Analysis of vitamin D level among asymptomatic and critically ill COVID-19 patients and its correlation with inflammatory markers

In this 154 patient prospective cohort study in India, individuals with severe COVID-19 had lower vitamin D levels and were more likely to be vitamin D deficient.  Deficient patients were more likely to pass away from COVID-19 (21.0%) than those who were not vitamin D deficient (3.1%).  The study looked at deficiency, but does not demonstrate the effect of vitamin D supplementation on COVID-19 and results were not adjusted for potential cofounding factors, such as age.  

• 154 COVID-19 patients aged 30-60 y  in India during June and July 2020.  
• The subjects were separated into two groups.  
  • Group A included 91 COVID-19 patients with no symptoms, 53 were men, 48 were female, with an average age of  42.3, who remained in an isolation ward for 12 days.  
  • Group B included 63 COVID-19 patients, 42 were men, 21 were female with an average age of 51.4. These patients were severely ill patients and required admission to the intensive care unit (ICU).  
  • The patients admitted to the ICU (Group B) were significantly older and male.  
• In both Group A and B, diabetes was the most common disease they had other than COVID-19, followed by hypertension.  

6 weeks

• The mean concentrations of 25(OH)D was significantly higher in Group A (the group with no symptoms but in isolation) (27.89 ± 6.21 ng/ml) compared to Group B the group in ICU (14.35 ± 5.79 ng/ml).  
• Using a serum concentration of <20 ng/ml 25(OH)D as a cutoff value for vitamin D deficiency 
  • 31.86% of Group A were classified as vitamin D deficient 
  • 96.82 % of Group B were classified as vitamin D deficient  
  • Out of a total of 154 patients, 90 patients were found to be deficient in vitamin D, 61 were critical, 29 had no symptoms.    
• Severe vitamin D deficiency was further defined as <10 ng/ml.  
  • A total of 62 patients were found to be severely deficient in vitamin D;  
  • 52 were critical and 10 had no symptoms.  
  • Two critical patients had normal levels of vitamin D.  
• Patients with low vitamin D blood levels had significantly higher markers of inflammation than those with higher vitamin D levels.  
• 1.1% (1 death) of those in Group A passed away.  
• Group B 31.7% passed away (20 deaths).  
• When deaths were calculated on the basis of vitamin D deficiency,  
  • the fatality rate in vitamin D deficient patients was 21.0% (19 deaths/90 patients)  
  • 3.1% in patients with normal vitamin D levels (2 deaths/64 patients). 

This was a single center study of just a few subjects, all of whom tested positive for COVID-19 which may affect the results and may not be applicable to the entire population. Other than age the researchers did not determine what other factors may have influenced outcomes besides vitamin D. For example, it would be interesting to know if the subjects deficient in vitamin D were deficient in any other nutrients. 

The results of this study suggest that the chance of passing away from COVID-19 is greater in those who are vitamin D deficient (21.0%) than those who are not vitamin D deficient (3.1%). 

After admission to either the isolation ward or ICU, blood samples were obtained and levels of the principal vitamin D metabolite, 25-hydroxyvitamin D [25(OH)D], were measured, no intervention was done for vitamin D.

Jain A, Chaurasia R, Sengar NS, Singh M, Mahor S, Narain S. Analysis of vitamin D level among asymptomatic and critically ill COVID-19 patients and its correlation with inflammatory markers. Sci Rep. 2020 Nov 19;10(1):20191. doi: 10.1038/s41598-020-77093-z. PMID: 33214648; PMCID: PMC7677378. https://pubmed.ncbi.nlm.nih.gov/33214648/