This week our vibrant summer series continues with another aspect of your health worthy of soaking in: vitamin D.
We sat down with Sheena Batura, our very own Registered Dietitian, to explain the significance of this vital vitamin. Sheena has a broad range of experience in the nutrition world, providing nutrition education and medical nutrition therapy to help patients with topics ranging from gastrointestinal issues, diabetes education, cardiac rehabilitation, and weight management. She also lends her expertise to Everlywell by breaking down insights and answering your questions in our post-results webinars for Heart Health, HbA1c, Metabolism, Testosterone, Food Sensitivity, Vitamin D, and Vitamin B9 tests.
In this article, you’ll learn about vitamin D deficiencies, the importance of testing, and what summer activities or lifestyle changes you can take to maintain your vitamin D levels beyond the summer.
Though vitamin D is primarily known for its role in bone health, which is essential to maintain throughout one’s lifespan, vitamin D is an emerging area of interest for its potentially protective role with regard to a number of health conditions.
Vitamin D may have a protective role against cancer, diabetes, heart disease; neurological conditions such as Alzheimer’s disease, Parkinson’s disease; mental health disorders; and autoimmune disorders such as rheumatoid arthritis and multiple sclerosis.
Vitamin D’s role in immunomodulation—and in particular past research regarding vitamin D and viral respiratory illnesses such as acute respiratory infections, pneumonia, and influenza—has sparked recent interest regarding vitamin D and COVID-19. Researchers are investigating if maintaining optimal vitamin D status is protective against COVID-19, and if optimal vitamin D levels can reduce the severity of COVID-19 symptoms or decrease the replication of the SARS-CoV-2 virus in the upper respiratory tract—potentially making it less infectious.
A cross-sectional analysis found that COVID-19 mortality was inversely associated with vitamin D status in different countries in Europe, which the authors suggested may also be related to geographic latitude. Another analysis conducted by UK Biobank did not support a potential link between vitamin D levels and COVID-19 infections, suggesting the relationship between vitamin D levels and COVID-19 needs further examination. Many other studies investigating similar research questions are underway or are in pre-print, meaning they await peer review.
Though the preliminary findings overall appear promising, it’s important to remember that correlation doesn’t necessarily imply causation. A number of independent variables can influence a person’s risk for COVID-19—socioeconomics, demographics, pre-existing illnesses, and BMI to name a few. This makes it difficult to suggest low levels of vitamin D levels are a significant risk factor, or that vitamin D supplementation is protective against COVID-19 or its severity.
Long-term studies (to evaluate the seasonality of vitamin D levels), and randomized controlled trials, will be required to support that supplementation for this vitamin is protective against infection from SARS-CoV-2—the virus that causes COVID-19. Still, since vitamin D does play an important role in so many different aspects of our health, one can only argue for maintaining adequate vitamin D levels—starting with regular sunlight exposure and vitamin D food sources.
Though seasonal variation for vitamin D is expected and is commonly lower in the winter months, lower levels in summer are possible. A major cause of vitamin D deficiency in healthy people is inadequate exposure to sunlight. If you work all day indoors and aren’t able to get sunlight exposure, or prefer to avoid the extreme heat and stay inside, these may be a few reasons one may expect lower levels of vitamin D during the summer months. Even a short 15-20 minute session in the sun between 10:00 am - 3:00 pm a few times per week can help.
High SPF sunscreen may also inhibit absorption; however, if you are anticipating being out in the sun for a prolonged period of time, the American Academy of Dermatology does recommend wearing broad-spectrum sunblock to protect against skin cancer.
If your diet is void of food sources of vitamin D like seafood, fortified foods like milk or UVB-treated mushrooms, or you’re in a high-risk group for deficiency such as older adults, those with a history of fat malabsorptive conditions, for example, can also increase your likelihood for having lower levels of vitamin D. Skin tone, pollution, and living at a high latitude may also influence vitamin D levels.
First, vitamin D deficiency (or hypovitaminosis D) isn’t always obvious or paired with symptoms. You may have lower levels of vitamin D and not even know it. But if symptoms are present, most often they manifest as bone pain, muscle aches, and muscle weakness.
The most common symptoms of vitamin D toxicity, otherwise known as hypervitaminosis D, are confusion, recurrent vomiting, abdominal pain, polyuria (or excessive urination), polydipsia (or excessive thirst), and dehydration. In healthy individuals, this is often the result of prolonged use of megadoses of vitamin D supplements—so large doses over the course of several months.
Vitamin D toxicity is not known to be caused by excessive sunlight exposure, or through food. This is often paired with vitamin D levels in the blood exceeding 150ng/mL. Over time, having higher levels of vitamin D can lead to higher levels of calcium in the blood, kidney stones, and potentially kidney damage, which is why it’s not advised to take high concentrations of this vitamin without medical supervision.
If you check your vitamin D levels and find that you have lower levels of vitamin D, you’ll likely be advised to retest roughly 3 months after your healthcare provider has recommended an appropriate dosage in order to evaluate its effectiveness. Similarly, if your vitamin D level is too high, they may advise discontinuing the use of supplements or decreasing the dose and retesting following modifying your dose.
At this time, universal screening for vitamin D in the general population isn’t generally advised by any major society or association within the United States. However, the Endocrine Society suggests that those who are at risk for vitamin D deficiency may benefit from screenings, like older adults and those with fat malabsorptive conditions.
Participating in regular physical activity in the great outdoors can not only help you get regular UVB exposure, but exercise also supports your overall health—both mental and physical.
Taking a break outside during the workday may also help you improve your levels. Throwing more seafood on the grill, making sure your plant-based milk you use in your smoothie is fortified with vitamin D, or adding UVB-treated mushrooms to kabobs, are just a few great ways to get more sunlight exposure and incorporate more vitamin D-rich foods into your diet during the summertime.
Inspired to check your vitamin D levels? This week only, save 25% on your entire order when you purchase a Vitamin D Test. If you’re looking for ways to check in with your health this summer, we offer 30+ at-home tests that provide insights in days!
Miss our last post featuring Dr. Charlene Brown sharing her expertise on thyroid health and tips to stay safe during a COVID-19 summer? You can catch up on her insights here. Until next week, stay motivated and continue to prioritize your health!