Does Multivitamins actually make a difference, or is it overhyped?

The most rigorous recent evidence comes from the COSMOS trial, a large randomized study that found daily multivitamin supplementation modestly improved memory and cognitive function in older adults over multiple years of follow-up, corroborating earlier smaller randomized trials including in the Physicians' Health Study II. Weighing the data: Multivitamins looks an early-stage, lower-priority area for now — the evidence is only moderate (60/100), and its estimated impact (35/100) is on the lower end too.