COVID-19 severity in relation to sociodemographics and vitamin D use.

The aims of this observational study of 428 recovered COVID-19 patients in Iraq, conducted by online questionnaire, were to evaluate COVID-19 severity and relate severity of disease to sociodemographic characteristics and the use of prophylactic dietary supplements. Prophylactic vitamin D use was a significant predictor of COVID-19 severity; the prophylactic use of vitamin D predicted less severe COVID-19 disease. The proportion of hospital visits for patients who received prophylactic vitamin D supplements was statistically lower in comparison with patients who did not receive supplements (32.3% for vitamin D vs 46.0% for no vitamin D).

• According to the general severity rating for COVID-19, 285 (70%) participants were within the mild-moderate group, and 122 (30%) were in the severe group.
• Advanced age and the presence of comorbidities were the most significant positive predictors of disease severity.
• One hundred twenty-seven (29.7%) participants used vitamin D supplements before contracting COVID-19. Thirty-nine participants (30.7%) took a daily dose <1,000 IU, 49 (38.6%) took 1,000-4,000 IU/day, 28 (22%) took >4,000 IU/day, and 11 (8.7%) could not recall the dose.
• Prophylactic vitamin D use was a significant predictor of COVID-19 severity; the prophylactic use of vitamin D predicted less severe COVID-19 disease.
• The proportion of hospital visits for patients who received prophylactic vitamin D supplements was statistically lower in comparison with patients who did not receive supplements (32.3% for vitamin D vs 46.0% for no vitamin D).
• No significant difference was observed between the patients with and without prophylactic use of vitamin D in terms of the hospitalization, use of medication, use of plasma, or use of oxygen therapy.

Included in this study were 428 patients (190 males, 44.4%; 238 females, 55.6%) in Sulaymaniyah, Iraq who had recovered from COVID-19. The median age was 33 years, ranging from 15-80 years.

• Because it is a patient-based survey, the data are more subjective than objective and affected by the personal perspectives, emotions and ratings of severity of patients.
• Patients’ recall of their use of prophylactic supplements prior to infection, their symptoms and the severity of disease during the infection, could be inaccurate as the data were collected after complete recovery from COVID-19.
• Another limitation of this study is the relatively small sample size that did not  allow for proper analysis of several parameters including dose of supplementary medications, especially after stratification by age and BMI.
• Few elderly or pediatric patients participated in this study.
• Not all patients were RT-PCR confirmed cases of COVID-19. Some patients were diagnosed based on typical high-resolution computed tomography or on typical symptoms, their contact history in combination with chest x-ray, and/or serology.
• Vitamin D supplementation was not substantiated by serum 25-hydroxyvitamin D levels.

Stress, age and the presence of comorbidities were the most important positive predictors of COVID-19 severity, while prophylactic vitamin D use and smoking were significant negative predictors. The use of protective measures and other prophylactic dietary supplements were not significantly associated with symptom severity.

• This was an observational study of a sample of patients who recovered from COVID-19 that was conducted in the Sulaymaniyah Governorate, Iraq between July and August 2020 through an online patient-based survey.
• The questionnaire asked about the following topics: general and personal patient characteristics; place of residence, work and risk; the use of protective measures; prophylactic drug and dietary supplements; and COVID-19 severity and symptom profile.

Abdulateef DS, Rahman HS, Salih JM, Osman SM, Mahmood TA, Omer SHS, Ahmed RA. COVID-19 severity in relation to sociodemographics and vitamin D use. Open Med (Wars). 2021 Apr 8;16(1):591-609. doi: 10.1515/med-2021-0273. PMID: 33869781; PMCID: PMC8034240.