Between the ages of 1 and 3, we have the highest levels. As we age, we produce and secrete less. When melatonin levels get too low, we may become sleep-deprived, which might be one reason that so many people over age 65 suffer from chronic insomnia. Melatonin is also present in some plant and animal foods, although in very small amounts. Bananas have it, but you d have to eat 40 at one sitting to get one milligram of melatonin .
Supplements are the only source of significant concentrations.
When scientists isolated this hormone of darkness, they naturally began to wonder whether it could change sleep patterns. Today, melatonin is widely available as a supplement, and while some researchers think it may have many other properties, the most widely accepted use is for sleep- related problems. When taken in proper doses at the appropriate time of day, this hormone can indeed increase sleepiness and help you fall asleep, says Irina Zhdanova, M.D., Ph.D., principal research scientist for the brain and cognitive sciences department at the Massachusetts Institute of Technology in Cambridge. Studies have shown that people who take melatonin may fall asleep faster, are less susceptible to awakening during the night, and feel that their sleep is more restful. Supplementing with melatonin is not like taking a sleeping pill, however.