Vitamin D deficiency as a predictor of poor prognosis in patients with acute respiratory failure due to COVID-19

Vitamin D deficiency and obesity increases risk of testing positive for COVID-19.

To analyze vitamin D levels in patients with acute respiratory failure due to COVID-19 and to assess any correlations with disease severity and prognosis.

• 52% of the patients never smoked; 43% were ex-smokers for more than 15 years; two patients were current smokers. 86% had at least one other illness, hypertension was the most frequent, followed by cardiovascular diseases, kidney disease, and diabetes. Pulmonary illnesses other than those associated with COVID-19 were not common: five patients (12%) had chronic obstructive pulmonary disease (COPD), two (5%) had asthma. Nine patients (21%) were obese (BMI ≥ 30 kg/m²).
• 81% of patients had vitamin D serum level below 30 ng/mL, with mean serum levels of 20.46 ± 11.6 ng/mL. 19% of patients did have low vitamin D, 26% had insufficiency, 31% had moderate deficiency, and 24% had severe deficiency.
• There were no statistically significant differences between the groups in markers of inflammation or respiration.
• After 10 days, patients with severe vitamin D deficiency had a 50% probability of dying, while those with vitamin D ≥ 10 ng/mL had a 5% mortality risk.
• Advanced age and elevated levels of inflammatory markers and poor respiratory function were also increased mortality.

42 hospitalized adults (71% male and 29% female; mean age was 65 ± 13 years) whom were admitted to the RICU of the Hospital Policlinic of Bari, Italy from March 11 through April 30, 2020. Only laboratory confirmed cases, with acute respiratory failure and no need of intubation or invasive ventilation in Intensive Care Unit (ICU) were hospitalized in the RICU and included in this analysis.

This was a small study in single center with a very short follow up.

The results of our study show a high prevalence of hypovitaminosis D in COVID-19 patients treated in a RICU. Higher risk of mortality was found in patients with severe vitamin D deficiency. Further studies need to be conducted on a larger population, to demonstrate whether adjunctive treatment with vitamin D might be effective in improving disease outcomes and in reducing mortality risk.

• This was an observational single center study, meaning there was no intervention.
• It was a review of the medical records of hospitalized adults that were admitted to the RICU during the time period studied.
• Serum 25(OH)D concentration was measured.
• Vitamin D insufficiency, moderate deficiency, and severe deficiency were defined as 25(OH)D levels of 20–29, 10–19, and < 10 ng/mL, respectively.
• Based on vitamin D levels, patients were categorized into four groups: vitamin D ≥ 30 ng/mL in patients without hypovitaminosis D (group 1); 30 > vitamin D ≥ 20 ng/mL in patients with insufficiency (group 2); 20 > Vitamin D ≥ 10 ng/mL in patients with moderate deficiency (group 3); vitamin D < 10 ng/mL in patients with severe deficiency (group 4).

Carpagnano GE, Di Lecce V, Quaranta VN, Zito A, Buonamico E, Capozza E, Palumbo A, Di Gioia G, Valerio VN, Resta O. Vitamin D deficiency as a predictor of poor prognosis in patients with acute respiratory failure due to COVID-19. J Endocrinol Invest. 2021 Apr;44(4):765-771. doi: 10.1007/s40618-020-01370-x. Epub 2020 Aug 9. PMID: 32772324; PMCID: PMC7415009.