COVID-19 spread across the world, like a wildfire during the first half of the year 2020. It coincided with the flu season in countries located in northern and southern latitudes, during their respective winter periods. Whereas in the middle east, during its summertime people develop hypovitaminosis D, when people completely avoid the sun due to extreme heat. Consequently, people stay away from the hot sun and consequently, vitamin D concertation and the innate immunity reduce, increaseing the risks of acquiring respiratory viral infections. Thus, it is not necessary the low temperature and high humidity but the lack of exposure to ultraviolet (UV) B rays from the sunlight that reduces the population vitamin D concentration, which weakens the immunity, thereby increasing the risk of contracting COVID-19, and to develop associated complications and deaths. The effective public health modes for prevention of COVID-19 includes, wearing face masks properly covering nose and mouth, avoid crowd gatherings, especially in enclosed spaces, washing hands each time returned to office or home, and having a balance diet with adequate micronutrients, and these use of UVC lamps. At present there is no specific antiviral, or safe, effective, and affordable vaccine against COVID-19; it is unlikely such would materialize during the year 2020 or even beyond. At present, the only proven intervention that prevent COVID-19 and reduces its complications and deaths is vitamin D.
Vitamin D modulation of innate immune responses to respiratory viral infections
