Table 3.
Effect of vitamin D and placebo treatment on serum 25-OHD concentration in evaluable subjects categorized by vitamin D status at baseline
| Category of baseline 25-OHD serum concentration | na | 25-OHD concentration (ng/ml), mean (sd; maximal value)b |
Change in 25-OHD, mean (sd) |
|||
|---|---|---|---|---|---|---|
| Baseline | wk 4 | wk 12 | Baseline to wk 4 | wk 4 to wk 12 | ||
| Vitamin D treatment group | ||||||
| All vitamin D | 88 | 21.9 (13.3; 100) | 30.8 (15.1; 104) | 35.9 (19.1; 144) | 9.0 (8.6)c | 5.1 (8.3)c |
| Deficient (<12 ng/ml) | 18 | 9.3 (2.2; 12) | 19.3 (5.3; 31) | 27.1 (6.7; 42) | 10.0 (5.3)c | 7.7 (4.9)c |
| Insufficient (12–<20 ng/ml) | 28 | 15.9 (2.3; 20) | 26.5 (9.1; 64) | 31.9 (14.2; 97) | 10.6 (9.3)c | 5.4 (7.3)c |
| Sufficient (20–50 ng/ml) | 40 | 28.9 (7.3; 46) | 36.2 (12.4; 94) | 40.0 (20.1; 144) | 7.3 (9.3)c | 3.8 (10.0)d |
| Excess (>50 ng/ml) | 2 | 78.3 (30.7; 100) | 88.2 (22.3; 104) | 91.6 (31.0; 114) | 9.9 (8.5) | 3.4 (8.8) |
| 0.065e | 0.019e | |||||
| Placebo treatment group | ||||||
| All placebo | 80 | 21.8 (12.0; 65) | 23.6 (17.7; 144) | 22.2 (12.6; 80) | 1.6 (9.4) | −1.2 (9.5) |
| Deficient (<12 ng/ml) | 13 | 8.0 (2.3; 11) | 9.5 (3.4; 17) | 13.5 (8.2; 30) | 1.7 (3.6) | 4.6 (6.4)d |
| Insufficient (12–<20 ng/ml) | 28 | 15.9 (2.0; 20) | 16.6 (3.4; 23) | 17.3 (5.4; 28) | 0.7 (3.1) | 0.8 (4.9) |
| Sufficient (20–50 ng/ml) | 36 | 28.7 (6.7; 46) | 28.8 (8.0; 58) | 25.8 (8.9; 48) | 0.1 (3.4) | −3.0 (6.1)c |
| Excess (>50 ng/ml) | 3 | 60.0 (5.6; 65) | 87.9 (49.4; 144) | 66.2 (12.0; 80) | 27.9 (44.4) | −21.7 (37.4) |
| 0.302e | 0.001e | |||||
a
Number with values for 25-OHD at both baseline and wk 4.
b
Mean (sd; maximal 25-OHD in participants in each category).
c
P value <0.001 for change in 25-OHD concentration between visits by Wilcoxon signed rank test.
d
P value >0.01 and <0.05 for change in 25-OHD concentration between visits by Wilcoxon signed rank test.
e
P value for differences of change in 25-OHD serum concentrations from baseline to wk 4, or wk 4 to wk 12, by category of baseline vitamin D serum concentration by Kruskal-Wallis test.