Previous research early in the pandemic suggested that vitamin D reduces the risk of contracting Covid-19. However, a new study by McGill University in Canada has revealed that there is no genetic evidence that the vitamin works as a preventative measure against coronavirus.
To assess the relationship between vitamin D levels and the severity of Covid-19, the scientists examined the genetic variants of 14,134 people from 11 countries who contracted Covid-19 and more than 1.2 million people without the disease.
In the study, published in the scientific journal PLOS Medicine, researchers found no difference between vitamin D levels in people with the disease and the likelihood of being hospitalized or seriously ill.
“Vitamin D supplementation as a public health measure to ameliorate the effects of Covid-19 is not supported by this study. Most importantly, our results suggest that investment in other therapeutic or preventive avenues should be prioritized for Covid-19 randomized clinical trials,” the study authors said.
Early in the pandemic, many researchers were investigating the effects of vitamin D, which plays a critical role in a healthy immune system. However, there is still insufficient evidence that taking supplements can prevent or treat Covid-19 in the general population.
Therefore, the study’s authors concluded, “So the best way to answer the question of the effect of vitamin D would be randomized trials, but they are complex and require large resources and also take a long time.”
On the other hand, the researchers said that using Mendelian randomization, they were able to reduce the potential bias from these known risk factors and provide a clearer picture of the relationship between vitamin D and Covid-19.
However, the researchers noted that their study has some important limitations. The study did not account for patients who were truly vitamin D deficient. In addition, only genetic variants of individuals of European descent were analyzed in the study. The study’s authors said that future studies are needed to explore the association with vitamin D and Covid-19 outcomes in other populations.
It is thought that around 1 billion people worldwide suffer from vitamin D deficiency. Experts worry that the number could rise as quarantine practices reduce sunlight intake. Vitamin D deficiency and insufficiency is recognized as a global health problem by the World Health Organization.
However, 9 out of 10 people in Turkey have vitamin D deficiency. Experts say that if there is weakness, fatigue and recurring infections, a doctor should be consulted. Vitamin D is produced when the skin is exposed to sunlight and is necessary for a healthy immune system.