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Vitamin D sufficiency, a serum 25- hydroxyvitamin D at least 30 ng/mL reduced risk for adverse clinical outcomes in patients with COVID-19 infection
Take Home Message
Vitamin D sufficiency, a serum 25- hydroxyvitamin D at least 30 ng/mL reduced risk for adverse clinical outcomes in patients with COVID-19 infection.
Results
- 2% of the patients had a 25(OH)D level of less than 30ng/mL.
- Vitamin D sufficiency was associated with a statistically significant lower risk of unconsciousness and hypoxia, defined by an arterial blood oxygen saturation levels below 90%. The serum CRP and lymphocyte percentage in the blood were significantly lower and higher respectively in patients who were vitamin D sufficient.
- There were no significant differences in hospitalization duration and ICU admissions between patients with and without vitamin D sufficiency.
- 3% of patients 40 years and older succumbed to the infection.
- Of the 206 patients who were 40 years and older, 20% had a blood level of 25(OH)D <30 ng/mL whereas only 9.7% who perished had a blood level of 25(OH)D of at least 30 ng/mL.
- Only 6.3% of the patients over 40 years of age died with a blood level of 25(OH)D of 40 ng/mL or higher.
- Severe disease infection was less prevalent in patients with vitamin D sufficiency (63.6% vs. 77.2%).
- After adjusting for age, sex, BMI, smoking and history of a chronic medical disorder, there were significant independent associations between vitamin D sufficiency and lower BMI with decreased disease severity.

Who
235 patients infected with COVID-19. The patients were 18 years of age and older with acute respiratory tract infection symptoms (e.g. fever, cough, dyspnea).
Things to Keep in Mind
This is a cross-sectional analysis, no intervention took place and there are no controls. No conclusions can be drawn just relationships that suggest the need for future interventional trials.
Author’s Conclusions
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A blood level of at least 40 ng/mL may be optimal for vitamin D’s immunomodulatory effect. Therefore, based on the available literature and results from this study it is reasonable to recommend vitamin D supplementation, along the guidelines recommended by the Endocrine Society to achieve a blood level of 25(OH)D of at least 30/mL, to children and adults to potentially reduce risk of acquiring the infection and for all COVID-19 patients especially those being admitted into the hospital.
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Study Design
- The hospital data of 235 patients infected with COVID-19 was analyzed.
- This is a cross-sectional analysis of a COVID-19 database in Sina hospital, Tehran, Iran.
- CDC criteria were used for the disease severity and prognosis; which includes mild-moderate (mild respiratory symptoms and fever, on an average of 5–6 days after infection), severe disease (dyspnea, respiratory frequency ≥30/minute, blood oxygen saturation ≤ 93%, and/or lung infiltrates >50% of the lung field within 24–48 hours) and critical (respiratory failure, septic shock, and/or multiple organ dysfunction/failure). Patients with at least two complications, including acute respiratory distress syndrome (ARDS), acute cardiac injury (ACI), acute kidney injury (AKI) or acute liver injury consider as multiple organ damage. Hypoxia defines as an arterial blood oxygen saturation levels below 90%. Severe and critical categories were defined “severe” in data analysis.
- Demographic and lab test upon admission were recorded.
- Overall, a cutoff point of 30 ng/mL was used for the definition of vitamin D sufficiency based on the Endocrine Society’s Practice Guidelines on Vitamin D that defined vitamin D deficiency and insufficiency as a circulating level of 25(OH)D of <20 ng/mL and 20–29 ng/mL respectively.
Reference
Maghbooli Z, Sahraian MA, Ebrahimi M, Pazoki M, Kafan S, Tabriz HM, Hadadi A, Montazeri M, Nasiri M, Shirvani A, Holick MF. Vitamin D sufficiency, a serum 25-hydroxyvitamin D at least 30 ng/mL reduced risk for adverse clinical outcomes in patients with COVID-19 infection. PLoS One. 2020 Sep 25;15(9):e0239799. doi: 10.1371/journal.pone.0239799. PMID: 32976513; PMCID: PMC7518605.