Vitamin D is close to being a “miracle vitamin” if taken in the proper quantities. It has long been known that body must have vitamin D to absorb calcium and promote bone growth and that inadequate amounts result in soft bones in children (rickets) and fragile, misshapen bones in adults. 

Deficiency of the fat-soluble vitamin has been linked in some studies to colon, prostate and breast cancer; heart disease; depression, hypertension, osteoporosis, neuromuscular and autoimmune diseases, type -2 diabetes, cognitive decline, infections, influenza and other conditions. 

Naturally present in very few foods, it is produced in the body when ultraviolet rays from sunlight strike the skin and trigger vitamin D synthesis. But since direct sun exposure might also expose you to potentially dangerous levels of cancer-causing UV radiation, doctors recommend  getting vitamin D from supplements (in drops or pill form) instead. 

In particular, the pronounced impact of vitamin D metabolites on the immune system response and on the development of COVID-19 infection by the novel SARS CoV-2 virus has been previously described in a few studies around the world.  

Now, there is a significant finding from Israeli scientists on the pronounced impact of vitamin D metabolites on the immune system response and the new Corona virus. A collaborative group of scientists from the Leumit Health Services (LHS) and the Azrieli Faculty of Medicine of Bar-Ilan University in Ramat Gan (near Tel Aviv) aimed to determine associations of low plasma 25-hydroxyvitamin D [25(OH)D] with the risk of COVID-19 infection and hospitalization. 

Using the real-world data and a group of 782 COVID-19 positive Israeli patients and 7,807 COVID-19 negative patients, the groups identified that low plasma vitamin D level appears to be an independent risk factor for COVID-19 infection and hospitalization. The research was just published under the title “Low plasma 25(OH) vitamin D level is associated with increased risk of COVID‐19 infection: an Israeli population‐based study” in The FEBS Journal, an open-access publication covering molecular, cellular and biochemical life sciences.

The study included 14,000 members of Leumit Health Services who were tested for COVID‐19 infection from February 1 to April 30, 2020 and who had at least one previous blood test for plasma 25(OH)D level.  

“The main finding of our study was the significant association of low plasma vitamin D level with the likelihood of COVID-19 infection among patients who were tested for COVID-19, even after adjustment for age, gender, socio-economic status and chronic, mental and physical disorders,” said Dr. Eugene Merzon, head of the department of managed care and leading researcher of the LHS group.

 “Furthermore, [a] low vitamin D level was associated with the risk of hospitalization due to COVID-19 infection, although this association wasn’t significant after adjustment for other confounders,” he added. “Our finding is in agreement with the results of previous studies in the field. Reduced risk of acute respiratory tract infection following vitamin D supplementation has been reported,” added Dr. Ilan Green, head of the LHS Research Institute.   

“According to our analysis, persons that were COVID-19 positive were older than non-infected persons. Interestingly, the two-peak distributions for age groups were demonstrated to confer increased risk for COVID-19: around ages 25 and 50 years old,” stated Dr. Milana Frenkel-Morgenstern, the leader of the Azrieli Faculty of Medicine research group. “The first peak may be explained by high social-gathering habits at the young age. The peak at age 50 years may be explained by continued social habits, in conjunction with various chronic diseases,” Frenkel-Morgenstern continued. 

“Surprisingly, chronic medical conditions like dementia, cardiovascular disease and chronic lung disease that were considered to be very risky in previous studies were not found as increasing the rate of infection in our study,” noted Prof. Shlomo Vinker, LHS chief medical officer. “However, this finding is highly biased by the severe social contacts restrictions that were imposed on all the population during the COVID-19 outbreak. Therefore, we assume that following Israeli Health Ministry instructions, patients with chronic medical conditions significantly reduced their social contacts. This might indeed minimize the risk of COVID-19 infection in that group of patients,” explained Vinker.

Dr. Dmitry Tworowski and Dr. Alessandro Gorohovski. from the Frenkel-Morgenstern laboratory at Bar-Ilan University’s Azrieli Faculty of Medicine, suggest that the study will have a very significant impact. “The main strength of our study is its being large, real-world, and population-based,” they wrote. Researchers are now planning to evaluate factors connected with mortality due to COVID-19 in Israel. “We are willing to find associations to the COVID-19 clinical outcomes (for example, pre-infection glycemic control of COVID-19 patients) to make the assessment of mortality risk due to COVID-19 infection in Israel,” said Merzon.