Can Vitamin D Supplements Save Us from COVID?
Correlations Between Vitamin D Supplementation and COVID-19 Survival
Background
As the COVID-19 pandemic continues to grip the lives of many, it is easy to lose sight of another epidemic that is just as real, though not as visible. The epidemic of vitamin D deficiency affects nearly half of all Americans, and it gets worse during the winter months when there is less sunshine. Natural vitamin D (also known as cholecalciferol) does not actually come from the sun — it is simply the ultraviolet rays from the sun that trigger a reaction in the epidermis which results in vitamin D production. Vitamin D can also be dietary, but the typical diet does not contain nearly enough of this important vitamin.
Vitamin D has a well-researched role in skeletal calcium balance, promoting bone density. Deficiency is often associated with greater rates of osteoporosis and bone fracture. Vitamin D is converted to calcifediol in the liver, which binds to the vitamin D receptor (VDR) in target cells. The VDR then functions as a transcription factor, affecting gene expression of proteins including those involved in calcium uptake. Importantly, the VDRs also have a role in the immune system, and they are found in monocytes and activated T and B cells. Based on these roles of vitamin D, it is especially important for elderly individuals to avoid vitamin D deficiency. However, vitamin D supplements remain a point of contention, as studies disagree on whether there is sufficient evidence of their benefits to recommend supplementation.
When COVID-19 arose during the winter months, researchers were quick to draw a potential association with vitamin D. Could the reduced sunlight of the winter lead to increased vitamin D deficiency, thus contributing to greater spread and severity of COVID? The researchers in this study decided to focus on a more pressing aspect of this question: can vitamin D supplements increase survival rates of elderly COVID patients in the hospital?
Summary
This study focused on patients who had already been diagnosed with COVID-19 and were in the hospital. The average age was 88 with a standard deviation of 5 years. They were divided into three groups, though it is important to note that these groups were not randomly assigned because the groups were based on activity prior to the beginning of the study. Group 1 patients had been taking vitamin D supplements for one year prior to the COVID diagnosis. Group 2 patients were only given supplements upon diagnosis. Group 3 never had any vitamin D supplementation. The researchers were primarily investigating if either of these methods of vitamin D supplementation could increase survival rates after 14 days in the hospital. It was found that there was a significant difference in survival rate between Group 1 (93.1%, n=29) and Group 3 (68.7%, n=32) with p=0.02. The low p value indicates that it is very unlikely this difference is due to random chance. There was no significant difference involving Group 2.
Because the groups were not randomly assigned, several statistical methods were applied to assess whether the many covariables could account for any differences. The difference between Group 1 and Group 3 was maintained. These results supported the hypothesis that long term vitamin D supplementation increases COVID-19 survival in elderly hospitalized patients.
This study only supported an answer to a small slice of the question on whether vitamin D supplements can save us from COVID-19. This study suggests that they can, but strictly in cases of elderly patients who have been taking vitamin D supplements for the past year. So, while vitamin D supplements pose a potential help, there is a much more proven prevention method.
