatment of vitamin D deficiency in patients with atopic dermatitis. They should have said that standard treatment should be enough vitamin D to obtain natural vitamin D levels (around 50 ng/ml), which usually requires 1000 IU/25 pound of body weight/day. If the atopic dermatitis is severe, I would double those recommendations, as I do in all severe “vitamin D deficiency diseases.” Also, don’t forget the sun or sunbeds, as vitamin D alone may not give you full relief.
Please notice that this paper added atopic dermatitis as yet another presenting sign and symptom of vitamin D deficiency, which is now the grand deceiver, a disease that can present in many guises and a myriad of ways, but whose core cause is low vitamin D levels.