Benefits of Sun Exposure Beyond Vitamin D Production
Evidence presented in the April-June issue of Dermato-Endocrinology8 confirms that exposure to the sun in appropriate and measured timeframes has a number of health benefits unrelated to vitamin D production, including:
Enhancing mood and energy through the release of endorphins Protecting against and suppressing symptoms of multiple sclerosis (MS) Treating skin diseases, such as psoriasis, vitiligo, atopic dermatitis, and scleroderma. UV radiation also enhances skin barrier functions Inducing nitric oxide (NO), which helps protect your skin against UV damage and offers cardiovascular protection, promotes wound healing through its antimicrobial effect, and has some anti-cancer activity Melatonin regulation through the "third eye" of the pineal gland photoreceptors Relieving fibromyalgia pain Standard treatment for tuberculosis 100 years ago, long before the advent of antibiotics Treating neonatal jaundice Can be used to sterilize your armpits and eliminate the cause of most body odor Treating Seasonal Affective Disorder (SAD) Synchronizing important biorhythms through sunlight entering your eye and striking your retina Regulating body temperature Protecting against melanoma and decreasing mortality from it May be effective in treating T Cell lymphoma
Low Vitamin D May Increase Your Alzheimer's Risk
In related news, a new analysis published in the journal Neurology9 found that low concentrations of vitamin D may increase your risk of cognitive decline and Alzheimer's disease. The review included 37 studies. Eight of them compared the Mini-Mental State Examination (MMSE) scores of subjects with less than 20 ng/ml vitamin D and those with greater than 20 ng/ml. Those with higher levels scored better. Six studies also confirmed that those with Alzheimer's had significantly lower levels.According to the authors:"These results suggest that lower vitamin D concentrations are associated with poorer cognitive function and a higher risk of Alzheimer's disease. Further studies are required to determine the significance and potential public health benefit of this association."
Guidelines for Safe and Effective Sun Exposure
While sun exposure is your best source for vitamin D, it's important to understand that not all sun exposure will allow for vitamin D production. Sunlight is composed of about 1,500 wavelengths, but the only wavelength that makes your body produce vitamin D are UVB-rays when they hit exposed skin. The UVB-rays from the sun must pass through the atmosphere and reach where you are on the earth in order for this to take place. This obviously does not occur in the winter for many of us in the U.S., but the sun's rays are also impeded during a fair amount of the year for people living in temperate climates.Due to the physics and wavelength of UVB rays, they will only penetrate the atmosphere when the sun is above an angle of about 50° from the horizon. When the sun is lower than 50°, the ozone layer reflects the UVB-rays but let through the longer UVA-rays.So how do you know if you have entered into the time of year for your location where enough UVB is actually able to penetrate the atmosphere to allow for vitamin D production in your skin?The first step is to determine the latitude and longitude of your location. You can easily do this on Google Earth, or if you are in the U.S. you can use the TravelMath Latitude Longitude Calculator to find your latitude and longitude. Once you have obtained that you can go to the U.S. Navy site to calculate a table to determine the times and days of the year that the sun is above 50 degrees from the horizon.Translated to the date and time of some places on the globe, it means for example: In my hometown of Chicago, the UVB rays are not potentially present until March 25, and by September 16th it is not possible to produce any vitamin D from the sun in Chicago. Please understand it is only theoretically possible to get UVB rays during those times. If it happens to be cloudy or raining, the clouds will also block the UVB rays. For a more detailed understanding of this, please view the following video, and/or read through the corresponding article.
Yes, There's an App For That!
Alternatively, if you have an iPhone or iPad you can download a free app called "D Minder," which will make all the calculations for you. It was made by an Apple developer who was motivated to simplify the process after he watched the video above.From a health perspective, it doesn't make much sense to expose your skin to the sun when it is lower than 50 degrees above the horizon because you will not receive any valuable UVB rays, but you will expose yourself to the more dangerous and potentially deadly UVA rays. UVA's have a longer wavelength than UVB's, and can more easily penetrate the ozone layer and other obstacles (like clouds and pollution) on their way from the sun to the earth. UVA is what radically increases your risk of skin cancer and photoaging of your skin. So while it will give you a tan, unless the companion UVB rays are available you're likely doing more harm than good and should probably stay out of the sun to protect your skin.During the times of the year when UVB rays are not present where you live you essentially have two options: You can use a safe tanning bed or oral vitamin D3.