Our circadian rhythm and melatonin

Dr. Jennifer Luis, B.Sc., B.Ed., N.D.

Dr. Jennifer Luis, B.Sc., B.Ed., N.D.

Not just a solution for insomnia, this incredible hormone does much more. Made in the pineal gland of the brain, melatonin has been dubbed the “Connecting Chemical” because it links the mind, body and the environment. Release of melatonin is regulated by light and by biological age.

When the retina of the eye is exposed to light, lower amounts of melatonin are produced. Thus sleeping in a completely dark room can help to improve sleep quality through sufficient melatonin release. In winter when nights are longer, melatonin will be slowly released for longer periods of time than the summer. In healthy individuals, melatonin levels peak between 2-3am. One study showed that after 1 hour of light exposure at midnight, 67% less melatonin was produced.

Melatonin exerts regeneration and turn over of cells and immune health. This decline could influence various cancers and decrease immune function later in life. It is thought that people make 80% less melatonin once they reach adulthood as compared to peak levels at 2 years old. In order for the body to make melatonin protein is required, specifically the amino acid tryptophan with the help of vitamin B6.

Melatonin excess and deficiencies can cause more than just sleep disruptions. Certain pharmaceutical drugs (antidepressants, aspirin, ibuprofen and beta-blockers) interfere with production and cause lower level while daytime exercise can increase production. Excess melatonin can be linked to lack of a menstrual cycle, low thyroid and adrenal function (energy, weight gain) and low blood pressure. Some symptoms of low melatonin include anxiety and mood disorders, cold body temperature, heavy/painful periods and shorter cycles, lower immune function and some cancers.

Supplementing with melatonin can range from 0.1mg to 10mg per day. The general amount for sleep-related disorders is between 1-3mg and can be taken under the tongue or as a prolonged-release tablet. It is generally not advised to regularly give melatonin to children and teens. If too much melatonin is taken at a time, vivid dreams and a groggy sensation in the morning are the most typical symptoms. Melatonin levels are regularly tested as part of a comprehensive urine hormone test when evaluating sex hormones and adrenal function.