Does vitamin D status affect corona infection risk?

Spread the love

Read Time:3 Minute, 45 Second

Word is circulating on the Internet that vitamin D supplements can protect you from infection with the coronavirus. That sounds tempting, but it’s not true, according to a new study praised for its methodology.

Low vitamin D status does not increase the risk of corona infection, according to a new U.S. study. However, if influencing factors such as age, gender, ethnicity, body mass index, blood pressure, smoking status and place of residence are included, there is no connection whatsoever.

People with comparatively low vitamin D levels therefore have no higher risk of contracting Sars-CoV-2 than people with an optimal supply.

Not only vitamin D level must be considered
The scientists led by Yonghong Li from the U.S. laboratory company Quest Diagnostics in San Juan Capistrano (U.S. state of California) had analyzed data from the Employee Health Program with annual screenings from 2019 and 2020. A total of 18,148 people between the ages of 37 and 56 were included in the study, about two-thirds of them women. Before the pandemic began, about 60 percent of those screened had a vitamin D level of less than 30 nanograms per milliliter (ng/ml), according to the study. Another 25 percent had an even lower level (less than 20 ng/ml).

Antibodies to Sars-CoV-2 were detected in about five percent of the subjects (900) during the study period. To be sure, the employees and relatives who tested positive had lower vitamin D levels on average than those who tested negative. However, when other factors that markedly influence corona risks were taken into account, no significant association emerged. For example, significantly overweight people (BMI of 30 or more), men and women with hypertension, smokers, and employees and their partners without a college degree were more likely to be vitamin D deficient on average.

No conclusion on correlation of vitamin D and severity of covid 19 progression
According to the authors, one of the limitations of the new analysis is that not all corona infections can be detected via antibodies – among other things because these fade after a certain time. The study does not make a statement about the severity of covid-19 disease as a function of vitamin D status. This was previously investigated by several studies. These suggest the negative influence of low vitamin D levels on the severity of the course of covid-19 disease.

Commenting on the study in Jama Open Network, U.S. health expert Michael Polis praised the methodology of the analysis. “This study shows that one well-designed, appropriately sized observational study can provide more definitive evidence than multiple smaller, poorly designed studies.”

Body can make vitamin D on its own
Vitamin D is the umbrella term for a group of fat-soluble vitamins. Unlike other vitamins, the body can make vitamin D itself – through sunlight, or more precisely UV-B radiation of certain wavelengths. However, recommendations to take vitamin D supplements have been making the rounds on the Internet for quite some time – currently often justified with references to the fact that an infection with the coronavirus or a severe course of a Covid 19 disease could be prevented in this way.

So far, there is no scientifically proven evidence for this. Authorities such as the German Federal Institute for Risk Assessment (BfR) repeatedly warn of the health risks of taking vitamin D supplements on their own, especially those with higher doses. If vitamin D levels in the body are constantly too high, there is a risk of health problems such as the formation of kidney stones or kidney calcification. Therefore, regular (self-)testing of the vitamin D level is strongly recommended.

Eat fatty fish once or twice a week
According to the BfR, the best way to achieve a good vitamin D supply is through the skin’s own synthesis. In addition, it is recommended to eat fatty sea fish such as herring or salmon once or twice a week. A general vitamin D intake of up to 20 micrograms per day is therefore only to be considered for people who hardly move outdoors. This applies, for example, to nursing home residents.

In general, a sufficient supply of vitamins and minerals is important for the immune function of humans, according to the BfR. To protect against colds and respiratory diseases, a varied diet with plenty of fruit and vegetables rich in vitamins and minerals is therefore generally important.