Sunlight and Vitamin D

There are a lot of questions that surround sunlight and vitamin d and it is difficult find definitive answers on how to receive the most beneficial amounts for each of our unique body systems. Because of this in my humble opinion there are no definitive answers, but there is a lot that we do know that can help each one of us find our own answers if we’re willing to look for them. Much like the questions that arise regarding diet and nutrition we are all different to some degree biologically and physiologically which are large factors in how much sunlight we need to keep in homeostasis- (the balancing act our bodies are constantly playing to keep us healthy and free from disease).

Although we refer to vitamin D as a vitamin, about 30 years ago while searching for a cure for rickets it was discovered that It’s actually a hormone.

What’s a Hormone?- A hormone is a substance that is produced in one part of the body, enters the bloodstream and exerts it’s effects at sites distant from the original site of production. It is also a chemical messenger that transports a signal from one cell to another. All multicellular organisms produce hormones.

What’s a Vitamin?- A vitamin is an organic compound required as a nutrient in tiny amounts by an organism. A compound is called a vitamin when it cannot be synthesized in sufficient quantities by an organism, and must be obtained from the diet. Vitamins have diverse biochemical functions, including function as hormones (e.g. vitamin D), antioxidants (e.g. vitamin E), and mediators of cell signaling and regulators of cell and tissue growth and differentiation (e.g. vitamin A)

I’ve read some books based on this finding that “Vitamin D is not a vitamin but a hormone”. However it appears to have qualities of both vitamin and hormone, implying how incredibly important this substance is to our physiology, biochemistry and even psychological balance. Although we can obtain vitamin D from food I’m going to focus this article on mainly on sunlight, which is one way we obtain vitamin D and its many benefits to keep things more simple (for both of us). Vitamin D and food will be in a later article.

I feel it’s important to know how the vitamin D our bodies use is produced, so take a deep breath and here we go.

Vitamin D is produced in the skin from pro-vitamin D3 which is derived from cholesterol. Here is evidence that cholesterol is not all bad, contrary to what most people think. In fact cholesterol is a precursor for most hormones in your body. Type B Ultraviolet rays (UVB) from the sun act on pro-vitamin D3 and convert it into pre-vitamin D3, which is then converted into vitamin D3. Vitamin D3 then leaves the skin and gets into the blood stream where it is carried on a special protein called a vitamin D-binding protein. Through blood circulation, vitamin D3 reaches various organs in the body. In the liver, vitamin D3 undergoes a slight change in it’s chemical structure. At that point it’s called 25 (OH) vitamin D3. It is then carried through the bloodstream to the kidneys where it goes through another change in its chemical structure. At that point it’s called 1,25 (OH)2 vitamin D3. This is the active form of vitamin D. It goes back to the blood stream and goes to various parts of the body and exerts its actions (more actions than is known by modern science safe to say). This is why vitamin D was re defined as a hormone.

The lesson here is that the vitamin D obtained from sunlight or food goes through several changes before it’s transformed into a substance we can use. The above scenario is assuming that your organs are functioning optimally and your source of vitamin D is bioavailable (viable and able to be absorbed by the body) which in these modern times with troubled food sources and environmental challenges to the system is often not the case. Much of the D sources we take in can be lost for this reason. So don’t assume if you’re taking the RDA from the FDA by way of a supermarket multivitamin that your not deficient in vitamin D. A 2000-2004 National Health and Nutrition Examination Survey reported that 50-78% of Americans suffer from Vitamin D deficiency. In the U.K. a national data collection survey in 1988-1994 showed 90% of adults to be found low in vitamin D.

So what happens if I don’t have enough vitamin D? In his book “Power of vitamin D” Safraz Zaidi MD links vitamin D deficiency as a factor to not only degenerative arthritis and Osteoporosis but also: body aches and pains, chronic fatigue syndrome, hyperparathyroidism, low immune system and the common cold, asthma, tuberculosis, lupus (SLE), M.S., type 1 diabetes, hyper- and hypo- thyroidism, inflammatory bowel disease, ulcerative colitis, crohn’s disease, heart disease, cancer, and hypertension.

Realizing the power of vitamin D as a hormone affecting so many bodily functions and systems helps us to realize how this could be possible, that so many disorders could be linked as a factor to a single deficiency such as this.

Some of the most amazing and startling findings on sunlight and its effects on humans, plants, and animals came from a man named John Ott. If you’ve heard of an ott light (which is a full spectrum light bulb), it’s named after him. He developed time lapse photography. All those cool films showing flowers growing from seed or fruits growing from flower to something big red and juicy that take weeks or months to happen in real time; he developed a method of showing that growth spurt in half a minute on film.

During the time as he was developing his filming methods he was continually asked to film this vegetable, flower or plant during it’s growth process from sprout to bloom or fruit which in order to film this long process had to be in a controlled environment often with artificial lighting. What he discovered was that the growth process was altered depending on the type of light being used, if color filters were used, or if he allowed sunlight to pass through glass or clear plastic pains. He was suffering from debilitating arthritis in his hip during this time and wore glasses. Inspired by his discoveries in working with plants he began giving himself sunlight therapy part of which involved removing his glasses and allowing unfiltered sunlight to enter through his eyes and his skin, and effectively completely reversed his arthritis and found it unnecessary to wear his glasses. (Sunlight therapy is a healing practice that has been well documented as having been used as early as pre Roman- Greece.)

