Here we report our findings in 10 patients with confirmed COVID-19 infection hospitalized patients from Bethesda Hospital, Yogyakarta Indonesia. Patients in this case were conducted from 50% (5 patients) male and 50% (5 patients) female with an average age of 49.6 years. The incubation period for COVID 19 in this case is 2-14 days. Our study showed that elderly and female tends to have lower vitamin D status. This is relevant with the facts on vitamin D and COVID-19. Serum 25(OH)D concentrations tend to decrease with age [8]. In COVID-19 case-fatality rates (CFRs) increase with age [9].
We found out that COVID-19 patients in this case had several comorbidities which are chronic diseases such as hypertension, diabetes, COPD, and post stroke. Some studies report that people with chronic disease co-morbidities have lower 25(OH)D than healthy people [10]. Case Fatality Rate (CFR) in China is 6%-10% for those with cardiovascular disease, hypertension, diabetes, and chronic respiratory diseases [9].
In this case series, we evaluated vitamin D status in 10 patients with COVID-19. Examination of vitamin D levels was carried out by blood tests in the laboratory. From 10 patients, we found 90% (9 patients) with vitamin D deficiency and 10% (1 patient) with vitamin D insufficiency. Some of the patients have very severe deficiency. Similar to our findings, previous studies reported COVID-19 patients among ICU subjects, 11 (84.6%) had Vitamin D insufficiency vs 4 (57.1%) of floor subjects. Surprisingly, 100% of ICU patients who are less than 75 years old have Vitamin D Insufficiency (n = 11). Among these, 64.6% (n = 7) had very low 25(OH)D levels <20 ng / mL and three had 25(OH)D levels <10 ng / mL [11].
Recent study from Martineau, et al. were performed a meta-analysis from 25 randomized controlled trials (10.933 participants). There was a statistically significant reduction found from vitamin D supplementation in the risk of having acute respiratory infection. In subgroup analysis, they found a protective effect in daily or weekly supplementation but not in bolus doses. There was a strong protective effect in those with 25(OH)D levels <10 ng/mL and there was no significant effect in those with serum 25(OH)D >10 ng/mL. There were an inverse relationship between serum vitamin D levels and risk of acute respiratory tract infection [7]. It means, low vitamin D levels may contribute to increased risk of respiratory infection including COVID-19 [12].
Previous report have speculated that people with low serum vitamin D might be at higher risk of infection with COVID-19, or will be worsen when infected [13]. There is an overlap between groups at high risk of Vitamin D deficiency and groups at high risk of severe COVID-19. Examples include people with chronic disease, and elderly. Our studies showed that some of the COVID-19 cases were elderly, and have chronic disease.
The seasonality of many viral infections, one of them is a respiratory viral infection, is associated with a low concentration of 25(OH)D, as result a UVB doses are low because of winters in temperate climates and rainy seasons related in tropical climates [14]. Our study showed that all patients have deficient and insufficient status of vitamin D. The surprising facts in tropical country that very rich with sun.
Vitamin D have possible beneficial effects in the immune system especially in COVID-19 patient. For example, vitamin D will increase the production of various peptides by the innate immune system, which has anti-viral, anti-microbial and anti-fungal activity [15]. Vitamin D has been proven to not only reduce the production of proinflammatory Th1 cytokines but also to increase the expression of anti-inflammatory cytokines by macrophages. This may be worth bearing in mind the proinflammatory cytokine environment observed in patients infected with COVID-19 and how the "cytokine storm" that leads to acute respiratory distress syndrome [16].
We found no trials of Vitamin D in COVID-19 that have reported results. We did find several studies that are registered, but have not yet reported. One trial is testing whether a single oral dose of 25,000 IU (625 µg) of vitamin D will improve mortality in patients who are infected with SARS-CoV-2 but do not have severe symptoms, compared with usual care [17]. Another RCT will compare single doses of vitamin D3, 50,000 IU to 200,000 IU (1250 Vs 5000 µg) in people with COVID-19 pneumonia who are over 75 years of age, or over 70 with low oxygen saturations; the primary outcome measure is mortality at 14 days [18].
We found no clinical evidence that vitamin D supplements are beneficial in preventing or treating COVID-19. We would need evidence from well-masked randomized trials to determine if there are effects, before recommending vitamin D3 supplements for treating or preventing COVID-19 infection. The hypothesis that vitamin D supplementation can reduce the risk of influenza and COVID-19 incidence and death should be investigated in trials to determine the appropriate doses, serum 25(OH)D concentrations, and the presence of any safety issues.
People at risk of vitamin D deficiency should in any case take supplements in line with current guidance. In our case series we treat all our patient with 2000 IU oral supplementation. As clinicians, we should continue to treat people with vitamin D deficiency, but not because of any possible association with respiratory infection.