Table 1.
Study Characteristics.
| Author, Date of Publication | Study Design | Treatment | Population, Male/Female Ratio, Mean Age, Baseline Vitamin D Levels (ng/mL) | ||
|---|---|---|---|---|---|
| Intervention | Control | Intervention | Control | ||
| Annweiler [28] Nov-2020 |
non-randomized clinical trial | 80,000 IU oral vitamin D3 plus standard care | standard care | 16 11/5 85 (IQR = 84–89) NA |
32 19/13 88 (IQR = 84–92) NA |
| Sabico [29] Jun-2021 |
randomized controlled trial | 5000 IU oral vitamin D3 | 1,000 IU oral D3 | 36 21/15 46.3 ± 15.2 21.4 ± 1.2 * |
33 13/20 53.5 ± 12.3 25.2 ± 1 * |
| Güven [30] Sep-2021 |
observational | 300,000 IU of vitamin D3 IM | NA | 113 69/44 74 (IQR = 60–81) 6.65 (5.06–9.1) |
62 36/26 74 (IQR = 60–81) 7.14 (5.17–8.21) |
| Nogues [31] Sep-2021 |
prospective | oral 25(OH)D3 (532 μg on day one plus 266μg on day 3, 7, 15, and 30) plus standard care | standard care | 447 264/183 61.81 ± 15.5 13 (IQR = 8–24) |
391 231/160 62.41 ± 17.2 12 (IQR = 8–19) |
| Elamir [32] Sep-2021 |
randomized controlled trial | 0.5 μg 1,25(OH)2D3 daily for 14 days oral plus standard care | standard care | 25 12/13 69 ± 18 NA |
25 13/12 64 ± 16 NA |
| Entrenas-Castillo [33] Oct-2020 |
randomized controlled trial | oral 25(OH)D3 (0.532 mg), oral calcifediol (0.266 mg) on day 3 and 7, and then weekly plus standard care | standard care | 50 27/23 53.14 ± 10.77 NA |
26 18/8 52.77 ± 9.35 NA |
| Alcala-Diaz [34] May-2021 |
retrospective | oral 25(OH)D3 (0.532 mg), then 0.266 mg on day 3 and 7, and then weekly until discharge or ICU admission plus standard care | standard care | 79 42/37 69 ± 15 NA |
458 275/183 67 ± 16 NA |
| Murai [35] Mar-2021 |
randomized controlled trial | single dose of 200,000 IU of oral vitamin D3 | placebo | 119 70/49 56.5 ± 13.8 21.2 ± 10.1 |
118 63/55 56.0 ± 15.0 20.6 ± 8.1 |
| Tan [36] Nov/Dec 2020 |
retrospective | 1000 IU/d oral vitamin D3 and 150 mg/d oral magnesium, and 500 mcg/d oral vitamin B12 | NA | 17 11/6 58.4 ± 7 NA |
26 15/11 64.1 ± 7.9 NA |
| Soliman [37] Sep-2021 |
prospective | vitamin D3 as a single IM (200,000 IU) injection |
placebo | 40 NA 71.30 ± 4.16 10.4 ± 1.3 |
16 NA 70.19 ± 4.57 21.17 ± 3.96 |
| Jevalikar [25] Mar-2021 |
prospective | median total dose of 60,000 IU oral vitamin D3 | NA | 128 NA 45.5 ± 18.2 NA |
40 NA 48.8 ± 14.7 NA |
IU: International Units, IM: intramuscular, d: day, mg: milligrams, μg: micrograms, ng/mL: nanograms per milliliter, IQR: Interquartile Range, NA: not available. * Originally given at nmol/L, but converted here to ng/mL for consistency.