Have any supplements been studied for eczema?

Several supplements have and continue to be investigated for eczema, though at present, the only ones approaching credibility from clinical trials are vitamin D^[1] and probiotics.^[2] They are also mechanistically plausible. Vitamin D is known to help regulate the immune system and plays a role in the formation of filaggrin, which helps to maintain the skin's moisture barrier. Some probiotics play a significant role in regulating the immune system to reduce excessive inflammation, maintain the gut barrier and prevent further inflammation.