When? September.
By whom? Cordoba University in Spain.
What did the scientists study? 50 hospital patients from Covid-19 with Covid-19 received vitamin D. Their health outcomes were compared with 26 volunteers in a control group who did not receive the pills.
What did they find? Only one of the 50 patients required intensive care and none died. Half of the 26 virus carriers who did not take vitamin D were later admitted to intensive care and two died.
What were the limitations of the study? Small group of volunteers. The patients’ vitamin D levels were not checked before admission. Comorbidities were not considered.
When? September.
By whom? University of Chicago.
What did the scientists study? The vitamin D levels of 500 Americans were tested. The researchers then compared the volunteers’ levels with those who contracted the coronavirus.
What did they find? 60% higher rates of Covid-19 among people with low levels of the ‘sun vitamin’.
What were the limitations of the study?
The researchers did not verify other composition factors. It is not clear whether or not the volunteers were vitamin D deficient at the time of their coronavirus tests. People’s age, employment and place of residence – factors that greatly increase the chances of contracting the virus – were not considered.
When? September.
By whom? Tehran University, Iran, and Boston University.
What did the scientists study? Data analyzed from 235 patients hospitalized with Covid-19.
What did they find? Patients who had enough vitamin D – at least 30 ng / mL – were 51.5 percent less likely to die from the disease. They also had a significantly lower risk of becoming seriously ill or needing ventilation. Patients who received the nutrient in abundance also had less inflammation – usually a deadly side effect of Covid-19.
What were the limitations of the study? Confounding factors, such as smoking and socioeconomic status, have not been recorded for all patients and can impact the severity of the disease.
When? July.
By whom? Tel Aviv University, Israel.
What did the scientists study? 782 people who tested positive for coronavirus had their vitamin D levels before infection assessed retrospectively and compared to healthy people.
What did they find? People with vitamin D levels below 30 ng / ml – ideally – were 45 percent more likely to test positive and 95 percent more likely to be hospitalized.
What were the limitations of the study? He did not observe the underlying health conditions and did not check vitamin D levels at the time of infection.
When? June.
By whom? Free University of Brussels.
What did the scientists study? Vitamin D levels compared in almost 200 patients at Covid-19 hospital with a control group of more than 2,000 healthy people.
What did they find? Men who were hospitalized with the infection were significantly more likely to have vitamin D deficiency than healthy men of the same age. Disability rates were 67 percent in the COVID-19 patient group and 49 percent in the control group. The same was not found for women.
What were the limitations of the study? Independent scientists say vitamin D levels in the blood decrease when people develop serious illnesses, which the study did not take into account. This suggests that it is the disease that is leading to the lowest levels of vitamin D in the blood in this study, and not the other way around.
When? June.
By whom? Inha University in Incheon, South Korea.
What did the scientists study? 50 hospital patients with Covid-19 were checked for levels of all vital vitamins and compared to a control group.
What did they find? 76 percent of them were deficient in vitamin D, and a severe vitamin D deficiency (<10 ng / dl) was found in 24 percent of patients with Covid-19 and only 7 percent in the control group.
What were the limitations of the study?
Small sample and the researchers never explained the drop in vitamin levels when they get sick.
When? June.
By whom?. Independent scientists in Indonesia.
What did the scientists study? Vitamin D levels verified in 780 patients at Covid-19 hospital.
What did they find? Almost 99% of the patients who died had vitamin D deficiency. Of the patients with vitamin D levels above 30 ng / ml – considered ideal – only percent died.
What were the limitations of the study? It has not been reviewed by fellow scientists, a process that often reveals flaws in the studies.
When? May.
By whom? University of Glasgow.
What did the scientists study? Vitamin D levels in 449 people from the UK’s Biobank who confirmed Covid-19 infection.
What did they find? Vitamin D deficiency was associated with an increased risk of infection – but not after adjusting for underlying factors, such as ethnicity. This led the team to conclude that their ‘findings do not support a potential link between vitamin D concentrations and the risk of Covid-19 infection’.
What were the limitations of the study? Vitamin D levels were measured 10 to 14 years in advance.
When? May.
By whom? East Anglia University.
What did the scientists study? Average levels of vitamin D in populations in 20 European countries were compared with the Covid-19 infection and mortality rates at the time.
What did they find? The average level of vitamin D in each country was ‘strongly associated’ with higher levels of Covid-19 cases and deaths. The authors said at the time: ‘The most vulnerable group of the population for Covid-19 is also the one with the highest vitamin D deficit.’
What were the limitations of the study? The number of cases in each country was affected by the number of tests performed, as well as the different measures taken by each country to prevent the spread of the infection. And he looked only at correlation, not causality.
When? May.
By whom? Northwestern University.
What did the scientists study? Data processed from dozens of studies worldwide that included vitamin D levels among patients with Covid-19.
What did they find? Patients with severe disabilities are twice as likely to suffer serious complications and die.
What were the limitations of the study? The cases and deaths in each country were affected by the number of tests performed.