Research suggests the importance of vitamin D for good health in the context of COVID-19

As the coronavirus disease (COVID-19) pandemic continues to spread globally, proactive measures to reduce the risk of infection are vital as there is still no approved vaccine to block severe acute respiratory syndrome coronavirus 2 (SARS-CoV- 2) nor drugs approved for the safe treatment of COVID-19 disease.

Vitamin D deficiency has been linked to the development of severe COVID-19. Correcting the vitamin D deficiency status can be a good goal in the battle against the pandemic.

A researcher at the UNC Nutrition Research Institute, University of North Carolina, revealed that avoiding vitamin D deficiency can help reduce the risk of severe COVID-19.

Additionally, older, obese, and dark-skinned people are likely to need extra vitamin D, especially during the dark months of winter and spring.

Vitamin D and COVID-19 deficiency

The SARS-CoV-2 outbreak first emerged in the city of Wuhan, China in late December 2019. From there, it has spread to over 191 countries and territories. At present, more than 62.6 million individuals worldwide have been infected, with over 1.45 million lives lost.

The current study published in BMJ Nutrition, prevention and health, highlights the factors that can affect vitamin D status and how these are related to COVID-19.

Recent studies have shown the benefits of vitamin D in fighting respiratory infections. The active metabolite of vitamin D, 1,25-dihydroxyvitamin D (1,25D), is produced in immune cells and triggers the expression of several genes linked to a healthy immune response.

The metabolite is also linked with macrophage maturation and recruitment, increased production of cathelicidin and other antibacterial peptides, and promotion of phagocytosis.

However, in some areas of the world, especially in places above 40 ° latitude and includes the United Kingdom, central and northern Europe, Canada and the northern half of the United States, and similarly some regions of the southern hemisphere, Vitamin D deficiency is a common problem during the winter and spring seasons.

People with low vitamin D levels are more likely to develop respiratory infections. So, in the midst of the coronavirus pandemic, health experts believe increasing vitamin D levels is key to avoiding COVID-19.

Additionally, a recent editorial noted that countries below the latitude of 35 degrees North and across the Southern Hemisphere appear to have lower COVID-19 death rates than countries further north. The study author believes that a lower ability to produce vitamin D in higher northern latitudes alters vitamin D status during the cold season, contributing to high mortality rates.

Key modulators of vitamin D status.

Several factors can influence vitamin D status. First, food intake plays a significant role in determining one’s vitamin D status. Only a few foods, mainly cold-water fatty fish such as sardines, herring, mackerel and salmon, contain naturally significant amounts of vitamin D.

Some doctors recommend vitamin D3 supplementation to increase vitamin D levels in the body. From their diet, most people only get very modest amounts of vitamin D.

Another key modulator of vitamin D status is exposure to ultraviolet B (UVB) light. Most of the vitamin D in the blood comes from exposure of the skin to ultraviolet light with wavelengths between 280 and 313 nm, commonly referred to as ultraviolet B (UVB).

Getting adequate sun exposure will help increase vitamin D levels. However, spending too much time indoors, prolonged cloudiness, severe air pollution, covering the skin with clothing and sunscreen can limit the production of vitamin D in the skin.

Aging can also affect the amount of vitamin D a person has in the body. Older age can lead to a lower level of vitamin D. Older people have progressive skin thinning, decreasing the amount of 7-dehydrocholesterol precursor available for vitamin D conversion.

People who are overweight may also suffer from low vitamin D levels. In one study, scientists found that the resulting decrease in vitamin D status is reversible when excess weight is shed.

Additionally, certain genetic variations can also affect vitamin D status. For example, skin tone can affect the body’s ability to produce vitamin D in the skin. In one study, nearly all non-Hispanic blacks and most Mexican Americans had vitamin D deficiency.

“Now, in the context of the current COVID-19 pandemic, renewed attention is needed to the very high prevalence of severe vitamin D deficiency there and elsewhere,” the researcher concluded in the study.

“Advanced age, obesity, dark skin tone and risk-related genotypes, particularly in combination, are warning signs that should require corrective action, typically with a moderate, personalized dose of supplemental vitamin D.” , he added.

The study author points out that while the preventive potential of vitamin D supplements shouldn’t be overstated, preventing vitamin D deficiency should be a widely shared goal. Because COVID-19 severity has also been associated with low vitamin D levels, it is critical for high-risk people to monitor their vitamin D levels.