No. That is probably the answer you were expecting if you are asking a dermatologist, but here are some of the reasons why.
Surprisingly, epidemiological data shows that sunscreen users have higher vitamin D levels than non-users. How could this be? It is true that diligent use of sunscreen can decrease vitamin D production. However, the effectiveness of sunscreen and one major determinant of the “SPF” rating is the thickness in which it is applied. The universally recommended amount for thorough, consistent application is 1mg/cm2, or approximately 7 – 8 tsp to adequately cover an average body. On average, people only apply ¼ of this thickness during sunscreen application. Other factors that decrease efficacy are not applying at least 20 minutes prior to sun exposure and remembering to reapply approximately every 90 minutes. Therefore, it is theorized that sunscreen users may be out more often and out in the sun longer than non-users, believing they are more protected from UV rays.
Whether you are considering improving your vitamin D levels from sun exposure or from oral supplementation, why does it really matter anyways? To be honest, the importance is quite debatable. For decades, it was thought that two of the most important benefits of vitamin D were improved cardiac and bone health. Therefore, physicians routinely recommended supplements to their patients. In 2011, a landmark study from the Institute of Medicine found that vitamin D did not provide the cardiac or other serious disease benefits once attributed to vitamin D. Thereafter, vitamin D supplements have been suggested on more a more moderate scale and more limited to patients who have levels that are considered deficient.
So what about osteoporosis and bone health? To answer this question, a large, randomized, long-term study was performed to evaluate vitamin D’s benefits further. The results of this five-and-a-half-year federally funded clinical trial with over 26,000 subjects were unexpected. As published in the New England Journal of Medicine, the study concluded that not only do vitamin D supplements have no significant effect on common diseases, but they also do not prevent bone fractures. Therefore, many medical providers and several medical institutes have stopped recommending routine screening of vitamin D levels altogether. While the Institute of Medicine still recommends a daily intake of approximately 600 to 800 IU daily, people who eat a balanced diet are already ingesting this amount with their food intake. For people who do not consume vitamin D rich foods, such as fish, eggs, or milk, it is reasonable to consider taking an oral vitamin D supplement to close the gap.
To get back to the original question, should you skip sunscreen sometimes to improve your vitamin D levels? No. Vitamin D does not appear to have any appreciable effects on health. But UV radiation from sun exposure certainly does. Therefore, the dangers of sun exposure far outweigh the benefits. And now we have evidence to prove it, even from outside the perspective of a dermatologist.