How the sunshine vitamin does more than give you healthy bones
Do you know your vitamin D status? Why do I ask? It’s not just for healthy teeth and bones. The sunshine vitamin also plays a major role in maintaining a healthy immune system. As we continue to struggle with the ongoing COVID-19 pandemic, it is even more important to be aware of whether you have a vitamin D deficiency because there is data to suggest that low vitamin D levels are associated with increased risk of COVID-19 infection, as well as disease severity and death.
There is a body of observational data that is being publish to support this association. I emphasize ‘association’ because observational data is not designed to show a causal relationship. Being vitamin D deficient doesn’t cause COVID-19 infection. Rather, it may be a contributing risk factor. This is why understanding how your data is derived is so important. I will be posting more information about the different types of clinical studies over at KWOK READS soon, so stay tuned. But for now, please note that observational data is just that – a focused assessment of observations. In this case, blood vitamin D levels were measured in a sample of people who were unfortunately infected with COVID-19.
Before diving into the results, let’s pause for a moment and consider the following critical thinking questions:
How did the authors define vitamin D deficiency?
How was COVID-19 infection diagnosed?
What are the demographic characteristics of the study population? More specifically, were they mostly male or female? What was the average age? What is the predominant ethnicity?
Keep these questions in mind.
A review by Wang and colleagues (2021) suggests that people who were vitamin D deficient were:
- 2.47 times more likely to die from COVID-19 infection as compared to those who were not.
- 2.18 times more likely to require hospitalization due to COVID-19 infection.
Data by Petrelli and colleagues (2021) suggest that:
- People with vitamin D levels <20 nanograms/milliliter (ng/ml) were 1.5 times more likely to become infected
- 2.6 times more likely to have severe infection
Both of these reviews confirmed COVID-19 infection via PCR testing (blood sample). PCR results tend to be more accurate than rapid testing. This is one criterion that is common between the two reviews. The study population was derived from multiple countries and the average age range was 34 to 88 years. Deficiency was defined as either <12 ng/ml (Wang et al., 2021) or <20 ng ml (Petrelli et al., 2021). The topic of defining what is considered an adequate versus deficient vitamin D level remains controversial. However, based on conventional practice, a level <20 ng/ml is considered deficient, whereas a level >20 ng/ml but <30 ng/ml is considered insufficient.
We should also consider where our study population resides. Yes, that matters. Vitamin D status is impacted by latitude. The farther away you live from the earth’s equator, you more likely you may experience vitamin D deficiency. So, I propose the question, how may this impact COVID-19 disease management? That’s a question we may or may not get an answer to.
The mechanism by which vitamin D influences the immune response remains uncertain. Vitamin D may help reduce the cytokine storm, an inflammatory response implicated in COVID-19 infection. cytokines are small proteins that are responsible for sending cellular signals. COVID-19 binds to the angiotensin‐converting enzyme 2 (ACE2) receptor to enter cells and promote infection. This reduces ACE enzyme production which contributes to promoting inflammation. On the contrary, vitamin D increases expression of ACE2.
The take home point to all this? Your vitamin D status may be another preventative measure in fighting this ongoing pandemic. I highly recommend talking with your provider to check your vitamin D levels and see if you may need supplemental support. Here's what you should know before you start a discussion with your provider:
blood vitamin D levels are not part of the routine panel of orders and needs to be ordered separately.
There are two types of vitamin D tests: Vitamin D 1,25 DIHYDROXY (CALCITRIOL) and Vitamin D 25 HYDROXY (CHOLECALCIFEROL) - also denoted as VItD25OH. These are NOT the same thing.
The appropriate measure of total body stores derived from sun exposure and dietary intake is by assessing the VitD25OH level.
The Vitamin D 1,25 DIHYDROXY (CALCITRIOL) is typically used to assess problems related to bone metabolism or parathyroid function.
OK, so now you're ready to have an informed chat with your provider. How to start? Sun exposure alone may not provide you with adequate vitamin D stores and the body's capacity to convert sunshine to vitamin D declines over time. In addition, let's face it, we can all use a dietary makeover. The standard American diet is high in salt, saturated fats, and refined sugars and deficient in vitamins, minerals, and fiber. And even if you already adhere to a healthy eating pattern, it never hurts to check to make sure that you are getting enough vitamin D. Lastly, you really want to maintain a healthy immune system, especially in dealing with an ongoing pandemic!
Please keep in mind that a vitamin isn’t just a vitamin and more is not better. Vitamin D is also a prohormone. It is a signal that helps maintain balance of calcium stores in the body. Taking vitamin D in excess can lead to dangerously high calcium levels (aka hypercalcemia). Abdominal pain, nausea, vomiting, confusion, lethargy, bone pain with a side of heart rhythm problems, anyone? No, thank you!
Vitamin D is a fat soluble nutrient. It accumulates in your fat tissues. So it's not as easily cleared from the system as a water soluble vitamin like vitamin C. Whatever vitamin C that doesn't get absorbed gets excreted in the urine (insert caveat: your kidneys are in good working condition) so toxicity is less likely.
And so, this is where I bid you adieu. Thank you so much for stopping by. I hope that you found this discussion informative and that you may feel that you can have an informative discussion with your provider about your vitamin D status. The next thing to consider which supplement to choose? There’s so many! Anyone interested in wading through some information and product overload?
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Until next time, dear Readers! Be well and be safe.
In health,
Mary
References:
Petrelli, F., Luciani, A., Perego, G., Dognini, G., Colombelli, P. L., & Ghidini, A. (2021). Therapeutic and prognostic role of vitamin D for COVID-19 infection: A systematic review and meta-analysis of 43 observational studies. The Journal of steroid biochemistry and molecular biology, 211, 105883. https://doi.org/10.1016/j.jsbmb.2021.105883
Wang, Z., Joshi, A., Leopold, K., Jackson, S., Christensen, S., Nayfeh, T., Mohammed, K., Creo, A., Tebben, P., & Kumar, S. (2021). Association of vitamin D deficiency with COVID-19 infection severity: Systematic review and meta-analysis. Clinical endocrinology, 10.1111/cen.14540. Advance online publication. https://doi.org/10.1111/cen.14540