Selenium is a cofactor for enzymes in the body that function to neutralize reactive oxygen species,[1] and low vitamin D levels are associated with increased inflammation.[2] Because observational studies have noted low selenium and vitamin D levels in people with a new diagnosis of Graves’ disease,[3] one randomized controlled trial tested the effects of selenium and vitamin D supplementation in participants with Graves’ disease who had low levels of these nutrients. The trial found that selenium and vitamin D supplementation in combination with standard drug therapy was better than the drug therapy alone for treating hyperthyroid symptoms in participants.[4]
Additional supplements that have been studied for use in Graves’ disease include antioxidants,[5] omega-3 fatty acids,[6] and probiotics.[7]