Vitamin D vs. Flu
Learn more about this little vitamin with a wide reach
Vitamin D isn’t just good for us, it’s a key player in many of the body’s most basic functions. Our bodies convert a chemical within the skin to vitamin D when exposed to sun, and we can also get vitamin D from various fortified foods (like cereals and milk) and fatty fish. From helping your bones absorb calcium to cell function regulation, muscle maintenance to brain support, vitamin D is crucial to our day-to-day lives.
But did you know it’s an important factor in your immune health, too?
What is vitamin D?
Vitamin D is a fat-soluble nutrient, and is sometimes referred to as a hormone due to the myriad roles it plays within the body. Many studies on the benefits of vitamin D have been conducted because of its incredible versatility in reducing pain, supporting mental health, and even directly boosting the immune system, helping prevent disease.
No matter what function is being examined, we know vitamin D interacts with most of our cells (and we have billions of cells!). When a vitamin has such a widespread impact, we assume it must be pretty mighty if most of our body can use it. This is proven true for vitamin D, as it’s been shown to help many health conditions from depression to asthma to flu prevention. (Scientists are even examining a link between vitamin D supplementation and slowing the progression of cancer.)
With fall and winter approaching in the Midwest, we’re taking a closer look at vitamin D in relation to immune function and respiratory health, including reduced the risk of infections such as influenza and COVID-19.
Flu, respiratory infection, and COVID-19
Flu and respiratory infection
Influenza, or flu, is a contagious respiratory illness. While many people who contract the flu will recovery in a matter of days, for some, the flu can cause severe complications like pneumonia, organ or tissue inflammations, even organ failure and death. The very young and old, those with chronic medical conditions, and pregnant people are at the highest risk for flu-related illness, but even those considered traditionally “healthy” can still contract the flu virus.
Published in The BMJ in 2017, a meta-analysis of 25 randomized controlled trials found that vitamin D supplementation reduced the risk of acute respiratory tract infections (ARTIs) among participants, with those being severely vitamin D-deficient experiencing the most benefit.
The analysis states that daily or weekly vitamin D supplementation had the greatest benefit in individuals with low baseline levels of vitamin D, reducing the risk of respiratory infections by as much as 50%. This study — along with others by the National Institutes of Health, World Health Organization, and Mayo Clinic — highlighted that vitamin D may enhance the body’s natural defenses against acute respiratory infections and pathogens by modulating the immune system.
COVID-19
With the onset of the global pandemic, scientists began researching whether vitamin D, previously proven to help mitigate acute respiratory infections, could also help reduce the severity of COVID-19.
In 2021, the Journal of Clinical Endocrinology & Metabolism analyzed several studies suggesting that patients hospitalized as a result of COVID-19 had lower vitamin D levels than in control populations. Another 2021 study in The Lancet: Diabetes & Endocrinology noted the correlation between populations traditionally deficient in vitamin D were also disproportionately affected by COVID-19. The Lancet also observed that increased time spent indoors due to quarantine lockdowns raised concerns about people’s lessened levels of natural sunlight-induced vitamin D production, as well as impacting bone and muscle health.
Both the Mayo Clinic and the NIH state that while no clear connection between vitamin D levels and COVID-19 prevention currently exists, because of the vitamin’s overall benefit to body function and health, deficiency may raise your risk of contracting and suffering severe effects from the disease, including acute respiratory illnesses.
Broader implications for respiratory health
We know now that vitamin D receptors are found on many immune cells (including macrophage and dendritic cells), and that the vitamin plays a role in regulating immune responses and can impact overall health. Studies have proposed that vitamin D deficiency is one factor that leads to increased susceptibility to infections like pneumonia and bronchitis.
The first step is knowing your vitamin D levels and taking action if you are deficient. Knowing your levels will can determine supplement dosing, thus helping you more quickly achieve your optimal vitamin D levels. Testing is simple and can be done in office at Lake Pointe using our Vitamin D finger stick test by OmegaQuant. Scheduling is available online, can be added to an expanded chiropractic visit, or can be booked by calling our front desk.
The bottom line
Our main takeaway is that maintaining optimal vitamin D levels can, at the very least, reduce severity of many different illnesses including the flu and COVID-19. However, it’s important to keep in mind that strong vitamin D levels are just one of many ways to help support a healthy immune system — among them embracing a diet rich in ‘whole’ foods and veggies, getting plenty of sleep, and caring for your mental health as you continue on your health journey.