Hi Dr Dennis.. Melatonin has many important functions in humans..

Maintain sleep awake cycle and circadian rhythm

Antioxidative and scavenging property

Improves immune function

Anti aging property

Maintain skin color

Low level of melatonin is associated with increased risk of epilepsy, ischaemic heart disease, multiple sclerosis and post menopausal osteoporosis.. Thanks

Melatonin ( a hormone produced in the pineal gland of the brain) has many important roles in the human physiology: regulator of the circadian rhythms, sleep inducer, antioxidant, anticarcinogenic.

Melatonin receptors are found in the suprachiasmatic nucleus (SCN) and the pituitary gland of the brain, as well as in the ovaries, blood vessels, and intestinal tract. There is a high concentration of receptors in the SCN because this is where melatonin mediates the majority of its affects on circadian rhythm.

• Melatonin has strong antioxidant effects ( supplemental melatonin restores normal, youthful levels of the hormone, and provides powerful antioxidant protection for the brain).
• Melatonin also has incredible neuroprotective effects (studies now reveal that melatonin levels begin to decline at just the time when neurodegenerative diseases begin to rise, and there’s good scientific evidence for a strong connection between these phenomena).
• Laboratory and early clinical studies show that melatonin supplementation can protect against the age-induced brain changes leading to Alzheimer’s and Parkinson’s diseases, to increased stroke risk, and to susceptibility to brain trauma.
• Some research suggests that melatonin may help elderly people with insomnia who are tapering off or stopping benzodiazepines such as diazepam (Valium), alprazolam (Xanax), or lorazepam (Ativan). Taking controlled-release melatonin improved sleep quality in those stopping benzodiazepine use. More research is needed.

Best regards

Season's Greetings and best wishes for the New Year! ;-) and not to have a lack of melatonin!