Has vitamin D been shown to reduce the chance of contracting some respiratory infections?
Vitamin D deficiency can weaken the immune system and reduce the body's ability to fight infections. It has been linked to respiratory infections such as pneumonia, tuberculosis and bronchiolitis.
Researchers have suggested that vitamin D deficiency may be associated with higher mortality from COVID-19, based on observed geographic and demographic patterns as the pandemic has unfolded. But they note that giving extra doses of vitamin D to sick patients has not been proved to be an effective treatment.
Cleveland Clinic advises treating such findings with caution. "We just don’t have enough information right now," says Dr. Donald Ford. "In countries where people had lower levels of vitamin D, there were more cases of COVID-19. But this doesn’t take into account the million other factors that could be contributing to that."
