Low vitamin D linked to high virus death rate
An association between low average levels of vitamin D and high numbers of COVID-19 cases and mortality rates across 20 European countries has been found in a new study.
The research, led by Dr Lee Smith of Anglia Ruskin University (ARU) and Mr Petre Cristian Ilie, lead urologist of Queen Elizabeth Hospital King's Lynn NHS Foundation Trust, is published in the journal Aging Clinical and Experimental Research.
The primary aims of this study are to assess if there is any association between the mean levels of vitamin D in various countries and the mortality caused by COVID-19. The secondary aim was to identify if there is any association between the mean vitamin D levels in various countries and the number of cases of COVID-19”, the authors write.
Vitamin D modulates the response of white blood cells
Previous observational studies have reported an association between low levels of vitamin D and susceptibility to acute respiratory tract infections. Vitamin D modulates the response of white blood cells, preventing them from releasing too many inflammatory cytokines. The COVID-19 virus is known to cause an excess of pro-inflammatory cytokines, reports pharmanews.eu.
Italy and Spain have both experienced high COVID-19 mortality rates, and the new study shows that both countries have lower average vitamin D levels than most northern European countries. This is partly because people in southern Europe, particularly the elderly, avoid strong sun, while skin pigmentation also reduces natural vitamin D synthesis.
The highest average levels of vitamin D are in northern Europe
The highest average levels of vitamin D are found in northern Europe, due to the consumption of cod liver oil and vitamin D supplements, and possibly less sun avoidance. Scandinavian nations are among the countries with the lowest number of COVID-19 cases and mortality rates per head of population in Europe.
We found a significant crude relationship between average vitamin D levels and the number COVID-19 cases, and particularly COVID-19 mortality rates, per head of population across the 20 European countries”`, write Dr Lee Smith, Reader in Physical Activity and Public Health at Anglia Ruskin University.
"Vitamin D has been shown to protect against acute respiratory infections, and older adults, the group most deficient in vitamin D, are also the ones most seriously affected by COVID-19.
Dedicated studies of vitamin D levels in COVID-19 patients
"A previous study found that 75% of people in institutions, such as hospitals and care homes, were severely deficient in vitamin D. We suggest it would be advisable to perform dedicated studies looking at vitamin D levels in COVID-19 patients with different degrees of disease severity."q the authors write.