Sun exposure to the skin is the human race’s natural, intended, most effective and most neglected source of vitamin D.
Vitamin D sufficiency, along with diet and exercise, has emerged as one of the most important preventive factors in human health. Hundreds of studies now link vita-min D deficiency with significantly higher rates of many forms of cancer, as well as heart disease, osteoporosis, multiple sclerosis and many other conditions and diseases.
Sunshine is a free commodity. Humans make 90 percent of our vitamin D naturally from sunlight exposure to our skin – specifically, from ultraviolet B exposure to the skin, which naturally initiates the conversion of cholesterol in the skin to vitamin D3.
Few foods naturally contain or are fortified with supplemental vitamin D. For example, an 8-ounce glass of whole milk is fortified with 100 IU (international units) of vitamin D – just 10 percent of what the most conservative vitamin D researchers now say we need daily. In contrast, sun exposure to the skin makes thousands of units of vitamin D naturally in a relatively short period of time.
- While vitamin D supplements are an alternative means of producing vitamin D when regular, non-burning sun exposure is not possible, oral supplementation of vitamin D is not nature’s intended means of producing this vitamin.
- While overexposure to sunlight carries risks, the cosmetic skin care industry has misled the public into believing that any UV exposure is harmful. No research has shown that regular, non-burning exposure to UV light poses a significant risk of skin damage.
- Humans spend less time in the sun today than at any point in human history – which is why more than 1 billion people worldwide are vitamin D deficient.
Vitamin D Comes From the Sun
Sunlight is the best and only natural source of vitamin D. Unlike dietary or supplementary vitamin D, when you get your ‘D’ from sunshine your body takes what it needs, and de-metabolizes any extra. That’s critical – as vitamin D experts and many health groups now advocate 1,000 to 5,000 IU of vitamin D daily – five to ten times the old recommendations. Natural sunlight is way the body was intended to make vitamin D.
Factors That Influence Production of Vitamin D in Your Skin
- Skin color, and current tan level
- Amount of time spent in the sun
- Weather conditions such as: cloud cover and pollution, ozone layer, surface reflection
- Latitude and altitude (elevation)
- Time of day
Use of Sunscreen and 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 roughly 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 at this time. Plus, when the sun goes down toward the horizon, the UVB is filtered out much more than the dangerous UVA.
This information is just beginning to permeate through the mainstream media, so let me repeat and emphasize this important point …
If you want to get out in the sun to maximize your vitamin D production, and minimize your risk of malignant melanoma, the middle of the day is the best and safest time to go. You just need to be very careful about the length of your exposure. Remember you only need enough exposure to have your skin turn the lightest shade of pink. This may only be a few minutes for some. Once you reach this point your body will not make any additional vitamin D and any additional exposure will only cause harm and damage to your skin.
Use of Sunscreen and Clothing
Keep in mind that using sunscreen while outdoors in large part nullifies your efforts to metabolize adequate amounts of vitamin D. I recommend testing your vitamin D levels to make sure you’re not deficient before resorting to sunscreen of any kind.
But, if you really need some form of sun protection because you’re outside for extended periods of time, either use light clothing to cover exposed areas, or look for safer, natural sunscreen products that contain no petrochemicals, which you can likely find in your local health food store.