Effects of Omega-3-6-9 fatty acid supplementation on behavior and sleep in preterm toddlers with autism symptomatology: Secondary analysis of a randomized clinical trial

•This randomized clinical trial explored effects of omega 3-6-9 supplementation on behavior and sleep.•Omega 3-6-9 supplementation showed benefit on internalizing and interpersonal relationship behaviors.•No effect of omega 3-6-9 supplementation on toddler sleep was identified.•Findings provide preliminary support for further exploration of omega 3-6-9 supplementation.•Investigation in larger preterm samples of children is needed.