Table 4.
Serum concentrations of 25(OH)D, adjusted calcium, PTH, total ALP and bone-specific ALP at 3-year follow-up by allocation: overall and by sub-group
| Vitamin D arm: mean value (s.d.) [N] |
Placebo arm: mean value (s.d.) [N] |
Adjusted mean difference (95% CI)(1) |
P | P for interaction |
||
|---|---|---|---|---|---|---|
| 25(OH)D, ng/mL | ||||||
| Overall | 29.8 (9.2) [4078] | 9.7 (5.4) [4047] | 20.1 (19.8 to 20.4) | <0.001 | ||
| By sex | Male | 30.3 (9.3) [2102] | 10.1 (5.5) [2004] | 20.2 (19.7 to 20.6) | <0.001 | 0.73 |
| Female | 29.2 (9.0) [1976] | 9.3 (5.2) [2043] | 20.0 (19.6 to 20.5) | <0.001 | ||
| By baseline 25(OH)D concentration(2) | <10 ng/mL | 29.0 (9.2) [1289] | 9.0 (5.1) [1304] | 20.0 (19.4 to 20.5) | <0.001 | 0.81 |
| ≥10 ng/mL | 30.2 (9.1) [2788] | 10.0 (5.5) [2740] | 20.1 (19.7 to 20.5) | <0.001 | ||
| By calcium intake | <500 mg/day | 30.2 (9.1) [2788] | 10.0 (5.5) [2740] | 20.1 (19.7 to 20.5) | <0.001 | 0.16 |
| ≥500 mg/day | 30.2 (9.1) [2788] | 10.0 (5.5) [2740] | 20. 6 (20.0 to 21.1) | <0.001 | ||
| PTH, pmol/L | ||||||
| Overall | 38.4 (18.4) [50] | 51.1 (30.4) [50] | −13.6 (−23.5 to −3.7) | 0.01 | ||
| By sex | Male | 39.2 (21.0) [23] | 55.0 (32.9) [26] | −11.6 (−24.3 to 1.2) | 0.07 | 0.62 |
| Female | 37.7 (16.2) [27] | 46.8 (27.5) [24] | −10.8 (−21.7 to 0.1) | 0.05 | ||
| By baseline 25(OH)D concentration(2) | <10 ng/mL | 38.4 (11.8) [15] | 60.5 (36.1) [19] | −23.9 (−39.5 to −8.3) | 0.01 | 0.04 |
| ≥10 ng/mL | 38.4 (20.7) [35] | 45.3 (25.2) [31] | −7. 6 (−19.1 to 4.0) | 0.19 | ||
| By calcium intake | <500 mg/day | 38.4 (20.7) [35] | 45.3 (25.2) [31] | −20.1 (−32.5 to −7.7) | 0.00 | 0.03 |
| ≥500 mg/day | 38.4 (20.7) [35] | 45.3 (25.2) [31] | 0.7 (−13.1 to 14.5) | 0.92 | ||
| Adjusted calcium, mmol/L | ||||||
| Overall | 2.3 (0.08) [50] | 2.27 (0.13) [50] | 0.02 (−0.02 to 0.06) | 0.24 | ||
| By sex | Male | 2.31 (0.08) [23] | 2.24 (0.15) [26] | 0.03 (−0.05 to 0.1) | 0.49 | 0.68 |
| Female | 2.3 (0.09) [27] | 2.29 (0.09) [24] | 0.01 (−0.03 to 0.05) | 0.57 | ||
| By baseline 25(OH)D concentration(2) | <10 ng/mL | 2.27 (0.06) [15] | 2.21 (0.16) [19] | 0.1 (0.01 to 0.2) | 0.04 | 0.01 |
| ≥10 ng/mL | 2.32 (0.09) [35] | 2.3 (0.09) [31] | 0 (−0.03 to 0.04) | 0.95 | ||
| By calcium intake | <500 mg/day | 2.32 (0.09) [35] | 2.3 (0.09) [31] | 0.03 (−0.02 to 0.08) | 0.25 | 0.56 |
| ≥500 mg/day | 2.32 (0.09) [35] | 2.3 (0.09) [31] | 0.03 (−0.02 to 0.08) | 0.19 | ||
| Total ALP, U/L | ||||||
| Overall | 308.4 (107.9) [50] | 332.8 (118.7) [50] | −20.1 (−63.9 to 23.7) | 0.36 | ||
| By sex | Male | 342.1 (101.7) [23] | 368.8 (134.6) [26] | −24.4 (−81.2 to 32.4) | 0.39 | 0.97 |
| Female | 279.7 (106.4) [27] | 293.9 (85.3) [24] | −10.8 (−59.1 to 37.5) | 0.65 | ||
| By baseline 25(OH)D concentration(2) | <10 ng/mL | 280.9 (107.4) [15] | 369.9 (155.4) [19] | −38.7 (−132.3 to 54.8) | 0.40 | 0.03 |
| ≥10 ng/mL | 320.2 (107. 5) [35] | 310.1 (84.3) [31] | 13.4 (−30.6 to 57.4) | 0.54 | ||
| By calcium intake | <500 mg/day | 320.2 (107.5) [35] | 310.1 (84.3) [31] | −48.1 (−104.7 to 8.6) | 0.09 | 0.10 |
| ≥500 mg/day | 320.2 (107.5) [35] | 310.1 (84.3) [31] | 38.9 (−41.9 to 119.8) | 0.33 | ||
| Bone-specific ALP, U/L | ||||||
| Overall | 31.5 (10.7) [50] | 30.9 (12.8) [50] | −0.2 (−4.8 to 4.4) | 0.93 | ||
| By sex | Boys | 34.7 (9.6) [23] | 35.2 (14.9) [26] | −5.4 (−12.2 to 1.4) | 0.12 | 0.38 |
| Girls | 28.8 (10.9) [27] | 26.3 (8.0) [24] | 2.7 (−1.9 to 7.3) | 0.24 | ||
| By baseline 25(OH)D concentration(2) | <10 ng/mL | 27.6 (11.0) [15] | 34.4 (17.6) [19] | −4.8 (−12.7 to 3.1) | 0.22 | 0.04 |
| ≥10 ng/mL | 33.2 (10.2) [35] | 28.8 (8.4) [31] | 3.9 (−0.7 to 8.5) | 0.09 | ||
| By calcium intake | <500 mg/day | 33.2 (10.2) [35] | 28.9 (8.4) [31] | −4.3 (−10.7 to 2.0) | 0.17 | 0.02 |
| ≥500 mg/day | 33.2 (10.2) [35] | 28.8 (8.4) [31] | 8.9 (1.5 to 16.4) | 0.02 | ||
Abbreviations: 25(OH)D3, 25-hydroxyvitamin D3. ALP, alkaline phosphatase. N, number. QUS, quantitative ultrasound. S.d., standard deviation.
1,
adjusted for baseline value and school of attendance.
2,
deseasonalized values.