Melatonin is a natural hormone nutrient that issynthesized from the amino acid tryptophan by thepineal gland in the back of the brain. Melatonin alsooccurs in small amounts in a variety of foods. In thebody, melatonin appears to regulate sleep/wakecycles, support normal immune function and protectcells from free radical damage.
Most of the research on melatonin has focused on itsrole in maintaining normal sleep/wake rhythms. Theperception of daylight in the eyes is a signal for thepineal gland to inhibit melatonin synthesis andrelease. At night or in the dark, the body's melatoninproduction rises. The rise in plasma melatonin isthought to be responsible for bringing on sleep.Nocturnal melatonin production is highest in childrenand begins to decline from adolescence on until it isvirtually absent in the elderly.
Melatonin supports normal immune function byhelping maintain the activity of circulating naturalkiller cells. It also has been found to function as anantagonist for stress-induced immunosuppression.
Melatonin is considered a potent antioxidant thatenters all body cells to help prevent free radicaldamage. In the brain, melatonin is perhaps the mostimportant physiological antioxidant. Due to its lipidand water-soluble properties, it can freely cross theblood-brain barrier. In vitro studies show thatmelatonin is more effective than glutathione inscavenging toxic hydroxyl radicals, and also moreefficient than vitamin E in neutralizing peroxylradicals which can induce DNA damage.Furthermore, melatonin stimulates the mainantioxidant enzyme of the brain, glutathioneperoxidase.
Adults take 1 tablet daily or as directed by physician.