Besides for helping you stay regular, prunes pack in vitamin B6, calcium and magnesium, which are essential for melatonin production.The nutrients in dried plums — vitamin B6, calcium, and magnesium, to name a few — help make melatonin, the hormone that regulates sleep. Use prunes as a whole-grain toast topping, mix them into trail mix, or eat them on their own about 30 minutes before bedtime.