Vitamin D plays a crucial role in the immune system and may combat inflammation. These features may make it a key player in the body’s fight against coronavirus.

Rates of vitamin D deficiency are also higher in some of the same groups who have been hardest hit by coronavirus: people of color and elderly people. It’s by no means a causal link, but suggests that vitamin D could play a role in who gets COVI-19, who gets sickest from it, and who is spared altogether.

Boston University’s Dr Michael Holick found in his previous research that people who have enough vitamin D are 54 percent less likely to catch coronavirus in the first place, the Daily Mail reported.

Following on that work, he and his team have found that people who don’t get enough of the vitamin are far more likely to become severely ill, develop sepsis or even die after contracting coronavirus.

Because vitamin D deficiency is common in people with other disease that raise coronavirus risks, it’s impossible to say exactly how many lives would be spared if we all got our daily dose of the sunshine vitamin.

But we know that about 42 percent of the US population is vitamin D deficient. If that rate held true for the more 203,000 Americans who died of coronavirus, perhaps some 85,000 would have fared better with improved vitamin D levels.

‘This study provides direct evidence that vitamin D sufficiency can reduce the complications, including the cytokine storm (release of too many proteins into the blood too quickly) and ultimately death from COVID-19,’ Dr Holick said.

Dr Holick and his colleagues took blood samples from 235 patients admitted to hospitals in Tehran for COVID-19.

Overall, 67 percent of the patients had vitamin D levels below 30 ng/mL.

There isn’t a clear marker for the ideal level of vitamin D, but 30 ng/mL is considered a sufficient. Anything below that is ‘insufficient,’ but won’t necessarily have broad-ranging health consequences, while levels below 20 ng/mL are considered ‘deficient.’

In the US, an estimated 42 percent of people are vitamin D deficient, but the rate varies considerably in different demographics.

About 60 percent of elderly people living in nursing homes, for example, are thought to be vitamin D deficient.

The most likely explanation is that they simply spend too much time indoors.

Sunlight is our primary source of vitamin D.

When we are exposed to ultraviolet (UV) radiation in rays of sunshine, it reacts with cholesterol in our skin, triggering the production of vitamin D.

In an increasingly indoor world, rates of vitamin D deficiency have climbed.

PEOPLE WITH LOW LEVELS OF VITAMIN D FARE WORSE AGAINST COVID-19 BY ALMOST ANY MEASURE

Among the patients in the BU study, those who had sufficient blood levels of vitamin D were less likely to have dangerously low blood-oxygen levels and were more likely to be conscious upon arrival at hospitals.

Patients with low levels of vitamin D were 46 percent more likely to need to be intubated or to develop acute respiratory distress syndrome (ARDS) – the lung failure condition that proves fatal for many COVID-19 patients.

Vitamin D deficient patients also had higher levels of C-reactive protein, a likely early marker of severe COVID-19, and low counts of white blood cells – a bad sign for their immune systems.

Overall, 74 percent of the patients, who ranged in age from 30s to 90s – developed severe COVID-19.

the rate among vitamin D sufficient people was lower: about 64 percent had severe disease.

All of the under-40 patients included in the study survived COVID-19.

But 16.3 percent of those who were 40 or older – 38 people – ultimately died of coronavirus.

That included just 9.7 percent of people with sufficient vitamin D levels, while 20 percent of those who had low levels of the vitamin died.

What’s more, those with particularly high vitamin D levels – 40 ng/mL – were at the lowest risk of death, with just 6.3 percent of that group dying.

HOW VITAMIN D HELPS THE BODY FIGHT INFECTIONS

Vitamin D is a common ingredient in numerous immune system processes.

To name a few: it helps immune cells bind to their target pathogens, it regulates killer T cells, which go after everything from bacteria to cancer and, perhaps most importantly, it helps keep the balance between ‘good’ inflammation, as immune cells flood an infection site, and ‘bad’ inflammation, that runs haywire and starts attacking healthy cells.

Particularly, it moderates cytokines, the immune proteins that whip up into a fatal ‘storm’ in many coronavirus patients.

‘Indeed, the anti-inflammatory role of 1,25(OH)2D’ – the chemical name for the vitamin – ‘could explain the protective role of vitamin D against immune hyper reaction and cytokine storm in a subgroup of patients with severe COVID-19,’ the study authors wrote.

GROUPS HARD HIT BY CORONAVIRUS ALSO HAVE HIGH RATES OF VITAMIN D DEFICIENCY

Vitamin D deficiency is common in groups with chronic conditions including heart disease and obesity, which are also more vulnerable to COVID-19. However, parsing out whether the vitamin deficiency is a factor that leads to these conditions or vice versa is complicated, and scientists are still working toward answers.

The nutrient deficiency is also common in people of color. In fact, at about 76 percent, vitamin D deficiency is nearly twice as common among black Americans than white people in the US.

