Sunlight & Vitamin D


Sunlight & Vitamin D

One of the most important aspects of life on earth is the sun. It provides warmth and energy, making life as we know it possible. Humans have evolved to live with the sun. It not only supports the plants and vegetation that feed and shelter us, but it is also an integral part of our physiology.

Vitamin D synthesis is a well known by-product of sunlight exposure. It helps regulate a number of genes and hormonal reactions in the human body. It also plays a role in bone health, immune system function, inflammation, etc.

However, a number of other beneficial reactions also occur. Melatonin is produced when it is dark and stops when daylight reaches our eyes. This helps to regulate our sleep-wake cycle, and plays an important role in countering cancer, auto-immunity and inflammation.

Sunlight also supports nerve transmission by stimulating various compounds in the body. It promotes a number of local effects on the skin that help protect the skin from the damaging effects of the sun’s ultraviolet radiation.

There is no question that the sun can have damaging effects and even promote skin cancer. However, during the winter months, many Canadians receive very little sunlight exposure. Many of us go to work when it is dark, stay inside all day, and return home after the sun has already gone down.

To compensate, people often take vitamin D supplements. Although, as mentioned above, there is more to sunlight than Vitamin D. Vitamin D supplementation may have a number of benefits, such as in immune regulation, as well as benefits in cancer and depression. However, some studies have found that certain benefits result from sunlight exposure independent of its vitamin D effects.

Furthermore, supplementation may actually be aggravating in some situations. Vitamin D is converted into different forms in the body which can help regulate your immune system, and also suppress its function This may be a problem in some skin conditions and certain infections. It is therefore important that supplementation be done under the guidance of a knowledgeable health care practitioner who can advise the correct dosage and provide other treatments if necessary.

Sunlight can have a number of benefits beyond vitamin D. However, it can also have damaging effects, which should not be underestimated or ignored. Therefore, working with a health care practitioner to develop safe sun strategies is an important way to improve your overall health.

Dr. Brian Casteels is a Naturopathic Doctor who practices locally to improve health and well-being in the community. Web: