According to Mercola.com, production of vitamin D3 in the skin varies by individual and depends upon several factors.

Each of the factors listed below can affect the production of vitamin D when trying to metabolize it naturally from the sun.
Skin color (including current tan level): Paler skin will hit an “equilibrium point” after about 20 minutes of exposure to UVB light, at which point vitamin D will no longer be produced. For darker skin, reaching this equilibrium point can take two to six times longer (or up to an hour or two), depending upon pigmentation.
Amount of time spent in the sun: A light-skinned person living far from the equator (such as in the UK or the northern U.S.) needs at least three 20 minute sessions per week, in bright midday sunlight and with few clothes. A dark-skinned person should be outside significantly longer and more often to get the same effect.
Weather conditions: Clouds can prevent some UV radiation from reaching the earth’s surface, but it is still possible to get sunburned on a cloudy day. This is especially true under light clouds, which can block infrared (heat) radiation but not UV radiation. Air pollution can also block UV radiation. This can be particularly true of cities surrounded by hills or mountains, which trap air pollution. Some types of ground cover reflect UV radiation, increasing its intensity even in deceptively shaded areas. These surfaces include sand, snow, and water.
Latitude: Sunlight is strongest at the equator, where the sun is directly overhead rather than at an angle. The UV radiation at the equator is about four times as strong at the equator as it is at the Arctic and Antarctic circles.
Altitude: UV radiation is also more intense at higher altitudes, because there is less atmosphere to absorb it. You will burn more easily at high altitudes — a fact that is often overlooked because it is usually colder at higher altitudes.
Season: Always start “priming” your skin early in the spring when the sun’s rays are still mild. In summer, avoiding being outside when the solar radiation is most intense is a good idea at most latitudes, to avoid sunburn. The winter is the time of year when you need to be most concerned about the amount of vitamin D you are receiving. Vitamin D levels can drop by up to 50 percent during winter months.
Time of Day: The optimal time to be in the sun for vitamin D production is as near to solar noon as possible. That would be between 10:00 am and 2:00 pm. During this time you need the shortest exposure time to produce vitamin D because UVB rays are most intense.

You need to be very careful about the length of your exposure.  This may only be a few minutes for some. Once you’ve reached your equilibrium point your body will not make any additional vitamin D. Any additional exposure will only cause harm and damage to your skin.

1) http://www.mercola.com/

According to research published online April 18, 2012, in the British Journal of Dermatology, using the amount and sun protection factor (SPF) of sunscreen recommended by the World Health Organization (WHO) is associated with little or no vitamin D production, suggesting that regular sunscreen use may lead to vitamin D deficiency.

The study demonstrated that the vitamin D serum level in the blood of the test subjects increased in an exponential manner with decreasing the thickness of sunscreen layered on their skin in response to UVB exposure. According to the researchers, “the results suggest that sunscreen use according to the current recommendations by the WHO may be re-evaluated.”¹

The use of sunscreen with a sun protection factor (SPF) of just 8 inhibits more than 95% of vitamin D production in the skin.²

Recent studies showed that following the successful “Slip-Slop-Slap” health campaign encouraging Australians to cover up when exposed to sunlight to prevent skin cancer, an increased number of Australians and New Zealanders became vitamin D deficient.²

The argument for safe sun exposure to facilitate natural vitamin D production is a growing one. SkinHealth Technology has developed a patented, new sensor that helps enable the user to get sun for vitamin D optimization without damage to the skin.

1) http://www.doctorslounge.com/index.php/news/pb/28609
2) http://en.wikipedia.org/wiki/Potential_health_risks_of_sunscreen

Recently, Dr. Stephanie Seneff, a senior scientist at MIT was quoted in an article by Dr. Joseph Mercola, entitled “How Can Sunscreen Cause Alzheimer’s?” Seneff, a senior scientist at MIT who has a wealth of information about the importance of sulfur, explains:
“… depletion of sulfate supply to the brain is another important contributor to Alzheimer’s, and I further think that sulfate is supplied to the brain principally by sterol sulfates like cholesterol sulfate as well as their derivatives like vitamin D3 sulfate. Both cholesterol sulfate and vitamin D3 sulfate are synthesized in the skin upon exposure to sunlight, and it is theorized that the skin is the major supplier of these nutrients to the body. This is why I believe that excess sunscreen use and excess sun avoidance are another principal causative factor in Alzheimer’s disease.”¹

The argument for safe sun exposure for overall health is a growing one. The question is how much sun is too much?
SkinHealth Technology has developed a patented, new sensor that helps enable the user to get sun without damage to the skin.

The Natural Vitamin D UV Activation Sensors take the guess work out of gauging the real-time intensity of UV light and answers the universal “how long should you stay in the sun without sun protection” question.

