Table 2.
Mean concentration of 25‐OH VitD in analyzed samples at different time intervals
| Day | Non‐vortexed | Vortexed | P * | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Mean ± SD (nmol/L) | Subsequent days to day 0 | Mean ± SD (nmol/L) | Subsequent days to day 0 | ||||||
| Diff. | P | Diff. | P | ||||||
| Bias | % | Bias | % | ||||||
| 0 | 34.12 ± 12.97 | 33.66 ± 12.97 | .118 | ||||||
| 1 | 34.26 ± 13.72 | 0.14 | 0.41 | .654 | 35.10 ± 13.19 | 0.75 | 4.28 | .043 | .003 |
| 2 | 37.02 ± 13.20 | 2.90 | 8.50 | .000 | 35.85 ± 13.01 | 1.50 | 6.51 | .087 | .171 |
| 3 | 35.18 ± 13.29 | 1.06 | 3.11 | .039 | 35.47 ± 13.04 | 1.12 | 5.38 | .039 | .473 |
| 4 | 35.73 ± 12.89 | 1.61 | 4.72 | .000 | 36.65 ± 13.35 | 2.30 | 8.88 | .000 | .037 |
| 5 | 36.54 ± 13.97 | 2.42 | 7.09 | .000 | 34.98 ± 13.17 | 0.63 | 3.92 | .118 | .002 |
| 15 | 36.99 ± 13.22 | 2.87 | 8.41 | .000 | 36.55 ± 13.75 | 2.20 | 8.59 | .004 | .499 |
| 30 | 35.99 ± 12.63 | 1.87 | 5.48 | .000 | 34.05 ± 12.71 | 0.58 | 1.16 | .118 | .025 |
Diff. refers to the mean difference in serum 25‐OH VitD results on subsequent days compared with day 0 with the P value of the corresponding day.
*
P refers to the difference in results between non‐vortexed and vortexed specimens.