He began conducting his own research with sunlight, including using time lapse photography to show the effects of sunlight on the cellular level through a microscope. These experiments showed cells moving in chaotic and distorted patterns when different parts of the light spectrum were cut out using different colored filters or glass. He spent the rest of his life with much support from leaders in the medical community lobbying to have research conducted that could be published and accepted by western science on his findings. This of course never came to pass, since if it were shown that sunlight could cure many of todays most baffling and destructive diseases it would take a huge bite out of the billions in profits enjoyed by the pharmaceutical industry. However he was awarded an Honorary Doctorate of Science Degree from Loyola University of Chicago, authored many books and articles, produced a film of some of his work, gave literally thousands of lectures at conferences, scientific symposiums and to the general public over the years, including lectures to the Cancer Control Society. So his lifes work lives on. His work also showed that like plants, animals and humans evolved with and have a need for the full spectrum of sunlight to have all their systems function properly.

Consider this. In 1900 more than 75% of the population in the U.S. worked outdoors, while in 1970 less than 10% did. I can’t imagine what the current percentage is in 2011.

In the 1930’s sunlight therapy was very popular and a doctor named August Rollier who was director of a sunlight therapy clinic in Leysin, a town high in the Swiss Alps, attributed the therapeutic action of the sun to it’s ultraviolet rays. This clinic was built at a 5000 foot elevation to allow maximum exposure to U.V. rays for their therapies. They had patients who were completely cured of tuberculosis (among other diseases) and one doctor at the clinic discovered that the sunlight had no affect on patients who wore sunglasses. This is one among many reported examples of how important it is to receive natural full spectrum sunlight through the eyes in addition to the skin when possible.


There is much research showing how harmful and dangerous the sun is and we’re sold many products to help protect us from the “dangerous” sun because of “the increase in U.V. rays from our depleted ozone”. Dr. Ott said it best when he stated “If you stick your hand in a furnace it’s going to get burned. But this doesn’t mean you should avoid heat completely and keep your house at absolute zero! The public has to understand that light is a nutrient just like a vitamin or a mineral. Trace amounts of ultraviolet radiation are as important to people as trace amounts of vital nutrients.”

I could go on and on about the benefits of sunlight and some people have (take a look below at the books which were sources for this article). One of the most important aspects of receiving adequate sunlight on a daily basis in my minds eye is the synthesis of vitamin D. So I encourage you to do your own research and read some of the sources I list at the end of this article. Here are some helpful practices regarding sunlight that will help boost your vitamin D level among other health benefits:

1. Spend as much time as you can outdoors every day regardless of the weather. (1hour minimum is suggested). Even on a cloudy day or being in the shade (which is said to reduce U.V. rays by aprox. 50%) is extremely beneficial. Other considerations on this are:

The further north you are from the equator the less is the intensity of the sun rays reaching earth.

The hours between 10am and 2pm (aka the burning hours) should be utilized with caution. Sunburn damages skin cells and dna and is thought to cause skin cancer. If you have fair skin it might be best to avoid direct sunlight during these hours completely.

2. Regarding suntan lotion- SPF 8 blocks 95% of U.V. rays thus nullifying the benefits of skin exposure to the sun. Also a recent report from the U.S. Food and Drug Administration concluded that fourteen out of seventeen suntan lotions containing PABA can be carcinogenic when exposed to the sun. Additional research indicates that PABA can cause genetic damage to the DNA in the skin. It might be advisable to use no suntan lotion and gradually build your time in the sun. Other ingredients to avoid include Benzophenones, Cinnamates, Salicylates, Digalloyl trioleate, Menthyl anthranilate, and Avobenzone. All found in most commercial sunscreens.

3. Ordinary window glass blocks almost 100% of short wave U.V. and this distorted light spectrum has in fact been implicated (by Dr. Ott and others) to cause a myriad of developmental issues in plants and animals especially by exposure through the eyes. How many hours a day do you spend wearing glasses that don’t have full spectrum lenses or looking through the windshield of a car?

4. The skin of an elderly person is said to produce 25% less vitamin D to that of a young person, so more exposure to sunlight may be advisable.

5. The color of your skin comes from a pigment called melanin. Melanin serves as a natural sunscreen and blocks sunrays from getting into deeper layers of your skin. Therefore although sunburn is less of a danger if you have darker skin the need for longer exposure to sunlight to get the same benefits as a person with fair skin would be necessary. For example an African American would need to spend about 10x’s the amount of time in the sun as compared to a fair skinned person to receive the same benefits.

I hope you’ll find these suggestions useful and are able to spend more time outdoors honoring the star that gives our planet life.


In Gratitude-

Shawn Kinsella LMT,CA,PYT


Sources for this article include:

“Light Medicine of the future” by Jacob Liberman, O.D. PH.D.

“Power of Vitamin D” By Sarfraz Zaidi, MD

“Health and Light” by John N. Ott