1) http://articles.mercola.com/sites/articles/archive/2012/03/03/sun-screens-cause-alzheimers.aspx

Spring is here and with much of the country experiencing above normal temperatures people are enjoying outdoor activities extra early this year.  Experts in the medical field agree that spending a short amount of time in the sun (without sun protection) is actually good for you.  A certain amount of exposure to natural UVB light allows the body to produce vitamin D naturally. This critical nutrient is essential to overall health and the best way to obtain it is from the sun.

According to Dr. Oz, “Vitamin D boosts your immunity, promotes healthy neuro-muscular functions and helps protect you from some forms of cancer. The easiest way to reap the benefits of this nutrient is to spend 15 minutes in the sun a few times a week. Be mindful that sunscreen will prevent you from getting adequate vitamin D outdoors; try skipping sunscreen for just 15 minutes.” ¹

This is great advice, but with variables like time of day, time of year, geographic location, etc—it’s evident that 15 minutes in Maine is not going to equate to 15 minutes in Miami! So how do can you know when you’ve had enough sun to attain your vitamin D?

A small sensor that enables the user to identify when they have spent enough time–without burning–is now available from SkinHealth Technology. ‘Natural Vitamin D UV Activation Sensors’ adhere to clothing or skin. When the color changes from yellow to red–optimal vitamin D development has taken place and indicates it is time to apply sunscreen or seek cover.

SkinHealth Technology developed Natural Vitamin D Sheer Sunscreen as ‘step two’ and is designed to be applied to the skin as soon as the sensor indicates vitamin D optimization. The sunscreen immediately begins protecting the skin.

1) http://www.doctoroz.com

A study presented last month at the annual meeting of the American Academy of Orthopedic Surgeons reported that blood levels of vitamin D were “insufficient” in 78% and “frankly deficient” in 39% in patients treated for a fracture at a Missouri trauma center.

The researched group of 889 patients excluded those with known risk factors for vitamin D deficiency. As reported in the New York Times by columnist Jane E. Brody, vitamin D levels are often associated with bone health, but deficiency in this vital hormone (not really a vitamin) risks many other serious illness.¹ With potential ramifications as diverse as diabetes, heart disease and a host of cancers, it’s worth keeping your vitamin D level in check.

Vitamin D is difficult to attain through diet. In fact, only a handful of foods like mushrooms, oily fish and enriched milk or orange juice provide any vitamin D at all. Supplements can help keep your D levels up, but the best source of Vitamin D is the sun.

Skincare experts at SkinHealth Technology, LLC have developed a patented, new concept that enables you to attain vitamin D 100% naturally – without damage to the skin. To accurately gauge the necessary length of time in the sun, simply apply one of the Natural Vitamin D UV Activation Sensors to skin or clothing. When the sensor turns red and the sun symbol disappears —it’s time to apply sunscreen or get out of the sun.

1)   http://well.blogs.nytimes.com/2012/03/12/reasons-to-place-a-bet-on-vitamin-d/

According to a study published in the weekly issue of Deutsches Ärzteblatt International (the German Medical Association’s official international bilingual science journal) researchers found that most of the geriatric patients in a German rehabilitation hospital suffered vitamin D deficiency. The study measured ‘25-OH vitamin D’ in 1,578 patients after admission to the rehab hospital.¹

Of the residents, 89% were found to have insufficient high concentrations of vitamin D and 67% had severe vitamin D deficiency. According to Deutsches Ärzteblatt International, insufficient vitamin D can negatively affect muscles and increase risk for falls and fractures in elderly people.¹

The most effective way to obtain this vital nutrient is to get your vitamin D from the sun directly.  However, the elderly produce less vitamin D in their skin than younger people and they spend less time in the sun. ¹

The current RDA for vitamin D–by the National Institutes of Health–is 800 IU’s for individuals 70 years and older.³ Many experts contend that this is not an adequate amount for overall health.

Although vitamin D is conventionally known to be important for bone health, vitamin D deficiency has been associated with serious health conditions including heart disease, diabetes, and depression and many as seventeen types of cancers, including breast cancer.²

1) aerzteblatt.de
2) Vitamin D Council
3) Office of Dietary Supplements

Plaque psoriasis is a skin disease that has been long known in humans. It is categorized as an autoimmune disease, but according to Dr. Michael F. Holick, a leading authority on vitamin D and author of The Vitamin D Solution, this may not be completely accurate. His research has led him to believe that the disease begins with a defect in the skin cells that causes them to reproduce out of control, thus calling on the immune system to respond, making the problem worse.

