Many patients who’ve been a part of studies implicating nutritional markers in COVID-19 severity have had low serum levels of vitamin D and calcium, two micronutrients evidenced to have crucial roles in immune function. A new clinical trial, published in the Journal of the American College of Nutrition, concluded that for patients with hypocalcemia and low levels of vitamin D, supplementation may improve the critical prognosis of these patients.
 
“It is widely recognized that COVID-19 severity is a multifactorial condition; several risk factors have been identified, including advanced age, ethnicity, type 2 diabetes, hypertension, obesity, renal dysfunction, and cardiovascular diseases. Interestingly, each of these factors is also known to be related to vitamin D deficiency in some way. This has led to raising the issue of whether inadequate vitamin D levels can affect the progression or even the prognosis of COVID-19,” the authors of the study said. “On the other side, hypocalcemia is a common in-hospital complication, which occurs concurrently with other bio-clinical disorders such as an unbalanced status of vitamin D and parathyroid hormone release, hypoproteinemia, and even chronic kidney disease.”
 
Since the onset of the COVID-19 pandemic, indirect, epidemiological evidence, such as geographical disparity, combined with clinical evidence, suggest that vitamin D levels are beneficial in modulating both the innate and adaptive immune system. However, calcium deficiency (hypocalcemia) has only been discussed anecdotally, according to the authors, despite its high prevalence in severe COVID-19 patients – it could be explained as a result of both impaired intestinal absorption and due to conditions that are prevalent in intensive care both including and excluding cases of COVID-19.
 
“In light of the above-cited data, this study was carried out to assess both vitamin D and serum calcium status among COVID-19 severely affected patients, and to test the hypothesis of a possible link between their serum levels and short-term prognosis of this affection,” the authors said.
 
In the prospective study, researchers monitored the health outcomes of 120 patients with severe cases of COVID-19, who were assessed for vitamin D using an immune-fluoroassay method. Total serum calcium was assessed using a colorimetric method, which was corrected for serum albumin levels. The authors of the study found that deficiencies in both vitamin D and calcium were very common, and occurred in 75% and 35.8% of patients respectively, and deficiencies in vitamin D (<39 nmol/L) and calcium (<2.05 nmol/L) could predict poor prognosis with 69% and 60% accuracies, respectively.
 
“The most relevant finding of this study was the revelation of a significant association between severe vitamin D deficiency as well as hypocalcemia with short-term COVID-19 mortality in ICU. This association was independent of other confounding factors with already proven prognostic value such as inflammatory markers (CRP, NLR, and neutrophils), AKI, cardiac injury, gender, and age,” the authors concluded. “It is, therefore, possible that correction of albuminemia, hypocalcemia, as well as supplementation with vitamin D may attenuate the severity and improve the vital prognosis.”