. 2019 Jan 16;109(1):197–206. doi: 10.1093/ajcn/nqy233

TABLE 3.

Absolute change from baseline to 12 mo postpartum in tibial and radial bone variables assessed by peripheral quantitative computed tomography in women receiving calcium supplementation or placebo during pregnancy¹

	Time of study			P
Dependent variable and supplement group	Visit 3 (36 wk of pregnancy; n = 53)	Visit 4 (4 mo postpartum; n = 45)	Visit 5 (12 mo postpartum; n = 30)	Group	Time	Group × time²
Tibial distal metaphyseal site (3%), g/cm³
Total vBMD				0.087	NS	NS
Calcium	−0.66 ± 2.13	−2.34 ± 1.53	−1.42 ± 2.19
Placebo	−3.30 ± 1.26	−6.48 ± 1.87	−6.61 ± 2.53
Trabecular vBMD				0.067	NS	0.058
Calcium	−1.41 ± 0.83	−1.05 ± 1.18	0.26 ± 2.07
Placebo	−2.58 ± 1.28	−5.41 ± 1.77	−6.71 ± 2.34
Tibial proximal diaphyseal site (38%), g/cm³
Total vBMD				NS	NS	0.062
Calcium	−3.78 ± 1.84	−4.01 ± 6.07	−0.71 ± 2.04
Placebo	1.15 ± 1.58	1.81 ± 1.54	−1.51 ± 1.67
Cortical vBMD				NS	0.021	0.034
Calcium	−1.33 ± 2.02	4.33 ± 1.49	2.27 ± 1.75
Placebo	0.39 ± 1.36	1.51 ± 1.46	−3.55 ± 2.06
Radial distal metaphyseal site (4%), g/cm³
Total vBMD				NS	NS	NS
Calcium	−5.33 ± 6.38	−2.82 ± 6.62	−10.67 ± 6.34
Placebo	−0.49 ± 4.89	−3.43 ± 6.71	0.77 ± 6.51
Trabecular vBMD				NS	0.087	NS
Calcium	−2.10 ± 1.35	−1.86 ± 1.32	−5.32 ± 1.74
Placebo	−0.62 ± 1.02	−1.20 ± 1.06	−3.42 ± 2.45
Radial proximal diaphyseal site (50%), g/cm³
Total vBMD				NS	NS	0.018
Calcium	−7.01 ± 3.75	−1.74 ± 2.97	6.74 ± 4.89
Placebo	1.04 ± 2.19	0.48 ± 2.85	−4.23 ± 3.69
Cortical vBMD				NS	NS	0.053
Calcium	−6.75 ± 4.60	−0.83 ± 3.12	6.69 ± 5.74
Placebo	−0.52 ± 3.08	0.09 ± 2.73	−7.47 ± 5.01

Values are adjusted means ± SEs. Baseline values are not included in the table because they were adjusted for in the statistical models: values shown represent the change from baseline. Calcium: 1000-mg Ca supplement/d from 16 wk of gestation to delivery. Placebo: placebo daily from 16 wk of gestation to delivery. vBMD, volumetric bone mineral density.

Linear mixed models for longitudinal data were used to derive the P values after adjusting for baseline bone values, serum 25-hydroxyvitamin D, length of breastfeeding (in months), and BMI (in kg/m²).