A study on nearly half a million people in the UK found that UVB radiation strongly protects people against COVID-19 hospitalization and death.
The sun’s Ultraviolet B (UVB) radiation is the key for the production of 25-OHD known as calcifediol, the active form of vitamin D.
The study looked at the protective effect of ambient UVB radiation on individuals before COVID-19 infection.
The results showed that vitamin D produced in the skin from exposure to UVB radiation (vitD-UVB) was strongly and inversely associated with COVID-19 hospitalization and death.
Past studies suggest that vitamin D deficiency increases the risk of viral and bacterial respiratory infections.
During the pandemic several studies have found a strong link between vitamin D deficiency and coronavirus infection.
However, factors such as obesity, being elderly, and chronic conditions have been linked to lower levels of vitamin D and so higher severity of COVID-19.
The study shows that vitamin D status comes from both genetic predisposition and lifestyle factors.
Previous studies have failed to show the link between vitamin D and COVID-19 using genetic data.
This may be related to the fact that UVB radiation from the sunlight, which is the main source of vitamin D for most people, was overlooked.
Professor Lina Zgaga, the study’s co-author, said:
“Our study adds further evidence that vitamin D might protect against severe COVID-19 infection.
Conducting a properly designed COVID-19 randomized 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.”
Vitamin D is crucial for the immune system: it improves the body’s defence response against infections, helps avert respiratory infections, and reduces the need for antibiotics.
According to another study, a sufficient level of vitamin D could halve the risk of catching coronavirus and protect COVID-19 patients from the worst of the disease.
The study was published in the journal Scientific Reports (Li et al., 2021).