Have any supplements been studied for autism spectrum disorder?

Many dietary supplements have been investigated as potential treatments for ASD, including omega-3 fatty acids,^[1] melatonin,^[2] vitamin-d,^[3] and a combination of vitamin-b6 and magnesium.^[4] There appears to be little evidence for omega-3 supplementation and some conflicting evidence for vitamin B6 and magnesium cosupplementation in treating the core symptoms of autism. However, correcting low vitamin D status through supplementation shows some promise, and melatonin appears to improve some sleep parameters, thus improving daytime behavior.