. 2018 May 23;148(6):868–875. doi: 10.1093/jn/nxy043

TABLE 4.

Correlations between biochemical markers by stage of pregnancy in adolescents¹

	PTH	1,25(OH)₂D	24,25(OH)₂D	24,25:25	Ca	P_i
25(OH)D
T1	−0.08	0.25	0.92^****	0.38	−0.35	−0.08
T2	0.10	0.17	0.86^****	0.51^****	−0.01	−0.16
T3	−0.20	0.20	0.92^****	0.71^****	0.25	0.06
D	−0.27^*	0.21	0.92^****	0.74^****	NA	NA
PTH
T1		0.17	−0.21	−0.11	−0.23	0.30
T2		0.11	0.03	−0.08	−0.25	−0.16
T3		−0.08	−0.23	−0.14	−0.18	−0.23
D		−0.12	−0.30^*	−0.29^*	NA	NA
1,25(OH)₂D
T1			0.22	0.10	0.05	0.22
T2			0.06	−0.10	−0.14	−0.13
T3			0.15	0.01	0.48^***	0.15
D			0.03	−0.12	NA	NA
24,25(OH)₂D
T1				0.70^***	−0.22	−0.11
T2				0.84^****	−0.04	−0.22
T3				0.89^****	0.10	−0.03
D				0.90^****	NA	NA
24,25:25
T1					0.03	−0.02
T2					−0.03	−0.16
T3					−0.07	−0.13
Ca
T1						0.51^*
T2						0.35^**
T3						0.36^**

¹Each test used 1 data point per participant (earliest available) at each stage of pregnancy, *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001. Ca, total serum calcium; D, delivery (n = 58, except for 25(OH)D n = 62 and PTH n = 56); NA, not available; P_i, total serum phosphorus; T1, trimester 1 (n = 19, except for PTH n = 17); T2, trimester 2 (n = 57, except for PTH n = 52); T3, trimester 3 (not delivery visit) (n = 53, except for PTH, calcium, and phosphorus n = 52); 1,25(OH)₂D, 1,25-dihydroxyvitamin D; 24,25(OH)₂D, 24,25-dihydroxyvitamin D; 24,25:25, the molar ratio of 24,25(OH)₂D to 25(OH)D; 25(OH)D, 25-hydroxyvitamin D.