Coronavirus Resistance Linked to Plenty of Sunshine

  • By Lee Young-wan

    January 02, 2021 08:59

    Sunlight could be a life-saver amid the coronavirus epidemic as studies show that vitamin D is essential in boosting the immune system against the disease.

    One study even shows that coronavirus infections decline on sunny days. A team of researchers led by Jonathan Proctor at Harvard University showed that the coronavirus "spreads faster in the winter when it's darker with lower levels of UV radiation than during summer."

    The team found that the increase rate of coronavirus infections fell an average of seven percent in the summer. The researchers studied coronavirus infection rates in 173 countries to gather the data.

    The rate of increase fell 7.4 percent in the northern hemisphere from January to June, when ultraviolet levels increase. In contrast, the number increased 7.4 percent from July to December when ultraviolet levels decrease there. The opposite trend was seen in the southern hemisphere.

    Ultraviolet light from natural sunlight with wavelengths capable of killing viruses are blocked by the ozone layer. That means ultraviolet light cannot directly kill viruses. But it boosts resistance to viruses because the body synthesizes vitamin D when exposed to sunlight.

    A study in the Journal of Clinical Endocrinology and Metabolism in October last year of 216 coronavirus patients in Spain showed that 82 percent of them lacked vitamin D.

    Patients with low vitamin D levels excreted excessively-high levels of cytokine, resulting in higher instances of fatal reactions to infections. This is known as the "cytokine storm."

    And Michael Holick at Boston University published a study last September showing that people with vitamin D deficiencies were more than 50 percent more at risk of coronavirus infections. 

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