TABLE 4.
Levels of total 25(OH)D, DBP, and free and bioavailable 25(OH)D among COVID-19 patients1
| Variable | Alive | Deceased | P value |
|---|---|---|---|
| 25(OH)D, nmol/L, median (IQR) | 43.0 (41.0) | 39.5 (48.5) | 0.11 |
| 25(OH)D deficiency < 50 nmol/L, n (%) | 204 (56.7%) | 71 (63.4%) | 0.15 |
| 25(OH)D by categories | — | — | 0.04 |
| <25 nmol/L, n (%) | 85 (23.6%) | 33 (29.5%) | |
| 25–49 nmol/L, n (%) | 119 (33.1%) | 38 (33.9%) | |
| 50–74 nmol/L, n (%) | 99 (27.4%) | 16 (14.3%) | |
| 75–99 nmol/L, n (%) | 47 (13.0%) | 17 (15.2%) | |
| >100 nmol/L, n (%) | 10 (2.8%) | 8 (7.4%) | |
| Free 25(OH)D, pmol/L, median (IQR) | 3.31 (3.93) | 3.73 (4.92) | 0.28 |
| Free 25(OH)D by quintile categories | — | — | 0.32 |
| 0–1.55 pmol/L, n (%) | 66 (20.4%) | 19 (21.1%) | |
| 1.56–2.68 pmol/L, n (%) | 68 (21.0%) | 12 (13.3%) | |
| 2.69–4.10 pmol/L, n (%) | 67 (20.7%) | 18 (20.0%) | |
| 4.11–6.11 pmol/L, n (%) | 64 (19.8%) | 17 (18.9%) | |
| >6.11 pmol/L, n (%) | 59 (18.2%) | 24 (26.7%) | |
| Bioavailable 25(OH)D, nmol/L, median (IQR) | 1.07 (1.26) | 1.01 (1.34) | 0.81 |
| Bioavailable 25(OH)D by quintile categories | — | — | 0.39 |
| 0–0.459 nmol/L, n (%) | 62 (19.1%) | 20 (22.2%) | |
| 0.46–0.81 nmol/L, n (%) | 70 (21.6%) | 12 (13.3%) | |
| 0.82–1.3 nmol/L, n (%) | 64 (19.8%) | 23 (25.6%) | |
| 1.31–2.037 nmol/L, n (%) | 64 (19.8%) | 16 (18.9%) | |
| >2.038 pmol/L, n (%) | 64 (19.8%) | 19 (21.1%) | |
| DBP, mg/L, median (IQR) | 858 (707.8) | 707 (441.0) | 0.005 |
| DBP by quintile categories | — | — | 0.003 |
| 0–579.9 mg/L | 66 (20.3%) | 21 (22.3%) | |
| 580–733.6 mg/L | 69 (21.2%) | 16 (17.0%) | |
| 733.61–960.4 mg/L | 51 (15.7%) | 30 (31.2%) | |
| 960.41–1615 mg/L | 74 (22.8%) | 10 (11.9%) | |
| >1615 mg/L | 65 (20.0%) | 17 (18.1%) |
1
Note that sufficient sera for DBP, and hence free and bioavailable 25(OH)D, were only available for 325/360 (90.3%) of those who were alive and 94/112 (84%) of those who were deceased. A univariate analysis was performed using a chi-squared goodness-of-fit test. Categorical data are represented as counts and percentages and continuous variables as medians and IQRs. Levels of total 25(OH)D were categorized based on published definitions of adequacy and free 25(OH)D; bioavailable 25(OH)D and DBP were categorized as quintiles. COVID-19, coronavirus disease 2019; DBP, vitamin D–binding protein; 25(OH)D, 25-hydroxyvitamin D.