LewRockwell 
Sleeping well is an essential strategy to optimize your health, and at the heart of it is your circadian rhythm. This is also known as your body clock. It’s a natural, biological timer present in every one of your cells that helps your body recognize sleepiness and wakefulness over a period of 24 hours.
Your circadian rhythm is largely dictated by your pineal gland, located near the center of your brain, which produces melatonin, a hormone that is crucial for the regulation of your sleep cycle.
If you have had enough exposure to bright light in the daytime, your pineal gland typically starts secreting melatonin around 9 p.m.1 As the amount of melatonin in your brain increases, sleepiness sets in as your body begins to prepare for sleep.
If you stay awake past dark, artificial light — especially that emitted by electronic devices — will inhibit your body’s melatonin production, so, ideally, you would stop using electronics at least an hour or two before bedtime to help increase melatonin production and maintain a steady circadian rhythm.
Melatonin Does More Than Control Sleep
While melatonin works as a natural sleep regulator, its biological effects don’t end there.2 It’s also a potent antioxidant3 that plays an important role in cancer prevention.4 It’s also thought to be important for brain, cardiovascular and gastrointestinal health,5 and has been shown to boost your immune function in a variety of ways.
In one study,6 researchers suggested melatonin may even improve the treatment of bacterial diseases such as tuberculosis. In another, melatonin was identified as a potential tool against inflammation and autoimmune diseases, including Type 1 diabetes.7
Melatonin is also an important energy hormone. As noted in the Stanford University course paper “Melatonin and Energy Levels:”8
“… decreasing the melatonin in the blood stream, consistent with the body’s natural response to suppress the secretion in the presence of light, causes the body to function at a higher energy level … An increase in the melatonin levels leads to a subsequent decrease in energy levels.
As such, understanding how to control and optimize the secretion and suppression of the melatonin for optimal hours of the day could help improve the treatment of sleep disorders and positively impact the energy levels of individuals.”
In short, if your sleep efficiency is impaired, meaning you’re not sleeping as deeply as you should, for as long as is ideal, then your energy level is going to be adversely affected.
Conversely, spending most of your daytime hours in poorly lit rooms, especially if you’re also exposed to excessive light after sunset, can impair your melatonin production, causing you to not sleep well.
Melatonin Protects Your Mitochondria
Importantly, the antioxidant activity of melatonin also helps protect your mitochondria, the tiny organelles inside your cells that generate most of the ATP or energy currency of your body. As noted in a 2007 paper in the Frontiers of Bioscience:9
“Melatonin is an ancient molecule present in unicellular organisms at the very early moment of life … The best-known actions of melatonin, currently supported by experimental and clinical data, include antioxidant and anti-inflammatory abilities, some of them involving genomic regulation of a series of enzymes.
Besides, melatonin displays anticonvulsant and antiexcitotoxic properties. Most of the beneficial consequences resulting from melatonin administration may depend on its effects on mitochondrial physiology.”
In fact, melatonin appears to be the most powerful antioxidant in this regard, as it has the ability to actually enter into your mitochondria.10 This is an ability that not all antioxidants have. According to this Frontiers of Bioscience paper,11 melatonin helps “prevent mitochondrial impairment, energy failure and apoptosis in oxidatively-damaged mitochondria.”
One of the things that makes melatonin so powerful is that it doesn’t just act as an antioxidant in and of itself; it also interacts with your body’s innate antioxidant system where it recharges glutathione.12 However, this brings us back to the importance of sleep.
Since melatonin is only released in response to darkness, and is easily and significantly inhibited by light (such as regular room lighting and electronic screens, after dark), your mitochondrial health will suffer if you do not take steps to optimize your sleep.
Aside from worsening your sleep quality and decreasing your sleep quantity, low melatonin production also increases oxidative stress, speeds up the aging process and raises your risk of degenerative diseases and chronic fatigue, thanks to its influence over your mitochondria.
Melatonin Works Synergistically With Vitamin D
In my February 2, 2020, article “The Importance of Vitamin D for Optimal Sleep,” which features my interview with neurologist and sleep coach Dr. Stasha Gominak, I review the hidden influence vitamin D has on your sleep.
A paper13 that will be published in the May 2020 issue of The Journal of Steroid Biochemistry and Molecular Biology — which I was able to review early, parts of which I’m sharing with you here — sheds further light on this connection. Not only does melatonin enhance vitamin D signaling, the two molecules act synergistically to optimize your mitochondrial function.
As noted in this paper,14 “The biosynthetic pathways of vitamin D and melatonin are inversely related relative to sun exposure,” meaning both are dependent on properly timed exposure to the sun.
A hypothesis presented by the researchers is that vitamin D and melatonin “play an essential role as modulators of mitochondrial function and adaptation to circadian and seasonal variations.”
Additionally, “both molecules are involved in the homeostatic functioning of the mitochondria,” the authors point out, stressing that the mitochondria are, in fact, “the final common target for melatonin and vitamin D.” Furthermore:
“A deficiency of these molecules has been associated with the pathogenesis of cardiovascular diseases, including arterial hypertension, neurodegenerative diseases, sleep disorders, kidney diseases, cancer, psychiatric disorders, bone diseases, metabolic syndrome, and diabetes, among others.
During aging, the intake and cutaneous synthesis of vitamin D, as well as the endogenous synthesis of melatonin are remarkably depleted, therefore, producing a state characterized by an increase of oxidative stress, inflammation, and mitochondrial dysfunction …
Mitochondrial dysfunction has been related to the etiologies of many complex diseases where overactivation of the renin-angiotensin-aldosterone system (RAAS), vitamin D deficiency and the reduction of melatonin synthesis converge.
In this sense, experimental and clinical evidence indicates that inflammation, oxidative stress, as in mitochondrial dysfunction, are consistent with low levels of melatonin and vitamin D, and also represent risk factors connected with development and maintenance of prevalent acute and chronic pathologies.”
Melatonin-Vitamin D Combo Produces Strong Synergistic Effects
According to the 2020 paper in The Journal of Steroid Biochemistry and Molecular Biology,15 multiple sclerosis, cancer, neuropsychiatric disorders and high blood pressure are all examples of diseases that appear strongly linked to and affected by your vitamin D and melatonin status.