Are there significant health benefits of sun exposure?
Why yes, yes there are. “Oh, Mr. Sun, Sun, Mr. Golden Sun, please shine down on me!” This classic nursery song was a popular ditty when I was teaching school. It’s a classic melody that has been passed from generation to generation. As an integrative and functional nutrition practitioner, this tune has a completely different meaning to me now. Why do we want the sun to shine down on us? There are many health benefits to sun exposure.
Health Benefits of the Sun Beyond Vitamin D
UV Rays Can Actually Help with Disease and Cancer Prevention
The sun is often touted for its role in vitamin D synthesis. This is true. It is important to highlight this vitamin is a vital nutrient in promoting health and preventing disease. However, vitamin D is not the only benefit of the sun. The sun also serves to nurture the body through ultraviolet radiation. Yes, the sun’s ultraviolet rays are not always bad for you. Often, ultraviolet radiation is discussed as the source of skin burns and cancers. What if I were to tell you that sunlight in moderation could be the source of disease prevention? A 20-year study noted that women who limited sun exposure were twice as likely to die from any disease (1). A 2021 study (2) highlighted the benefits of safe sunlight exposure, specifically for individuals with autoimmune conditions. The researchers noted that the anti-inflammatory benefits of sunlight were independent of vitamin D synthesis. The ultraviolet benefits impact various cells and pathways that may slow the development of disease or reduce risk of developing disease. Exposure to UVA and UVB radiation enhances the cells that remove the problematic self-reactive T cells. This serves to prevent autoimmune conditions.
Rather than focus on the cancers that sun exposure causes, it’s important to review the cancer types that it may prevent. Colorectal cancer has been a focus of this research. A recent study noted the inverse relationship between sun exposure, specifically UVB, and incidence of this type of cancer. The study noted significant findings in participants older than 45. For those with a personal or family history of these diseases, safe sunlight exposure might serve as an additional preventative treatment (3).
Vitamin D Supplementation and Sun Exposure Go Hand-In-Hand
In fact, a 2020 study noted that lack of sun exposure is becoming a public health issue. Alfredsson et al. (4) reviewed research from the previous decade noting that vitamin D supplementation does not have the same effect as sunlight exposure in mitigating autoimmune conditions such as multiple sclerosis and type 1 diabetes, cardiovascular disease, certain cancers, high blood pressure and Alzheimer’s disease. The scientists reviewed a variety of research which found interesting results indicating that vitamin D supplementation does not serve to protect the human body as a single nutrient. It most likely needs the synergistic effect of UV radiation. Regarding multiple sclerosis, studies show past sun exposure as a child reduces MS risk by 50%. Studies which focus on type 1 diabetes are not conclusive. However, there is some evidence that suggests lack of sun exposure during gestation or infancy may serve as an environmental trigger for this disease. Research related to cardiovascular disease and hypertension demonstrates that sunlight exposure reduces risk of these health issues (5).
The evidence does not indicate that UV exposure is enough to protect the body. Vitamin D continues to aid in this process. It appears that vitamin D through sunlight is ideal, however, this source is not always readily available or readily absorbed. It is important to request a vitamin D level to assess your current status. With this information, the focus should be to consume vitamin D through diet and sunlight.
Supplementing Vitamin D
According to the National Institute of Health, the preferred serum level of vitamin D for adults is greater than 20 ng/ML. In functional medicine, the recommended serum range is between 35-60 ng/ML. Vitamin D benefits from its fat-soluble counterparts, vitamins A and K. These three vitamins work together to improve absorption and promote balance. This is important to remember when selecting a vitamin D supplement. With diet, it is easier to make sure to consume all the fat-soluble vitamins and benefit from the synergistic response. Most of the time, a vitamin D rich food source will also include vitamin A and/or vitamin K. See below for a list of vitamin D dietary sources. Meeting nutrient needs through nature such as food and sunlight is the best way to accommodate the needs of the body. Supplementation can be utilized when there is confirmation of deficiency or inadequate levels related to disease states.
Vitamin D Dietary Sources
- Cod liver oil
- Salmon
- White mushrooms
- Sardines
- Whole egg
- Tuna
- Chicken
- Beef
- Broccoli
- Carrot
- Almond
- Lentils
- Sunflower seeds
- Edamame
- Fortified foods such as milk or cereals
How can you reap the health benefits of safe sun exposure?
What does this mean for you? Safely embrace the sunshine of the summer months especially if you live on the east coast or in the pacific northwest. Dermatologists recommend short periods (5-30 minutes) of sunblock free exposure to prevent sun damage, skin cancers and other potential health issues. Also, check for UV index to make sure you avoid sunburn and accessorize appropriately to protect the body including the eyes.
The lesson from this dietitian educator is: Take advantage of the summer months and its sunshine through safe practices. And, add vitamin D food sources to your weekend barbeques and weeknight dinners. If you need help with Vitamin D testing or a nutrient deficiency, reach out or learn more on my Services page.
Sources
- DOI: 10.1111/joim.12496
- https://doi.org/10.1016/j.jsbmb.2021.105957
- DOI: 10.1186/s12889-021-11089-w
- doi: 10.3390/ijerph17145014
- doi: 10.1039/C6PP00336B.