Higher levels of melanin in the skin of black and brown people make it more difficult for their bodies to absorb the vitamin.

These groups have been hit disproportionately hard by coronavirus, both in terms of cases and deaths.

the sun is a key element to vitamin D production, the BU researchers saw an additional parallel to coronavirus: timing.

‘It is notable that the COVID-19 outbreak began during the winter. In 1981, a “seasonal stimulus: hypothesis had been suggested to explain epidemics of influenza A around the winter solstice. The biology, physiology, and epidemiology of vitamin D point to vitamin D as a likely candidate for the “seasonal stimulus” since the blood levels of 25(OH)D are lowest at the end of the winter,’ the study authors wrote, referring to the last major pandemic the world saw, the Spanish flu.

Mayo Clinic experts recommend getting at least 600 IU of vitamin D a day, whether via sunshine or supplements. It’s generally considered safe to take up to 2,000 IU a day, but anyone with or at risk of kidney disease should not do so, as an overload can harm kidneys, causing stones and other problems.

Taking too much can also elevate calcium levels, cause a host of digestive issues and may lead to bone loss in some cases – and scientists still don’t know what, exactly, is the optimal level of vitamin D, or how much is too much

A study from the University of Bergen (UiB) concludes that people who have suffered from cardiovascular disease, and have a normal intake of vitamin D, reduce their risk of morality as a consequence of the disease by 30 per cent.

“We discovered that the right amount of vitamin D reduces the risk of death substantially. However, too much or too little increase the risk,” says Professor Jutta Dierkes at the Department of Clinical Medicine, UiB, which lead the study.

The study followed as many as 4,000 patients with cardiovascular diseases from year 2000, for a period of 12 years. The average age of the participants was 62 years old at the start of the study, Science Daily reported.

Difficult recommendations

The study showed that it is favourable to have blood values around 42 to 100 nmol/l. If you have higher or lower values, you are at greater risk of dying from cardiovascular disease.

According to Dierkes, it is difficult to give general a recommendation of how much vitamin D supplementation one should take.

“The optimal amount of vitamin D-supplement varies from one person to another. It depends where you live, and what kind of diet you have,” Dierkes points out.

For example, the Nordic countries recommend an intake of 10 microgram per day from all vitamin D-sources, USA recommends 15 micrograms and Germany 20.

“Even if Norwegians receive less sun then the Germans, the Norwegians have more fish in their diet. Fish and cod liver oil are important sources to vitamin D during the winter, in addition to physical activities outdoors during the summer,” Dierkes explains.

Should measure levels

Dierkes advices all who have experienced cardiovascular diseases to measure their levels of vitamin D, so that these can be better regulated, and the need for supplements assessed. This can usually be done by your local doctor.

“It is, however, important to take in account that the levels vary seasonally A measurement in September will not show the same results as in January, in the Nordic countries.”

“The levels in January or February are often lower because of the lack of sunlight, which induces the skin form to vitamin D,” says Jutta Dierkes.

Results of a University of Nebraska Medical Center study published in the Oct. 10 issue of PLOS ONE, found if the standard supplementation of 400 IUs of vitamin D is increased to 800 IUs daily there are reductions in the number of premature and preterm babies with extremely low bone density. Founded in 2006, PLOS ONE is a multidisciplinary, peer-reviewed journal that focuses on sound science and ethics.

Physicians have been prescribing vitamin D in premature and preterm infants in neonatal intensive care units (NICU) to prevent rickets, a disease that causes soft, weak bones in children and is often associated with vitamin D deficiency. In spite of this, a sizeable number of infants still develop rickets, said Ann Anderson Berry, M.D., associate professor in the division of newborn medicine and medical director of the NICU at Nebraska Medicine, UNMC’s clinical partner.

She said current recommendations of vitamin D supplementation for preterm infants span a wide range of doses, even among major medical groups such as the American Academy of Pediatrics, the Institute of Medicine, and the Endocrine Society. And response to vitamin D supplementation and impact on outcomes in preterm infants is not well understood, she said.

The study provided more evidence in regards to bone health and ideal supplementation. The objective was to evaluate changes in vitamin D in the blood over four weeks in two groups of premature infants born between 24 to 32 weeks gestation. Researchers studied 32 infants at doses of 400 or 800 IU/day of vitamin D.

Researchers saw an improvement in bone density and vitamin D levels in the blood at four weeks. They also saw improvement in growth that significantly decreased the risk of infants having very low bone density.

“We are hopeful that neonatologists will consider giving pre-term infants 800 IUs,” Dr. Anderson Berry said. “We know that even with standard vitamin D dosing, we were still seeing a fair number of pre- term infants who suffered from impaired bone health. This is another form of NICU therapy that can help decrease that risk.”

She said the study is one of the first to look at higher dosing of vitamin D in premature infants. Information will be incorporated as a recommended practice for health professionals.