New findings on ambient UVB radiation, vitamin D, and protection against severe COVID-19

Date:
September 15, 2021
Source:
Trinity College Dublin
Summary:
New research has examined the association between vitamin D and
COVID-19, and found that ambient ultraviolet B (UVB) radiation
(which is key for vitamin D production in the skin) at an
individual's place of residence in the weeks before COVID-19
infection, was strongly protective against severe disease and death.



FULL STORY ==========================================================================
New research from Trinity College Dublin and University of Edinburgh
has examined the association between vitamin D and COVID-19, and found
that ambient ultraviolet B (UVB) radiation (which is key for vitamin D production in the skin) at an individual's place of residence in the weeks before COVID-19 infection, was strongly protective against severe disease
and death. The paper has been published in the journal Scientific Reports.


========================================================================== Previous studies have linked vitamin D deficiency with an increased susceptibility to viral and bacterial respiratory infections. Similarly, several observational studies found a strong correlation between
vitamin D deficiency and COVID-19, but it could be that these effects
are confounded and in fact a result of other factors, such as obesity,
older age or chronic illness which are also linked with low vitamin D.

To overcome this, researchers were able to calculate
"genetically-predicted" vitamin D level, that is not confounded by other demographic, health and lifestyle factors, by using the information from
over one hundred genes that determine vitamin D status.

The Mendelian Randomisation is a particular analytical approach that
enabled researchers to investigate whether vitamin D and COVID-19 might
be causally linked using genetic data. Few earlier studies attempted this
but failed to show a causal link. This could be because UVB radiation
sunshine which is the most important source of vitamin D for majority
of people was ignored.

Researchers, for the first time, looked jointly at genetically-predicted
and UVB-predicted vitamin D level. Almost half a million individuals in
the UK took part in the study, and ambient UVB radiation before COVID-19 infection was individually assessed for each participant. When comparing
the two variables, researchers found that correlation with measured
vitamin D concentration in the circulation was three-fold stronger for UVB-predicted vitamin D level, compared to genetically-predicted.

Researchers found that ambient UVB radiation at an individual's place
of residence preceding COVID-19 infection was strongly and inversely
associated with hospitalisation and death. This suggests that vitamin D
may protect against severe COVID-19 disease and death. Additionally, while
the results from the Mendelian Randomisation analysis weren't conclusive,
some indication of a potential causal effect was noted. Because of the relatively weak link between genetically-predicted vitamin D level that is
used for Mendelian Randomisation analysis, it is possible that the number
of cases in the current study was too small to convincingly determine
causal effect, but future larger studies might provide the answer.

Professor Lina Zgaga, Associate Professor in Epidemiology, School of
Medicine, Trinity College and senior researcher on the study said:
"Our study adds further evidence that vitamin D might protect
against severe COVID-19 infection. Conducting a properly designed
COVID-19 randomised controlled trial of vitamin D supplementation
is critical. Until then, given that vitamin D supplements are safe
and cheap, it is definitely advisable to take supplements and protect
against vitamin D deficiency, particularly with winter on the horizon." Professor Evropi Theodoratou, Professor of Cancer Epidemiology and
Global Health, University of Edinburgh and senior researcher on the
study said: "Given the lack of highly effective therapies against
COVID-19, we think it is important to remain open-minded to emerging
results from rigorously conducted studies of vitamin D." Dr Xue Li,
a researcher on the study from Zhejiang University said: "Our study
supports the recommendation of vitamin D supplementation for not only
the maintenance of bone and muscle health during the lock down, but
also the potential benefits in relation to protection from COVID-19." ========================================================================== Story Source: Materials provided by Trinity_College_Dublin. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Xue Li, Jos van Geffen, Michiel van Weele, Xiaomeng Zhang,
Yazhou He,
Xiangrui Meng, Maria Timofeeva, Harry Campbell, Malcolm
Dunlop, Lina Zgaga, Evropi Theodoratou. An observational
and Mendelian randomisation study on vitamin D and COVID-19
risk in UK Biobank. Scientific Reports, 2021; 11 (1) DOI:
10.1038/s41598-021-97679-5 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/09/210915095408.htm

--- up 1 week, 6 days, 8 hours, 25 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)