Vitamin D + Viruses

I hope you are all staying safe during these interesting times and getting outside to breathe in some fresh air and to soak in some vitamin D from the sun!

In this current pandemic, medical experts are trying to piece together the puzzle and provide a roadmap to treating this infection.  New data and research are beginning to show some of this picture; however, many puzzle pieces are still missing, and no one seems to know how many puzzle pieces are even in the box.  Chances are it will take time to really understand the entirely of this infection. 

The impact of vitamin D might be one puzzle piece to consider. In 2017 I wrote a blog post highlighting the benefits of Vitamin D: which you can read here: More recently, some major publications are rolling out research showing the direct correlation with high vitamin D levels and improved survival rates among patients with COVID-19 and other viral illnesses.

The Vast Roles of Vitamin D

Vitamin D is produced in your body through a chemical reaction when your skin is exposed to sunlight (UVB rays).  Vitamin D is transported to the liver and then kidneys, where it is converted to an active hormone. This increases calcium transport to the bones to keep our musculoskeletal system strong.

Frontiers | Immune Response Modulation by Vitamin D: Role ...

Vitamin D can also reduce risk for infection through several mechanisms. “Vitamin D can lower viral replication rates and reduce concentrations of pro-inflammatory cytokines that produce the inflammation that injures the lining of the lungs, leading to pneumonia, as well as increasing concentrations of anti-inflammatory cytokines” (Grant, et al., 2020).

Vitamin D Deficiency & Poor Health Outcomes

Vitamin D deficiency has been found to contribute to acute respiratory distress syndrome (ARDS), a lung issue resembling what COVID-19 patients have experience. Respiratory symptoms resulting in decreased oxygenation (hypoxia) and altered lung function, can linger weeks to months post infection.

Furthermore, low vitamin D levels are shown to be pro-inflammatory. People at risk for lower vitamin D levels and higher severity of illness are those whom are elderly, have a chronic illness, heart disease or have metabolic syndrome – obesity, diabetes and insulin resistance.

What the Research Shows

A recent study by Grant, et. al. found 86% of all COVID-19 cases among patients with normal vitamin D levels were mild, while 73% of cases among patients with noted vitamin D deficiency were severe or critical. This research also noted that Northern Hemisphere countries have seen increased cases of infection compared to countries south of the equator.  It is worth considering this outbreak started during winter months when concentrations of vitamin D are lowest because days are shorter, and communities are spending more time inside. Although there are many other factors that could contribute to the discrepancy in cases, it might also be worth considering.


Does this Impact You?

As an integrative health provider, I have checked vitamin D levels with hundreds of my patients. From my clinical experience, children to elderly adults in Iowa (and the Midwest) are often deficient in vitamin D. Our sun exposure intensity and duration are not adequate to provide our bodies with the necessary nutrients to support a healthy immune system.

My patient’s vitamin D levels are 28 ng/mL on average. Western Medicine says 30-100 ng/mL is “normal”, but most integrative practitioners have their patients aim to reach levels on the higher end of the scale, around 60-80 ng/ml. Grant, et. al., suggests people at risk of influenza and/or COVID-19 should be taking 10,000 IU/d of vitamin D3 for a few weeks to rapidly raise 25(OH)D concentrations, followed by 5000 IU/d.

In my practice, I prescribe these doses commonly to my patients without adverse effects noted. As always, this is not intended to replace personal medical advice. Ask your provider to order your vitamin D level to see whether or not you are deficient and supplement accordingly.

At my clinic we supplement vitamin D in a variety of ways including injections, capsules, tablets and liquids finding the best route for each individual.  An injection can boost vitamin D levels immediately and traditional supplements (capsules, liquids, etc.) can help to maintain levels.

This is definitely a challenging time and while it takes time for all this brand-new data and research to be reviewed, it is still important to take a proactive approach to strengthening your immune system.

In health,

Stephanie Grutz, ARNP, FNP-C

Please Check out the Following References for more Information:

Glicio, El James, Vitamin D Level of Mild and Severe Elderly Cases of COVID-19: A Preliminary Report (May 5, 2020). Available at SSRN:

Grant, W. B., Lahore, H., Mcdonnell, S. L., Baggerly, C. A., French, C. B., Aliano, J. L., & Bhattoa, H. P. (2020). Evidence That Vitamin D Supplementation Could Reduce Risk of Influenza and COVID-19 Infections and Deaths. Nutrients. doi: 10.20944/preprints202003.0235.v2

Laird, E., Rhodes, J., & Kenny, R. A. (2020). Vitamin D and Inflammation: Potential Implications for Severity of Covid-19. Irish Medical Journal113(5), 81–81. Retrieved from

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