Improve gut health with this neglected behavior

People go to great lengths to improve their gut health, and for good reason. Good gut health is the key to overall health. A new study shows something many avoid has a beneficial effect on gut health.

If you talk to your dermatologist, they will likely tell you to avoid the Sun to prevent skin cancer. But the problem is, there are far reaching benefits of Sun exposure that reach beyond the skin. I covered the many benefits of exposing your skin to the Sun for gut health. You can check out one of those blogs here.

This new study shows that exposing your skin to UVB rays during the winter boosts microbial diversity. Part of this was from increased vitamin D. The effect only occurred in those who were not taking vitamin D supplements.

But there are other reasons to expose your skin to the Sun to improve gut health. Let’s look at how this may work.

sun exposure to improve gut health

How Sun exposure improves gut health

The effects of vitamin D on gut health are fairly diverse. First, vitamin D plays a role in pancreatic enzyme synthesis. As a result of vitamin D deficiency or hypopararthyroidism, many experience exocrine pancreatic insufficiency.

The vitamin D receptor is located basically everywhere, including the gut. The VDR helps regulate the immune system, how your gut responds to glucocorticoids, and regulates calcium absorption in the gut. Coupled with a high fat diet, poor vitamin D status causes poor calcium absorption and may predispose to excessive oxalate absorption.

But vitamin D isn’t the only beneficial effect of Sun exposure. There are also immune modulating benefits of UVB rays that don’t depend on vitamin D. While some effects are localized to the skin, factors generated in the skin appear to communicate with the gut.

One of these factors is bilirubin, a bile pigment generated from Sun exposure. Bilirubin is conjugated in the liver and dumped in to the gut. Bacterial transformation of bilirubin is what makes our feces brown and urine yellow.

Other factors exist as well. So it’s not surprising researchers believe that these effects are solely due to vitamin D.


If you want to improve gut health, don’t focus simply on what you’re eating. The systems in our body are integrated with one another, and circadian rhythms are critical for this. Things like exercise, when you eat, sleep, and exposure to the Sun are all important factors that can improve gut health.

This study shows that exposing your skin to the Sun is an important factor for gut health. It may seem odd that skin exposure to the Sun is important for the gut, but there is ample evidence that this is so. While most of the data up to this point was in mice, this study was in women during the winter. Thus, it provides evidence that skin exposure to the Sun is an important factor for gut health.

9 thoughts on “Improve gut health with this neglected behavior

  1. Nona says:

    Any advice on getting enough sunlight in the northeast during the winter months?

    I note that the study was done on women during the winter; presumably the sunlight struck only the women’s faces and possibly their hands. Still, I ask: it seems like quite limited skin exposure.

  2. ~Nona says:

    Dave, I just ordered the Sperti lamp. The form asked how I heard about the product. I gave your name. I hope you get a referral fee!

  3. Nona says:

    If you check out the Q&As on this product, you will learn from the very first question (and its answer) that the product does not make Vitamin D.

    These kinds of lights/lamps are used “fake” bright light. Many say that it works for them. I’d check out the various reviews before buying any one of these kinds of lights. I noticed a number of dicey reviews on the light that you referenced.

    Good luck.

  4. cincodm says:

    What you posted is just a light box, it doesn’t put out UVB. It’s more for seasonal affective disorder and setting your circadian rhythm. IMO, if you’re looking for something to help setting your master clock, just go outside or work directly in front of a window. They can be useful during winter if you are in an area where the Sun doesn’t rise until later am.

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