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A Vitamin D-lemma: Sunscreen vs. Healthy Sun Exposure


A Vitamin D-lemma: Sunscreen vs. Healthy Sun Exposure

The Dirt:

Our bodies need vitamin D to function properly and to maintain a healthy immune system. The most available source is sunlight. However, sunlight can also damage our skin. So how can we boost our immune system and keep our bodies strong by getting our much-needed vitamin D while also practicing safe sun protection? Let's take a look!

Vitamin D is an especially important nutrient right now, as we all have a heightened awareness about our immune health to battle COVID-19. In addition to aiding in cellular function, bone growth & strengthening, Vitamin D is also a crucial player in fortifying our immune system.

Moreover, according to a new study out of Northwestern University, researchers found a strong correlation to Vitamin D deficiency and COVID-19 mortality. According to data derived from 10 different countries, “the researchers noted that patients from countries with high COVID-19 mortality rates, such as Italy, Spain and the UK, had lower levels of vitamin D compared to patients in countries that were not as severely affected.”

The Benefits of Vitamin D

Did you know our kidneys can produce 90% of our daily dose of vitamin D? Our bodies are able to process vitamin D through receptors in our skin cells. We are able to process up to 90% of that vitamin D we need through this exposure to the sun. However, there are limited foods that are high naturally in vitamin D to make up that 10% that we are unable to process through the sun. Most dermatologist and endocrinologist alike will recommend vitamin D be taken as a supplement to ensure that your daily dose is reached.

Vitamin D controls our blood calcium levels and helps strengthen our immune system. It promotes healthy bones, muscle function, cardiovascular function, brain development, and support for our respiratory system. Despite its name, vitamin D is actually a prohormone, not a vitamin. When the body receives vitamin D, it turns it into a hormone, sometimes called “activated vitamin D”, or “calcitriol”.

sunscreen, A Vitamin D-lemma: Sunscreen vs. Healthy Sun Exposure

Source: www.globalhealingcenter.com

Though vitamin D is also found in several foods, the prohormone is most readily available through direct exposure to UV rays. Through a series of chemical processes, the skin turns sunlight into cholecalciferol, which the liver then converts into vitamin D. In short, we can synthesize vitamin D through sunlight hitting our skin, making us more like plants than we thought!

Surprisingly, vitamin D can actually serve as a protectant for the skin from UVB rays. As Dr. Gominak explains, based on her extensive studies:

“Vitamin D…goes into the cells nucleus to repair the DNA damage caused by the UVB light, thus preventing skin cancer. This means that there was already a natural process that protected us from skin cancer caused by sun exposure.”

So I can get my recommended dosage of vitamin D from the sun in a healthy way that can actually benefit my body? Sounds like I’ll be getting a tan this summer!

Don’t Forget the Sunscreen

But about that tan…what about the motherly warnings against sunspots, wrinkly skin and increased chances of cancer development? Not to worry, I am fully equipped to combat those with my army of sunscreen. I have my convenient spray for quick re-applications, my face stick to make sure my nose and ears are fully concealed, and my lightly-tinted body lotion to give me that extra glow. Very responsible of me…my mom would be proud! Or would she?

A study conducted in January 2020 on the effects of sunscreen application on plasma concentration of sunscreen active ingredients revealed similar findings to last years’ research. The results showed that four active ingredients in sunscreen: oxybenzone, octinoxate, homosalate, and octisalate, are all systemically absorbed into the bloodstream when applied to skin. While this study still lacks sufficient evidence to prove true health implications, it has surpassed the plasma concentration threshold set by the FDA, which was the marker for the need for further safety studies.

In short, this study’s findings will pave the way for future clinical studies that will help make more concrete results impactful at a formal, regulatory level. Dr. Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research, states that: “this finding calls for further testing to determine the safety and efficacy of systemic exposure of sunscreen ingredients.” Dr. Woodcock continues to stress that, “whether this is dangerous is still not known.”

The FDA addressed the lack of regulatory safety testing and efficacy for the first time in sunscreens in 2019. Until then, they had not tested sunscreens for how they absorb into the bloodstream, as the formulations were designed to sit on the skin as a topical shield from UVB rays. This 2020 study will surely lead to more clinical studies, and hopefully, more significant findings that will help consumers decide on what sunscreen is best for them, and help our regulatory bodies enforce safety precautions.

Studies published in The Journal of the American Medical Association evaluated the systemic absorption of active ingredients in four commercially available sunscreens. In this pilot study, all four active ingredients tested were absorbed into the bloodstream!  And while not all ingredients absorbed through the skin are hazardous and our bodies are able to process most toxicants, the study calls for further research and testing to determine the safety of ingredients for repeated use.

While the testing continues, the FDA has proposed a rule in 2019, that requires sunscreens to be regulated in the same way as drugs. This was put in place to bring all over-the-counter sunscreens up to date with the latest scientific standards, and ensure they are generally recognized as safe and effective (GRASE). While testing and approvals are still in the works as of May 2020, here is a guide to help you navigate what is safe for use!

sunscreen, A Vitamin D-lemma: Sunscreen vs. Healthy Sun Exposure

Here are the proposed regulations outside of just ingredient-testing for sunscreens — this includes SPF levels, label requirements and dosage recommendations.

Which Sunscreens are Best?

So what sunscreens can I use, and what should I look for? Two active ingredients already considered GRASE are zinc-oxide and titanium dioxide; if you see these on your label, you can rest assured you are in the clear. On the other hand, PABA and trolamine salicylate have been deemed unsafe for use, so avoid sunscreens containing these ingredients. Most other chemicals are still under investigation by the FDA and have insufficient data to make a conclusive safety determination, here is a chart that illustrates how to best read your sunscreen label:

sunscreen, A Vitamin D-lemma: Sunscreen vs. Healthy Sun Exposure

If you’re curious about other ways to protect your skin from sun damage and pollutants, check out our post on Skin: Your Body’s Largest Organ here. And if you’re wondering more about vitamin D and its effect on our health, stay tuned for more from Dirt to Dinner on this topic!

The Bottom Line:

Be sure to protect your skin with sunscreen, but stay informed by reading the ingredient labels to understand what you’re putting on your skin. Talk to your doctor about your recommended sunlight exposure to optimize your vitamin D levels and supplement with foods rich in vitamin D. Have a happy and safe summer!

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