Have any supplements been studied for Alzheimer’s disease?

RCTs have assessed a number of supplements’ effects on established Alzheimer’s disease. This includes omega-3s, B vitamins (usually folic acid, vitamin B6, and vitamin B12), vitamin D, vitamin E, ginkgo biloba, L-alpha glycerylphosphorylcholine (alpha-GPC), Lion's mane mushroom, ginseng, saffron, and sodium oligomannate. For the most part, these supplements have only conflicting or limited evidence in favor of their use.