Vitamin D Against COVID-19: More Help or a Hype? | Science | Detailed reports on science and technology | DW

It is indisputable Vitamin D It plays a role everywhere in the body and performs important functions. Severe vitamin D deficiency can occur at levels below 12 nanograms per milliliter of blood, leading to severe painful bone deformity known as rickets in infants and young children and osteomalacia in adults. Cause Unfortunately, the scientific consensus ends here.

Where does the shortage begin?

No one knows exactly how much vitamin D a person actually needs. The question of when the deficiency begins will be controversial. However, vitamin D is becoming increasingly popular.

read more: Vitamin D deficiency risk

The number of published studies has increased significantly in recent years, as well as the pseudo-scientific literature on the rising “solar vitamins”. For example, 2019 Research found it Vitamin D is responsible for maintaining skeletal function and is associated with cardiovascular disease, type 2 diabetes, and various types of cancer.

All Rounder

Vitamin D levels in the body go up and down in response to sun exposure. When enough UV light reaches your skin, the body can produce the vitamins themselves. However, the human body only gets about 10-20% of its daily needs from food.

Vitamin D, which we synthesize from sunlight and food, is initially not biologically active. Before the kidneys produce the biologically active form of vitamin known as calcitriol, and release it into the blood, some metabolic processes must precede it.

In addition, many organs have receptors bound by calcitriol precursors. In addition, this substance is also present in the blood.

From this precursor, the organ produces calcitriol itself. Calcitriol is used by the body for a myriad of other processes in the body. Therefore, this form of vitamin D regulates insulin secretion, inhibits tumor growth, promotes red blood cell formation, and promotes macrophage survival and activity. Immune system.

Low Vitamin D, Severe COVID-19 Disease?

Research carried out At Hohenheim University An association has now been established between vitamin D deficiency, certain previous disorders, and severe cases of COVID-19.

Studies show, “There is plenty of evidence that some non-communicable diseases (hypertension, diabetes, cardiovascular disease, metabolic syndrome) are associated with low plasma levels of vitamin D. These comorbidities are often associated. Vitamin D deficiency increases the risk of severe COVID-19 events.”

“This statement is completely correct,” said Martin Fasnacht, Dean of Endocrinology at the University Hospital of Wurzburg. However, he admits it is a pure link, ie “just an observation that these events happen together.

Dr. Fasnacht is very critical of the hype around vitamin D, but he does not deny that vitamins play an important role. However, studies on humans have failed to show that vitamin D has a healing power that is often transmitted.

“If you look closely, the promise of a curative effect of vitamin D administration has not been confirmed so far,” Fasnacht said.

Related versus intervention studies

Many studies on vitamins are related or observational. “Unsurprisingly, these studies can’t prove causality, they just point to correlations,” Fasnacht said. Doctors try to illustrate this with an example:

“Imagine two 80-year-old groups. One group is active and sporting. When you compare them to another group living in a nursing home, the difference in vitamin D levels is dramatic. Life expectancy is also very different.”

However, trying to explain the difference in fitness solely with vitamin D status is too simplistic. “Vitamin D levels are a good measure of how sick somebody is, but not more,” says Fassnacht.

According to Fasnacht, none of the intervention studies conducted to date-especially to investigate the effects of vitamin D on various diseases-was found in previous associations with laboratory studies or putative positive effects of vitamin D. Could not be confirmed.

Need further research

“If you suspect a coronavirus infection, it’s imperative that you check your vitamin D status and quickly correct any possible deficiencies,” says a recommendation from the Hohenheim University paper.

More details: COVID-19: How to boost your immune system with vitamins

“While research is ongoing to find out if vitamin D can help with COVID-19 infection, I personally do not believe this is the case.” Nevertheless, these studies He says it is, of course, useful to implement.

“I don’t want to rule out that there really is a subgroup of people who would benefit from an additional dose of vitamin D,” he says. After all, this has proven to be the case for serious deficits.

Given the research landscape, Fassnacht does not think much about preventative national vitamin D substitutes. “My belief that vitamins help somewhere is very low, but of course I could be wrong.”