We are at the height of Summer, and it is prime time to take advantage of the Sun, and its incredible ability to give us the “sunshine” vitamin. Actually, it’s an intricate, and miraculous interplay of Helios’ UV rays with our largest organ; the skin. The team behind converting sunshine into vitamin D also includes cholesterol, the liver, kidneys, and cells.
What Does Vitamin D Do?
Here’s a partial list:
- Bone health ~ prevents osteoporosis, osteomalacia, and rickets
- Auto-immune diseases ~ decreases risk of rheumatoid arthritis, multiple sclerosis, and Type I diabetes
- Mental health ~ improves SAD (Seasonal Affective Disorder), depression, and for the females, PMS
- Cancer prevention ~ shown to decrease risk of breast, prostate, and colon cancers
Vitamin D Deficiency Symptoms
And here’s a list of symptoms to look out for that signals deficiency:
- Osteoporosis and Osteomalacia
- 17 varieties of Cancer (including breast, prostate and colon)
- Heart disease
- High blood pressure
- Metabolic Syndrome and Diabetes
- Autoimmune diseases
- Multiple sclerosis
- Rheumatoid arthritis
- Infertility and PMS
- Parkinson’s Disease
- Depression and Seasonal Affective Disorder
- Alzheimer’s Disease
- Chronic fatigue syndrome
- Chronic Pain
- Periodontal disease
Yet, in spite of irrefutable evidence that we need sunlight, lack of vitamin D has reached epidemic proportions in the 21st century, brought on by a combination of:
- Sun phobia. For decades, the people who make suntan lotions have scared the living daylights out of us regarding sun exposure and skin cancers. As a result, babies and adults slather suntan lotions on which prevent the skin from absorbing the needed UVB radiation to produce vitamin D. Please note that sun-protection is important, but in order to get precious vitamin D from the Sun, we need to expose unprotected skin for a short time to absorb the UVB rays.
- Long hours spent in-doors in front of computers, TV screens, and game consoles.
- Poor diets lacking in vitamin D, and an increase in the incidence of digestive problems. This includes IBS (Irritable Bowel Syndrome) or gastric reflux, both of which prevent optimal vitamin D absorption through food or supplementation.
Hey, and if you engage in all three vitamin D-depleting activities, then chances are you too may be deficient in D.
A Little Sunshine Science
Sunlight is composed of electromagnetic radiation of varying lengths, including ultraviolet or UV radiations: UVA, UVB, and UVC. The last is completely destroyed by the atmosphere, so we are only affected by UVA and UVB, which act differently on us. UVA is the one which gives us wrinkles, and in very high doses, can lead to cancerous melanomas. UVB is what causes skin to burn if over exposed to sunlight, and may lead to non-melamona skin cancer over time. However, UVB is also what stimulates the skin to produce our beloved and vital vitamin D.
The most important point to keep in mind is that there is a huge difference between safely exposing yourself to acquire healthy levels of vitamin D, and over-tanning to the point of scorching your skin and creating risk factors for skin cancers.
The amount of sun sourced vitamin D you get depends on your location and time of year. If you live in mid-latitudes (35°–50º), cities including: NY, SF, Boston, there is no UVB to be had during November through February so supplementation would be a good idea. (Check in next week for Part II as I discuss vitamin D in foods, supplementation, and the real deal behind skin cancer and sunbathing.) For the rest of the year, and especially during the Summer, get bare and get safe sun.
How Much Sun Exposure Is Safe?
Here is “The Horlick Formula for Safe Sun” created by Dr. Michael Horlick, a renowned vitamin D researcher, and author of The UV Advantage.
Expose 25 percent of your body’s surface area to 25 percent of *1MED two to three times per week, without sunscreen, during all times of the year when UVB rays are available where you live. 1MED just means one minimal erythemal dose, which in plain English is the time it takes for you to get a mild sunburn, without sunscreen.
Wait, don’t be confused! It’s rather simple when you do some easy math and locate your coordinates.
So, here’s an example on how you do it according to Dr. Horlick’s Formula for Safe Sun:
- Go outside in your shorts or bathing suite (ideally before 10 AM or after 2 PM), without sunscreen, and see how long it takes for your skin to get mildly pink. This is your 1MED.
- After that, either get back indoors, or put on a full-spectrum sunscreen.
- Multiply your personal 1MED by 25%. For example, If it took 15 minutes for you to turn pink, or 1MED, 15 multiplied by .25, gives you approximately 4 minutes.
- Now get out and enjoy the sun with 25% of your body exposed (this means expose your face, hands, and arms, OR arms and legs) for about 4 minutes, two to three times per week, when UVB rays are available where you live.
(After the desired exposure time to get your vitamin D, use a full-spectrum suntan lotion if you want to stay out longer.)
According to Dr. Horlick, this method will provide you with approximately 1,000 IU of vitamin D. The more skin you expose, the more vitamin D you will make. Keep in mind that although 1,000 IU is a good amount, individual needs differ greatly and the optimal amount you require per day depends on your existing vitamin status, and also on the amount of vitamin D in your diet.
I highly recommend that you get Dr. Horlick’s book, The UV Advantage. It’s easy to read, and includes valuable information on: how vitamin D prevents diseases, the truth about suntan lotions and skin cancer, how to get adequate vitamin D through supplements or indoor tanning. Plus it has a super-nifty chart on when and where to get the best exposure of UVB.
And of course, visit me next week as I share more amazing vitamin D facts, how to test your very own vitamin D level, and a few delicious recipes with vitamin D-rich foods.
Your ally in health,
Horlick, Michael. The UV Advantage. New York: ibooks, Inc. 2003.
Tavera-Mendoza, Luz., White, John H. Cell Defenses and the Sunshine Vitamin. Scientific America, p. 62 – 72, November 2007.
Wehr, E., Pilz, S., Boehm, B. O., März, W. and Obermayer-Pietsch, B. (2010), Association of vitamin D status with serum androgen levels in men. Clinical Endocrinology, 73: 243–248. doi: 10.1111/j.1365-2265.2009.03777.x