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Light is one of the pillars of health.  But it is less appreciated or underacknowledged than foods and exercise.   A person cannot survive without light.  Light provides vitamin D.  Human skin can make large amounts of Vitamin D when lots of skin is exposed and the sun is high in the sky.  Our bodies are designed to get Vitamin D they need by producing it when the bare skin is exposed to sunlight.  The part  of the sun’s rays that is important is ultraviolet B (UVB).

Exposure to sunlight is thought to increase the brain’s release of a hormone called serotonin.  At night, darker lighting triggers the brain to make another hormone called melatonin, which is responsible for helping you sleep. Without enough sun exposure, your serotonin levels can decline.  Sunlight also burns fat, and minimize the risk of obesity, diabetes, and heart disease.

However, you must not stay outside in the sun for too long,  because excess sun exposure is linked with increased skin cancer risk.


The subcutaneous white adipose tissue  (scWAT), which is the major fat depot in humans and a central player in regulating whole body metabolism, tend to shrink under the effect of the sun’s blue light.  The visible type of light that boosts attention and mood during the day.   If dysfunctional scWAT can lead to cardiometabolic disorders such as obesity, diabetes and heart disease.


The link between sunlight and depression has been recognized for many years.  Some of the receptors in the brain are receptors of Vitamin D, which means that Vitamin D is acting some way in the brain. These receptors are found in the areas of the brain that are linked to the development of depression. For this reason, Vitamin D has been linked with depression and with other mental health problems.

Vitamin D affects the amount of chemicals called monoamines, such as serotonin, and how they work in the brain.  Vitamin D may also increase the amount of monoamines which may help treat depression.  Lack of Vitamin D in the blood increases the likelihood that you will develop depression.  Studies have shown a high prevalence of Vitamin D deficiency in depressed patients, and some studies have shown high dose Vitamin D is helpful in decreasing of depression.


Each of us has an internal body clock that tells us when to be awake and asleep.  Light is  important for our circadian rhythms.   Seasonal changes in sunlight affect our  circadian rhythms, which are referred to as our  internal biological clocks.  Less sunlight in the winter  is  thought to disrupt our circadian rhythm, causing depressive symptoms.  The Seasonal  Depression Disorder which some people experience in winter due to lack of sunlight is treated through light therapy.


Melatonin is a hormone that influences our sleep patterns and mood.   Experts believe that reduced exposure to sunlight through shorter days in winter disrupts our melatonin balance.  People with Seasonal Depression Disorder also have decreased serotonin levels during the winter months.


Sunlight is thought to stimulate the hypothalamus, a part of the brain that controls sleep, mood, and appetite, all of which impact on how we feel.  Similarly, production of serotonin, a brain chemical  (neurotransmitter) that affect the mood, may be affected by low sunlight.  Long walk outdoors where there is sunlight could help Seasonal Depression Disorder.


The bright light therapy, also known as phototherapy, can help restore circadian rhythm.   A person sits in front of a special light for 30 to 90 minutes each day.  It is important to purchase a light box that is designed for treating Seasonal Depression Disorder.  Doctors say exposure in the mornings tends to give the best result.

A similar treatment known as dawn simulation, when a special light in the bedroom is programmed to get slowly lighter in the mornings, to stimulate dawn.   Experts say this type of phototherapy also help restore brain chemistry balance.


Making your environment summier and brighter help alleviate Seasonal Depression Disorder.   Examples include opening curtains or blinds, trimming trees around the house, and sitting closer to the window during day time. Even in winter you do get  some sun, and there’s more sunlight outdoors than indoors.  So getting out everyday for a long period in the open air may help.


Our ancestors never had the  clocks or watches.  They relied on the sun or light to know what time it is.   Even now you may be in a desert, where there’s no technology, but through the light you can determine the time, and count the number of days you’ve been there.


With the stressful current turmoil surrounding the shortage of power supply, which is characterized by the rapid increase in electricity tariffs and loadshedding, the renewable and sustainable energy is an alternative.   To avoid the stress people are shifting to a green way of living, which is much safer, healthier, affordable, environmental friendly and more sustainable.   Light as a source of solar power is playing a vital role in this stress-free way of living.


When it’s dawn you yarn for the new day.  When you see the light  you hope to be saved, you hope to be assisted, and fear goes away.   Hence light is associated with success.  You often hear people saying, “there’s a light at the end of the tunnel” , meaning success follows hardwork.


Light is life.   Where there is light there is life.   When a sick person, lying on the hospital bed, sees the light, he knows he is still alive – he lives another day.   When the sunset and the light is gone, when the darkness begin, you know that another day is gone.  You sleep hoping to see the light again, and when it does you full of joy.


Whenever you see the light you become curious to know what is there.   This is because all good things are done under the light.  You know there is a person or people you can talk to, ask questions and get answers.  You know you can get a direction if you lost.


  1. what an interesting post. I didn’t know before now that the light can actually help with depression. When I was in school, we were taught about the early morning sun producing vitaminD and sometimes we were put outside the morning sun to take in some vitamin D. Interesting right?. It’s is also true that light means hope and light means life and this is evident in the popular saying that at the end of a tunnel, there is always light.

    1. Hi Jackson ,

      Thank you for stopping by.   I appreciate your time and comments. 

      All the best. 


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