So far, vitamin D is the only essential nutrient that has convincing evidence for improving atopic dermatitis. In a meta-analysis, 4 trials found evidence for a meaningfully beneficial effect.[1] Two used 1,600 IU; one used 1,000 IU; and one used sun exposure in a subtropical climate. Two were in children, and two were in older populations. More high-quality research is needed to confirm these findings and determine the best scenarios for using vitamin D for atopic dermatitis.
Other nutrients have been lightly researched, but they’re not worth mentioning at present.
Probiotics and synbiotics One meta-analysis of randomized trials in children found evidence of a beneficial effect for participants in the ages 1–18 category, but the effect on participants younger than 1 wasn’t statistically significant or as large.[2] In particular, the most evidence for a positive outcome was found for mixtures of probiotics. However, the studies in general had a notable risk for bias, so more research will be needed to both confirm efficacy and clarify which combinations of probiotics are best. The meta-analysis only included studies where a dermatologist had evaluated the participants with the SCORAD method, which lends itself to a higher level of objective measurements but limited the number of studies. Another meta-analysis that included any trial that used probiotics to treat pediatric eczema found a general benefit, but again, multiple studies on particular strains or mixtures are needed before we can know how to optimally use probiotics. Finally, a meta-analysis looked at synbiotic (a combination of pre- and probiotics) supplements, and out of 6, a statistically significant benefit was found, but it’s unclear if synbiotics are superior to probiotics or which synbiotics are best.[3]
Pharmaceutical and supplement therapies for atopic dermatitis are largely centered around substances that modify immune response to reduce the effects of persistent inflammation.