Vitamin D status of Arab Gulf residents screened for SARS‑CoV‑2 and its association with COVID‑19 infection: a multi-center case–control study.

A total of 220 individuals living in Riyadh, Saudi Arabia were screened for SARS-CoV-2 by RT-PCR testing from May 2020 to July 2020. Serum 25(OH)D levels were significantly lower in those who tested positive (n = 138) than negative (n = 82) for SARS-CoV-2, but advanced age, diabetes mellitus and low HDL cholesterol were the factors most significantly associated with the risk of COVID-19 infection.

• The negative group was significantly younger and had lower BMI compared to the SARS-CoV-2 positive group. The SARS-CoV-2 positive group had a higher prevalence of diabetes, hypertension, hyperlipidemia, hypertriglyceridemia and low-HDL than the negative group.
• Serum 25(OH)D levels were significantly lower in the SARS-CoV-2 positive group compared to the negative group after adjustment for age and BMI (52.8 nmol/l±0 versus 64.5 nmol/l±11.1).
• Advanced age (> 60 years) [Odds ratio 6 (95% Confidence Interval, CI 2–18; p = 0.001) as well as having type 2 diabetes [OR 6(95% CI 3–14); p < 0.001)] and low HDL cholesterol [OR 6 (95% CI 3–14); p < 0.001)] were significant risk factors for COVID-19 infection independent of age, sex and BMI.

A total of 220 adults (120 men, 54.5%; 100 women, 45.5%; mean age = 43±15 years) living in Riyadh, Saudi Arabia were screened for Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection by reverse transcription polymerase chain reaction (RT-PCR). Of these individuals, 138 tested positive for SARS-CoV-2 (79 men, 57.2%; 59 women 42.7%; mean age = 50±13 years); 82 tested negative (41 men, 50%; 41 women, 50%; mean age = 32 ± 13 years) and served as the control group.

• The study design limits interpretation as to whether low 25(OH)D status is a cause or a consequence of COVID-19 infection.
• While the overall sample size was robust for determining differences in the clinical characteristics of participants with or without SARS-CoV2, it had low power to detect differences if stratified further according to sex.
• The findings apply only to individuals presenting with none to mild COVID-19 symptoms, since vitamin D status maybe an unreliable indicator in moderate to severe cases, given that it behaves as a negative acute phase reactant in the presence of a major acute inflammatory insult.

Among Arab Gulf residents screened for SARS-CoV-2, serum 25(OH) D levels were observed to be lower in those who tested positive than negative individuals, but advanced age, diabetes mellitus and low HDL cholesterol were most significantly associated with the risk of COVID-19 infection.

• This was a multi-center, case–control study, conducted at King Saud University Medical City-King Khalid University Hospital and King Salman Hospital, Riyadh, Saudi Arabia, between May and July 2020.
• Only asymptomatic to mild cases were included, and participants with severe manifestations of coronavirus disease-2019 (COVID-19) (e.g., those that required intensive care) were excluded. A mild case of COVID-19 was defined as the patient not requiring oxygen on presentation and no evidence of pneumonia but with clinical symptoms such as fever.
• Medical histories were reviewed, anthropometrics were measured and non-fasting blood samples were collected for the assessment of glucose, lipids, inflammatory markers and serum 25(OH)D concentrations.
• Total serum 25(OH)D was measured using commercial electrochemiluminescence

immunoassay.

• Vitamin D deficiency was defined as serum 25(OH)D <50 nmol/l (<20 ng/ml) based on

national and regional recommendations.

Al-Daghri NM, Amer OE, Alotaibi NH, Aldisi DA, Enani MA, Sheshah E, Aljohani NJ, Alshingetti N, Alomar SY, Alfawaz H, Hussain SD, Alnaami AM, Sabico S. Vitamin D status of Arab Gulf residents screened for SARS-CoV-2 and its association with COVID-19 infection: a multi-centre case-control study. J Transl Med. 2021 Apr 26;19(1):166. doi: 10.1186/s12967-021-02838-x. PMID: 33902635; PMCID: PMC8072076.