The Impact of Serum Levels of Vitamin D3 and Its Metabolites on the Prognosis and Disease Severity of COVID-19.

Vitamin D is among the increasingly consumed dietary supplements during the COVID-19 pandemic. It plays a regulatory role in the immune system and moderates the renin-angiotensin system, which is implicated in infection pathogenesis. However, the investigation of serum levels of vitamin D3 forms and their relative ratios in COVID-19 patients is worth investigation to understand the impacts of disease severity. Hence, we investigated the serum levels of vitamin D3 (cholecalciferol) and its metabolites (calcifediol and calcitriol), in addition to their relative ratios and correlations with angiotensin-converting enzyme 2 (ACE2), interleukin-6 (Il-6), and neutrophil-lymphocyte ratio (NLR) in COVID-19 patients compared with healthy controls. Oropharyngeal specimens were collected from the study subjects for polymerase chain reaction testing for COVID-19. Whole blood samples were obtained for blood count and NLR testing, and sera were used for the analysis of the levels of the vitamin and its metabolites, ACE2, and IL-6. We enrolled 103 patients and 50 controls. ACE2, Il-6, and NLR were significantly higher in the patients group (72.37 ± 18.67 vs. 32.36 ± 11.27 U/L, 95.84 ± 25.23 vs. 2.76 ± 0.62 pg/mL, and 1.61 ± 0.30 vs. 1.07 ± 0.16, respectively). Cholecalciferol, calcifediol, and calcitriol were significantly lower in patients (18.50 ± 5.36 vs. 29.13 ± 4.94 ng/mL, 14.60 ± 3.30 vs. 23.10 ± 3.02 ng/mL, and 42.90 ± 8.44 vs. 65.15 ± 7.11 pg/mL, respectively). However, their relative ratios were normal in both groups. Levels of the vitamin and metabolites were strongly positively, strongly negatively, and moderately negatively correlated with ACE2, Il-6, and NLR, respectively. COVID-19 infection severity is associated with a significant decrease in vitamin D3 and its metabolites in a parallel pattern, and with a significant increase in ACE2, Il-6, and NLR. Higher levels of vitamin D and its metabolites are potentially protective against severe infection.

An ultrasensitive UHPLC-ESI-MS/MS method augmented with a controlled microwave derivatization reaction for quantitation of vitamin D3 and its major metabolites in COVID-19 patients.

It is established that vitamin D deficiency is correlated with the disease severity in COVID-19 patients. However, the reliable and sensitive quantitation of vitamin D3 (D3) and its metabolites remains a difficult challenge. Herein, a novel ultrasensitive and reliable UHPLC-ESI-MS/MS method was developed and validated for the quantitation of D3 and its major metabolites in COVID-19 patients. The mass spectral sensitivity was augmented via controlled microwave-assisted derivatization reaction (CMDR) with 2-nitrosopyridine (Pyr-NO) at 65 °C for 2 min. CMDR hyphenation with UHPLC-MS/MS improves detection sensitivity while shortening separation and derivatization reaction times. The precursor to product ion transitions for D3, 25-hydroxy D3 (25(OH)D3), 1,25-dihydroxy D3 (1,25-(OH)2D3) and calcipotriol (CPT) as an internal standard were m/z 493.4 â†’ 231.3, m/z 509.4 â†’ 231.3, m/z 525.4 â†’ 247.3, and m/z 521.4 â†’ 247.3; respectively. The separation of the formed derivatives was conducted using a gradient elution mode with mobile phase A: formic acid (0.1%) in water and mobile phase B: formic acid (0.1%) in acetonitrile. The elution started with 40% (v/v) of B for 0.3 min then increased linearly to 90% (v/v) at 2 min on an Agilent EclipsePlus C18 (50 × 2.1 mm, 1.8 µm) column at a flow rate of 0.3 mL min-1. The method was validated using FDA standards for bioanalytical method validation over a concentration range of 0.02-50 ng mL-1 with correlation coefficient ≥0.9987 and the lower limit of quantitation (LLOQ) were 0.02-0.05 ng mL-1 in human plasma. The developed method has demonstrated excellent comparability to a well-established chemiluminescent immunoassay (CLIA) method for the analysis of D3 metabolites in human samples. The developed UHPLC-ESI-MS/MS method was implemented for routine and reliable quantitation of D3 and its major metabolites in COVID-19 patients.

A nationwide study on the knowledge, awareness, and practices towards COVID-19 in Saudi Arabia

AJOL Abstract: Purpose: To investigate public knowledge, awareness and practice regarding COVID-19 in Saudi Arabia.Methods: A cross-sectional descriptive study was conducted, with a 16-item self-administered questionnaire. Data was collected using social media as the platform a day after the lockdown commenced in Saudi Arabia and data collection lasted from March 25 to April 25, 2020. Chi-square test was performed to determine the association between the variables.Results: The results showed that 96 % (n = 1505) of adults were aware of the clinical symptoms of COVID-19 and 57.9 % (n = 908) correctly identified that a stuffy nose and sneezing were less common in persons infected with the virus. A majority (95.4 %, n = 1495) agreed that there was no established therapeutic treatment for COVID-19. Further, 91.7 % (n = 1437) agreed that the virus could spread via respiratory droplets and only 46.2 % (n = 724) acknowledged that wearing face mask helped prevent transmission. The results also showed that 83.2 % (n = 1299) of the participants thought that visiting crowded places increased the likelihood of transmission.Conclusion: The findings of this study reveal that adults in Saudi Arabia are cognizant of COVID-19 and maintained good attitudes and practices regarding it. Furthermore, health education programs aimed at improving awareness of the disease and appropriate control measures will be beneficial in curbing the virus pandemic