The Elephant In The Living Room Is Still Being Ignored

As the headline says, the elephant sitting in the living room, i.e., that sunbeds are the ideal source of vitamin D-effective photons, is still being ignored. The “good news” is that more and more articles are being published by both the scientific and mainstream media recommending 15 minutes of exposure to sunlight once or twice a week instead of recommending sun avoidance. The “bad news” is none of these articles acknowledged that 15 minutes of sunlight exposure once or twice a week is not enough to attain and maintain an optimal level (150 nmol/L) of vitamin D year-round—nor was there any recommendation for using sunbeds to stimulate vitamin D.

The monthly and time-of-day data contained in the graphs and information that follows shows why 15 minutes of sunlight exposure once or twice a week cannot be relied upon to stimulate an optimal level of vitamin D.

Graph 1 on page 38 shows that it takes 28 minutes of wholebody exposure (14 minutes per side) two or three times a week at noon in sunny Tucson, Ariz. during July for the average person— defined as skin subtype 3B—to stimulate an optimal level of vitamin D. This time frame increases to 108 minutes (54 minutes per side) in January at noon. Compare this to a typical sunbed, which only takes an average of 8 minutes (4- to 12-minute range) to stimulate the same amount. Therefore, a sunbed has 7.5 times more power to stimulate the production of vitamin D than the monthly average (60 minutes; 30 minutes per side) and 3.5 times more power than July sunlight (28 minutes; 4 minutes per side). When you consider that a sunbed emits the same amount of vitamin D-effective photons 24/7, you can see why patronizing an indoor tanning salon year-round is the ideal way for the public to attain and maintain an optimal vitamin D level.

Note: The red line shows the “relative power” of each month to produce the same optimal level of vitamin D as the “peak” month of July, and the bars show the number of minutes that it will take each month to stimulate that amount. As you can see, exposure times are approximately 30 minutes (15 minutes per side) in June, July and August; approximately 40 minutes (20 minutes per side) in May and September; and approximately 60 minutes (30 minutes per side) in April and October. The remaining months of January, February, March, November and December require unrealistically longer times.

Graph 2 on page 38 shows how the specific time of day—between 8 a.m. and 4 p.m.—affects sunlight’s ability to stimulate the cutaneous production of vitamin D during July. As mentioned before, it takes 28 minutes (14 minutes per side) two or three times per week for an average person to stimulate the cutaneous production of an optimal level of vitamin D at noon—increasing to 167 minutes at 8 a.m. However, since it only takes an average of 8 minutes (4- to 12-minute range) for a sunbed to stimulate the same optimal level of vitamin D, it can be seen that a sunbed has eight times more power than the daily sunlight average (64 minutes) and 3.5 times more power than the noon sun.

Note: The red line shows the “relative power” of each half hour to produce the same optimal level of vitamin D as the “peak” time of noon, and the bars show the number of minutes it will take to stimulate that amount. As you can see, exposure times of approximately 30 minutes (15 minutes per side) between 11 a.m. and 1 p.m. will be adequate and approximately 40 minutes (20 minutes per side) will be required from 10 a.m. to 11 a.m. and from 1 p.m. to 2 p.m. Please note that unrealistically longer times are required before 10 a.m. and after 2 p.m.

Those of you who are mathematically inclined can use the “relative power” numbers to calculate the time it will take to stimulate an optimal level of vitamin D for different months and at different times of the day. You will find that it takes approximately 

Click here for full-size graph

60 minutes (30 minutes per side) at 10 a.m. in May and September; 
80 minutes (40 minutes per side) at 10 a.m. in April and October; and 
106 minutes (53 minutes per side) at 10 a.m. in March and November.

This shows why the dermatology community’s recommendation to avoid sunlight between 10 a.m. and 2 p.m.—with no consideration of the daily/monthly variation in the number of vitamin D-effective photons available—makes absolutely no sense. For example, it takes approximately 240 minutes (4 hours) at 10 a.m. and more than 600 minutes (10 hours) at 8 a.m. in January and December to stimulate an optimal level of vitamin D.

The bottom line is that it takes far longer than 15 minutes to stimulate a biologically optimal level of vitamin D for much of the year, even in sunny Tucson, Ariz. Therefore, this recommendation should be ignored because—as shown by the graphs above—the number of vitamin Deffective photons varies according to the month of the year and time of day and these variations must be taken into consideration in order to make valid public health recommendations.

This article helps to explain why, in study after study, it was found that more than 50 percent of the American public has suboptimal vitamin D levels, even when the unrealistically low target level of 50 nmol/L is used and more than 95 percent have suboptimal levels when the target level of 150 nmol/L is used.

Think about this question: If 15 minutes of daily sunlight exposure is adequate, why does the majority of the public show suboptimal levels of vitamin D in study after study?

Ubiquitous Vitamin D

A recent article in a medical journal stated that, because so many diseases like cancer, coronary heart disease, diabetes, multiple sclerosis, obesity, osteoporosis, etc. are mediated by vitamin D, it is impossible to get a valid measure of the health and welfare of the American public unless and until the pandemic of insufficient vitamin D levels is resolved.

Unfortunately the author only recommended the use of vitamin D supplementation to resolve the problem. As you would expect—given the money involved—this recommendation will have the support of the big pharmaceutical companies that stand to profit from selling over-the-counter and prescription vitamin D supplements and that of the medical community, which will profit from controlling access to these prescriptions.

This is all in spite of the fact that both groups know, or reasonably should know, that there is a risk of toxicity with vitamin D supplementation; also, vitamin D supplements aren’t as biologically effective as the natural form produced by the skin in response to UVR exposure.

First of all, the indoor tanning industry is prohibited by FDA and FTC from telling the American public that sunbeds are the safest, most-convenient, controlled and cost-effective year-round source of vitamin D-effective photons.

Next, it is unrealistic to expect that the pharmaceutical companies (which will profit from vitamin D supplements) or the medical community (which will profit from controlling access to vitamin D supplements) or the mainstream media (which derives significant revenue from sunscreen and vitamin D supplement advertising) will tell the public the truth about this important issue.

Therefore, it is our opinion that the Internet must be used creatively (blogs, Web sites, etc.) to get the information about the elephant sitting in the living room, i.e., that indoor tanning salons are the ideal year-round and controlled source of vitamin D-effective photons, disseminated to the public.

Patricia E. Reykdal owns and operates four tanning salons in Tucson, Ariz. Her husband, Donald L. Smith, is director of research of the Non-Ionizing Radiation Research Institute. Together, they have written more than 250 articles promoting sensible, moderate and responsible exposure to ultraviolet radiation. You can e-mail comments or questions to reyksmith@aol.com.