Over 80% of 200 COVID-19 patients in a hospital in Spain have vitamin D deficiency, according to a study.
Serum 25-hydroxyvitamin D (25OHD) is a hormone the kidneys produce that controls blood calcium concentration and impacts the immune system. Vitamin D deficiency has been linked to a variety of health concerns, although research is still underway into why the hormone impacts other systems of the body. Many studies point to the beneficial effect of vitamin D on the immune system, especially regarding protection against infections.
"One approach is to identify and treat vitamin D deficiency, especially in high-risk individuals such as the elderly, patients with comorbidities, and nursing home residents, who are the main target population for the COVID-19," said study co-author Dr José L Hernández, of the University of Cantabria in Santander, Spain. "Vitamin D treatment should be recommended in COVID-19 patients with low levels of vitamin D circulating in the blood since this approach might have beneficial effects in both the musculoskeletal and the immune system."
The researchers found 80% of 216 COVID-19 patients at the Hospital Universitario Marqués de Valdecilla had vitamin D deficiency, and men had lower vitamin D levels than women. COVID-19 patients with lower vitamin D levels also had raised serum levels of inflammatory markers such as ferritin and D-dimer.
The manuscript received funding from Instituto de Salud Carlos III.
Background: The role of vitamin D status in COVID-19 patients is a matter of debate.
Objectives: To assess serum 25-hydroxyvitamin D (25OHD) levels in hospitalized patients with COVID-19 and to analyze the possible influence of vitamin D status on disease severity.
Methods: Retrospective case-control study of 216 COVID-19 patients and 197 population-based controls. Serum 25OHD levels were measured in both groups. Besides, the association of serum 25OHD levels with COVID-19 severity (admission to the Intensive Care Unit, requirements for mechanical ventilation, or mortality) was also evaluated.
Results: Of the 216 patients, 19 were on vitamin D supplements and were analyzed separately. In COVID-19 patients, mean±SD 25OHD levels were 13.8±7.2 ng/ml, compared to 20.9±7.4 ng/ml in controls (p<0.0001). 25OHD values were lower in men than in women. Vitamin D deficiency was found in 82.2% of COVID-19 cases and 47.2% of population-based controls (p<0.0001). 25OHD inversely correlate to serum ferritin (p=0.013) and D-dimer levels (p=0.027). Vitamin D-deficient COVID-19 patients had a greater prevalence of hypertension and cardiovascular diseases, raised serum ferritin and troponin levels, as well as a longer length of hospital stay than those with serum 25OHD levels ≥20 ng/ml. No causal relationship was found between vitamin D deficiency and COVID-19 severity as a combined endpoint or as its separate components.
Conclusions: 25OHD levels are lower in hospitalized COVID-19 patients compared to population-based controls and these patients had a higher prevalence of deficiency. We did not find any relationship between vitamin D concentrations or vitamin deficiency and the severity of the disease.
José L Hernández, Daniel Nan, Marta Fernandez-Ayala, Mayte García-Unzueta, Miguel A Hernández-Hernández, Marcos López-Hoyos, Pedro Muñoz Cacho, José M Olmos, Manuel Gutiérrez-Cuadra, Juan J Ruiz-Cubillán, Javier Crespo, Víctor M Martínez-Taboada