A meta-analysis published in the journal Nutrients suggests that vitamin D supplementation may be a safe and effective treatment for atopic dermatitis.
Atopic dermatitis (AD), also known as eczema, is a very common chronic inflammatory disease characterized by red, dry and itchy skin. The cause of AD remains largely unknown; although researchers believe it likely results from a gene variation that affects the skin’s ability to act as a barrier and immune system dysfunction.
The current available treatment options focus on reducing skin inflammation and include antihistamines and corticosteroids. These traditional treatments elicit various side effects, and therefore, poor patient compliance. Thus, the discovery of an alternative treatment would be extremely valuable.
In 2012, a review concluded that vitamin D supplements may offer an effective treatment for AD. However, the review consisted of only two low quality studies.
In a recent review and meta-analysis, researchers evaluated double-blinded randomized controlled trials (the highest quality study design) to evaluate the efficacy of vitamin D supplementation for AD. In addition, they also assessed the vitamin D status of AD patients in comparison to healthy adults.
The researchers analyzed a total of seven studies to compare the vitamin D levels among AD patients and healthy adults, totaling 986 AD patients and 657 controls. Their analysis discovered that the AD group had significantly lower vitamin D levels than healthy adults with an average difference of 2.03 ng/ml (p < 0.0001).
The researchers also performed secondary analyses categorized by age. They found that children with AD had significantly lower vitamin D levels than children without AD (p = 0.0006). However, while adults with AD had lower average vitamin D levels than adults without, this difference was not statistically significant (p = 0.50). According to the researchers, this insignificant relationship most likely occurred due to a small sample size (134 AD patients vs. 128 controls).
Most importantly, the researchers reviewed four randomized controlled trials (RCTs). The RCTs used daily doses of 1000 IU to 1600 IU and lasted between one to two months. The meta-analysis revealed that the severity of AD significantly decreased after vitamin D supplementation as indicated by lower scores in both Scoring Atopic Dermatitis (SCORAD) index and Eczema Area and Severity Index (EASI) (p < 0.00001).
The researchers concluded,
“In comparison with a placebo group, vitamin D supplementation decreased AD severity and improved the symptoms and clinical signs of AD.”
Tovey, A. & Cannell, JJ. Vitamin D supplementation may provide relief for patients with atopic dermatitis. The Vitamin D Council Blog & Newsletter, 2016.