More than 80% of hospital patients with Covid-19 lack vitamin D, which is among vitamins linked to fewer respiratory complaints, studies have found.
Scientists have warned that vitamin D deficiency in ‘high-risk individuals’ should be identified and treated.
New research published by the University of Cantabria last week found that 82.2% of 216 coronavirus patients tested at Hospital Universitario Marqués de Valdecill were deficient in vitamin D.
It also found that men had lower levels of the vitamin than women and that Covid patients with lower vitamin D levels also had raised serum levels of inflammatory markers, such as ferritin and D-dimer.
In contrast, out of a control group of people who didn’t have Covid-19, just 47% of people were deficient in vitamin D.
However, the research did not find a link between circulating levels of vitamin D and severity of Covid-19 infection, such as ICU admission, the need for mechanical ventilation or mortality.
Researchers recommended vitamin D treatment for ‘high-risk individuals’, such as the elderly and patients with comorbidities, as well as Covid-19 patients.
Study co-author José Hernández said: ‘[Vitamin D treatment] might have beneficial effects in both the musculoskeletal and the immune system.’
He added: ‘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.
‘Vitamin D treatment should be recommended in Covid-19 patients with low levels of vitamin D circulating in the blood.’
Deficiency in the vitamin has been linked to a variety of health concerns, although research is still underway into why the hormone impacts other systems of the body.
It comes as another study, published in the BMJ Nutrition Prevention and Health journal this week, found that higher levels of vitamins A, E and D are linked to fewer ‘respiratory complaints’ in adults.
The study analysed the data of 6,115 adult participants of the Government’s 2008–2016 National Diet and Nutrition Survey Rolling Programme – which collected annual data on all food and drink consumed by around 1,000 randomly-selected people living in private households across the UK.
It found that vitamin A and E intake from both diet and supplements was associated with a lower prevalence of respiratory complaints, while vitamin D intake from supplements only was associated with the same.
The study said: ‘It is estimated that around a fifth of the general population in the UK have low vitamin D, and over 30% of older adults aged 65 years and above do not achieve the recommended nutrient intake.
‘Our findings are consistent with the hypothesis that supplementation is critical to ensuring adequate vitamin D status is maintained and potentially indicate that intake of vitamin D from diet alone cannot help maintain adequate vitamin D status.’
However, the findings warrant further investigation in different ethnic groups and locations in light of the coronavirus pandemic, the researchers concluded.
Many studies have pointed to the beneficial effect of vitamin D on the immune system, especially regarding protection against infections.
However, in June a review by NICE concluded that there is insufficient evidence to support taking vitamin D supplements to specifically prevent or treat Covid-19.
Meanwhile, there has been a marked increase in vitamin D supplement prescriptions for children in the UK over the past decade.
Additional reporting by Mimi Launder