When? September.
By who? Cordoba University in Spain.
What have scientists studied? 50 Covid-19 hospital patients with Covid-19 received vitamin D. Their health outcomes were compared with 26 volunteers in a control group who did not receive the tablets.
What have they found? Only one of the 50 patients required intensive care and no one died. Half of the 26 virus patients who did not take vitamin D were later admitted to intensive care and two died.
What were the limitations of the study? Small pool of volunteers. The patients’ vitamin D levels were not checked before admission. Comorbidity was not taken into account.
When? September.
By who? University of Chicago.
What have scientists studied? The vitamin D levels of 500 Americans were tested. Researchers then compared the number of volunteers with the number of coronavirus contracted.
What have they found? 60 percent higher percentages of Covid-19 among people with low levels of the ‘sunshine vitamin’.
What were the limitations of the study?
Researchers have not checked for other constituent factors. It is unclear whether volunteers were vitamin D deficient at the time of their coronavirus tests. People’s age, work and place of residence – factors that greatly increase the risk of infection with the virus – were not taken into account.
When? September.
By who? Tehran University, in Iran, and Boston University.
What have scientists studied? Analyzed data from 235 hospital patients with Covid-19.
What have they found? Patients who had enough vitamin D – of 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 had a lot of the nutrient also had less inflammation – often a deadly side effect of Covid-19.
What were the limitations of the study? Disturbing factors such as smoking and socioeconomic status have not been recorded for all patients and can influence the severity of the disease.
When? July.
By who? Tel Aviv University, Israel.
What have scientists studied? In 782 people who tested positive for the coronavirus, their vitamin D levels were assessed afterwards before infection and compared with healthy people.
What have they found? People with vitamin D levels less than 30 ng / ml – optimal – were 45 percent more likely to test positive and 95 percent more likely to be hospitalized.
What were the limitations of the study? I have not looked at the underlying health conditions and have not checked vitamin D levels at the time of infection.
When? June.
By who? Free University of Brussels.
What have scientists studied? Vitamin D levels compared in nearly 200 Covid-19 hospital patients with a control group of more than 2,000 healthy people.
What have they found? Men admitted to hospital with the infection were significantly more likely to have a vitamin D deficiency than healthy men of the same age. The deficit rate was 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 that when people develop serious illness, vitamin D levels in the blood drop, which the study did not take into account. This suggests that it is the disease that in this study leads to lower vitamin D levels in the blood, not the other way around.
When? June.
By who? Inha University in Incheon, South Korea.
What have scientists studied? 50 hospital patients with Covid-19 were monitored for levels of all vital vitamins and compared to a control group.
What have they found? 76 percent of them were deficient in vitamin D and severe vitamin D deficiency (<10 ng / dl) was found in 24 percent of the Covid-19 patients and only 7 percent in the control group.
What were the limitations of the study?
Small sample size and researchers never stated that vitamin levels dropped when they got sick.
When? June.
By who?. Independent Scientists in Indonesia.
What have scientists studied? Controlled Vitamin D Levels in 780 Covid-19 Hospitalized Patients.
What have they found? Almost 99% of the deceased patients had a vitamin D deficiency. Of the patients with a vitamin D level higher than 30 ng / ml – considered optimal – only percent died.
What were the limitations of the study? It was not peer-reviewed by fellow scientists, a process that often reveals flaws in studies.
When? May.
By who? University of Glasgow.
What have scientists studied? Vitamin D levels in 449 people from the UK biobank who had confirmed Covid-19 infection.
What have they found? Vitamin D deficiency was associated with an increased risk of infection – but not after adjusting for con-founders such as ethnicity. It led the team to conclude that their “findings do not support a possible association between vitamin D levels and the risk of Covid-19 infection.”
What were the limitations of the study? Vitamin D levels were taken 10 to 14 years in advance.
When? May.
By who? University of East Anglia.
What have scientists studied? The mean levels of vitamin D in populations of 20 European countries were compared with the Covid-19 infection and mortality rates at the time.
What have they found? The mean vitamin D content in each country was ‘strongly associated’ with higher levels of Covid-19 cases and deaths. The authors said at the time, “The population most vulnerable to Covid-19 is also the one most deficient in vitamin D.”
What were the limitations of the study? The number of cases in each country was influenced by the number of tests performed and the different measures each country took to prevent the spread of the infection. And it only looked at correlation, not causality.
When? May.
By who? Northwestern University.
What have scientists studied? Crackled data from dozens of studies around the world that included vitamin D levels among Covid-19 patients.
What have they found? Patients with a severe deficiency are twice as likely to have serious complications and death.
What were the limitations of the study? Cases and deaths in each country were affected by the number of tests performed.