PORTLAND – Short-term daily oral supplementation with 5000 IU of vitamin D3 was safe and significantly outperformed placebo for lessening the signs and symptoms of atopic dermatitis (AD), according to the results of a randomized, double-blind trial of 65 patients with moderate to severe disease.
At week 12, average improvements on the Scoring Atopic Dermatitis (SCORAD) index (standard deviation, 11.1 points) were 21.2 points in the vitamin D3 group and 13.9 points (standard deviation, 12.3 points) in the placebo group (P = .02), Karen Sanchez-Armendariz, MD, reported at the annual meeting of the Society for Investigative Dermatology. “Vitamin D3 should be considered a valuable adjuvant in the treatment of AD, especially in patients with relapses,” she said.
Past studies have reported an inverse relationship between 25(OH)D (vitamin D) serum levels and the severity of AD, noted Dr. Sanchez-Armendariz, who is with the National Autonomous University of Mexico in Mexico City. This finding makes sense, as vitamin D3 induces the topical production of antimicrobial peptides, which have direct antimicrobial activity and induce a host response characterized by cytokine release, chemotaxis, inflammation, angiogenesis, and re-epithelialization, she added.
Consequently, 25(OH)D deficiency has been posited as a culprit in the pathophysiology of AD. However, scientific and endocrine societies have published differing recommendations about safe and optimal doses for vitamin D3 supplementation, while experts have noted that 5000 IU per day is needed to achieve an increase of 10 ng 25(OH)D per mL serum (J Am Board Fam Med. 2014 Jul-Aug;27[4]:495-509).
For the study, therefore, Dr. Sanchez-Armendariz and her associates evaluated this dose as adjuvant therapy in patients with moderate to severe AD despite topical hydrocortisone aceponate, soap substitute, and emollient. Patients continued this usual care and received either a cellulose capsule placebo or 5000 IU oral vitamin D3 per day. Based on previously recommended cutoff values, the researchers considered serum 25(OH)D levels sufficient if they exceeded 30 ng per mL, insufficient if they were between 20 and 30 ng per mL, and deficient if they were less than 20 ng per mL (J Bone Miner Res. 2011 Mar;26[3]:455-7).
At baseline, the placebo and intervention groups resembled each other in terms of baseline levels of 25(OH)D, calcium, and phosphorus, pruritus, and scores on SCORAD and the six-area Total Body Severity Assessment. A total of 59% of patients had insufficient serum 25(OH)D, and 39% were deficient.
Patients in both groups improved on the Total Body Severity Assessment, but the extent of improvement did not statistically differ between groups, Dr. Sanchez-Armendariz reported. Supplementation did significantly increase serum 25(OH)D levels, which at week 12 averaged 58.3 ng per mL (SD, 18.5 ng per mL), compared with 22.2 (SD, 7.6 ng per mL) with placebo (P less than .001).
Interestingly, at week 12, all patients in the vitamin D3 group achieved serum 25(OH)D levels of at least 30 ng per mL, as did 41% of patients in the placebo arm. Patients in both groups who achieved this “sufficient” serum 25(OH)D level averaged a nearly 21-point improvement on the SCORAD (SD, 11.1 points), compared with 7.5 points (SD, 9.9 points) among patients who remained deficient, and 17.4 points (SD, 12.7 points) among patients who remained insufficient (P = .004 for difference among groups; P = .02 for difference between sufficient and insufficient groups).
An analysis of variance confirmed this finding, showing that, regardless of treatment group, patients whose final serum 25(OH)D level was at least 20 ng per mL scored an average of 20 points on the SCORAD, compared with 38 points for patients whose 25(OH)D level remained below 20 ng per mL. Patients whose final 25(OH)D level exceeded 20 ng per mL had fivefold greater odds of having a SCORAD below 25 than did patients with lower serum 25(OH)D levels (odds ratio, 5.1; 95% confidence interval, 1.2-22.6; P = .03).
The investigators identified no adverse effects of vitamin D3 supplementation, Dr. Sanchez-Armendariz said. “Attaining 25(OH)D levels above 20 ng per mL in addition to baseline therapy reduced the SCORAD of patients with moderate to severe atopic dermatitis,” she added. Clinicians should consider vitamin D3 deficiency and supplementation in patients with relapsing or refractory AD, she emphasized.
Dr. Sanchez-Armendariz reported no external funding sources and no conflicts of interest.