Treating psoriasis with drugs that suppress the immune system doesn’t address the defective skin cells where the problem begins and these drugs are well known to have serious side effects.

In treating psoriasis, patients and doctors alike have long known that moderate sun exposure was useful in improving the condition, even before it was determined that vitamin D therapy would help. It is now understood that the sun exposure activates vitamin D in the skin which helps regulate the over-proliferation of skin cells.

Even though vitamin D from the sun can be a good thing, too much sun can be bad for psoriasis. If you are using sun exposure in your treatment regimen, you must be careful to gauge exposure in order to receive the optimum dose before becoming pink. SkinHealth Technology’s Natural Vitamin D UV Activation Sensors are a good way to ensure this.

Holick, Michael F. The Vitamin D Solution. New York, NY: Hudson Street Press, 2010. 109-112. Print.

According to Mercola.com:

Theories linking vitamin D deficiency to cancer have been tested and confirmed in more than 200 epidemiological studies, and understanding of its physiological basis stems from more than 2,500 laboratory studies.

Optimizing your vitamin D levels could help you to prevent at least 16 different types of cancer including pancreatic, lung, ovarian, prostate, and skin cancers. Overall, optimal vitamin D levels can cut cancer risk by as much as 60 percent, according to one large-scale, randomized, placebo-controlled study.

The most important factor is your vitamin D serum level. In order to help prevent a wide variety of diseases and health ailments, your vitamin D level needs to be between 50 and 70 ng/ml year-round.

The ideal way to optimize your vitamin D level is through sun exposure. As a very general guide, you need to expose a substantial amount of your entire body, when the sun is at its zenith.

According to recent findings from the D* Action study, adults need about 8,000 IU’s of oral vitamin D3 per day in order to get serum levels above 40 ng/ml.

Natural sunlight is the best source of vitamin D! UV sunlight is the fuel that enables the body to make vitamin D, but how long should you stay in the sun to optimize your Vitamin D without sun protection?

Skincare experts at SkinHealth Technology, LLC have developed a patented, new concept that enables you to attain vitamin D development 100% naturally–without damage to the skin. To accurately gauge the necessary length of time in the sun, simply apply one of their Natural Vitamin D UV Activation Sensors to skin or clothing. When the sensor turns red and the sun symbol disappears —it’s time to apply sunscreen or get out of the sun.

“New Year’s Day… now is the accepted time to make your regular annual good resolutions. Next week you can begin paving hell with them as usual.”
~Mark Twain

Samuel Langhorne Clemens, better known by his pen name, Mark Twain, was an American author and humorist – and cynic based on the quote above. New Year’s Resolutions don’t have to be impossible to keep, though. Once you have made the resolution, keeping it is easier if you have a plan that fits into your daily life.

With the New Year here, there is one resolution that is on almost everybody’s list – to get healthy. Help keep this resolution with an easy to follow plan that comes with a long list of benefits. This year resolve to increase your vitamin D intake from the sun.

Using Natural Vitamin D UV Activation Sensors by SkinHealth Technology is a great way to gauge the optimum time in the sun needed to develop vitamin D without going so far as to damage your skin. Vitamin D is well documented as being one of the most essential to human health and deficiency is epidemic.

In northern climates, you may have to wait until early spring to produce vitamin D from the sun. In that case, the sensors will remind you that a little sun is a good thing and you are sticking to that get healthy resolution. It doesn’t take long. Short periods of sun exposure two to three times a week will fortify your body with this critical nutrient. The sensor will tell you when you have had enough. Vitamin D developed this way lasts longer and contributes to overall wellness – so you can focus on the other items on your list!

A new study released by Harvard University credits vigorous exercise, at least 3 hours per week, with stimulating production of good cholesterol and vitamin D, thereby lowering the risk for heart attacks.  The all-male study was conducted over a period of ten years and concluded a 22% reduction in the risk of heart attack in the participants.

How can exercise produce vitamin D?

Well, it turns out it is not the running or soccer playing.The researchers believe the increased vitamin D levels came from doing these activities outdoors where the sunshine stimulates the body to produce it.

This time of year in the U.S., especially in the northern latitudes, natural vitamin D production wanes. This is because the UVB rays that trigger the internal reaction to create the vitamin become less prevalent due to shorter days, the angle of the sun and cloudy skies.

The good news is that your body can store a good portion of the vitamin D it produces during the warmer months to help carry you through the winter.  Remember though, it only takes 15 to 20 minutes to produce vitamin D from the sun at its peak.

While exercising outdoors, use the Natural Vitamin D UV Activation Sensors by SkinHealth Technology. They are a great way to tell when vitamin D is optimized and sunscreen application is appropriate.

So skip the gym and do your exercise outdoors whenever possible to get a double health punch!