| EXPERIMENTAL STUDIES |
|
|
|
|
|
|
|
| Entrenas Castillo M et al (20) |
Spain |
RCT |
76 |
1 |
S,M |
YES |
Positive association. In the treatment group, 2% required admission to the ICU, in the control group 50% |
| Murai IH et al (21) |
Brazil |
DB RCT |
240 |
2 |
S,M |
NO |
No association. Increased 25(OH) D levels in severe COVID patients, did not reduce hospital length of stay or any other relevant outcomes compared to placebo |
| Rastogi A et al (22) |
India |
RCT |
40 |
1 |
/ |
YES |
Positive association. With vitamin D supplementation more COVID patients turned COVID-19 PCR test negative with significant decrease in fibrinogen |
| Annweiler G et al (23) |
France |
QES |
77 |
1 |
S,M |
YES |
Positive association. Regular bolus vitamin D supplementation was associated with less severe COVID-19 and better survival in frail elderly nursing home residents |
| OBSERVATIONAL STUDIES |
|
|
|
|
|
|
|
| De Smet D et al (24) |
Belgium |
ROCS |
186 |
1 |
S,M |
YES |
Positive association. Vitamin D deficiency is correlated with the risk for hospitalization for COVID-19 pneumonia and predisposes to more advanced radiological disease stages |
| Jain A et al (25) |
India |
ROCS |
154 |
1 |
/ |
YES |
Positive association. Vitamin D deficiency in COVID-19 asymptomatic group 32.96% and 96.82% in symptomatic group |
| Merzon E et al (26) |
Israel |
ROCS |
14000 |
/ |
S,I |
YES |
Positive association. The results demonstrated that low vitamin D levels are an independent risk factor for COVID-19 infection and hospitalization due to COVID-19 |
| Israel A et al (27) |
Israel |
ROCS |
576455 |
/ |
I |
YES |
Positive association. Highly significant correlation between prevalence of vitamin D deficiency and COVID-19 incidence |
| Meltzer DO et al (28) |
USA |
ROCS |
489 |
/ |
I |
YES |
Positive association. The relative risk of testing positive for COVID-19 was 1.77 times greater for patients with deficient vitamin D status compared with patients with sufficient vitamin D status before disease |
| Kaufman HW et al (29) |
USA |
ROCS |
190000 |
50 |
I |
YES |
Positive association. The SARS-CoV-2 positivity rate was higher in patients with 25(OH)D deficiency |
| Hastie CE et al (30) |
UK |
ROCS |
502624 |
/ |
I |
NO |
No association. Pre-infection blood samples did not support the vitamin D and the SARS-CoV-2 link |
| Daneshkhah A et al (31) |
USA |
ROCS |
4526 |
6 |
I |
NO |
Positive association. Vitamin D status of a country’s elderly population was associated with the number of severe cases of Covid-19 in that country |
| Hernandez et al (32) |
Spain |
ROCS |
413 |
1 |
S |
YES |
Positive association. 25(OH)D levels are lower in hospitalized COVID-19 patients than in population |
| Fasano et al (33) |
Italy |
ROCS |
2693 |
1 |
S |
YES |
Positive association. Vitamin D supplementation was protective for developing COVID-19 in patient with Parkinson disease |
| Maghbooli Z et al (34) |
Iran |
ROCS |
235 |
1 |
S |
YES |
Positive association between sufficient vitamin D levels and the reduction in clinical severity for COVID-19 |
| D’Avolio A et al (35) |
Swizerland |
ROCS |
107 |
1 |
I |
YES |
Positive association. Significantly lower 25(OH)D levels were found in PCR-positive for SARS-CoV-2 patients compared with negative patients |
| Carpagnano GE et al (36) |
Italy |
ROCS |
42 |
1 |
S,M |
YES |
Positive association. Significantly higher mortality rate among patients with vitamin D deficiency in the ICU |
| Baktash V et al (37) |
UK |
ROCS |
105 |
1 |
S,M |
YES |
Positive association. Patients with vitamin D deficiency and COVID-19 may demonstrate worse morbidity outcomes |
| Mardani Ret al (38) |
Iran |
ROCS |
123 |
1 |
I |
YES |
Positive association. Angiotensin-converting enzyme (ACE) concentration showed a higher quantity among individuals with COVID-19 with insufficient vitamin D concentration |
| Radujkovic A et al (39) |
Germany |
ROCS |
185 |
1 |
S,M |
YES |
Positive association. Vitamin D deficiency was associated with higher risk of invasive mechanical ventilation and death |
| Karahan S et al (40) |
Turkey |
ROCS |
149 |
1 |
S,M |
YES |
Positive association. Mean serum 25(OH)D was significantly lower in patients with severe-critical COVID-19 compared with moderate COVID-19 |
| Faniyi AA (41) |
UK |
ROCS |
392 |
1 |
I |
YES |
Positive association. UK health professionals with vitamin D deficiency were more likely to be seropositive for COVID-19 antibodies |
