Table 6.

Hip Fracture (Fx) and Association With Quartiles of 25OHD or 1,25(OH)₂D(HR, 95% CI) (n =739)

	Fx (n)	Base modela	Model 2b	Model 3c	Model 4d
25OHD (ng/mL)
Per SD increase in vitamin D		0.69 (0.52, 0.91)e	0.69 (0.52, 0.93)f	0.75 (0.54, 1.02)	0.69 (0.51, 0.93)f
Q1 (3.13–20.90)	44	Referent	Referent	Referent	Referent
Q2 (20.91–25.90)	13	0.38 (0.20, 0.72)	0.38 (0.20, 0.73)	0.41 (0.21, 0.78)	0.38 (0.20, 0.72)
Q3 (26.00–31.00)	15	0.69 (0.37, 1.26)	0.67 (0.36, 1.27)	0.72 (0.37, 1.39)	0.67 (0.36, 1.27)
Q4 (31.10–55.80)	8	0.45 (0.21, 1.00)	0.53 (0.23, 1.22)	0.55 (0.23, 1.31)	0.52 (0.23, 1.21)
p for trend		0.04	0.07	0.17	0.07
Q2, Q3, Q4		Referent	Referent	Referent	Referent
Q1		2.05 (1.28,3.29)f	2.01 (1.24,3.26)f	1.86 (1.14,3.05)e	2.03 (1.25,3.29)f
1,25(OH)2D (pg/mL)
Per SD increase in vitamin D		0.86 (0.66, 1.13)	0.74 (0.56, 1.00)f	0.82 (0.60, 1.12)	0.74 (0.56, 1.00)f
Q1 (8.70–51.60)	31	Referent	Referent	Referent	Referent
Q2 (51.70–62.00)	15	0.64 (0.34, 1.22)	0.49 (0.25, 0.95)	0.51 (0.26, 1.00)	0.49 (0.25, 0.94)
Q3 (62.10–75.10)	19	0.77 (0.43, 1.39)	0.51 (0.28, 0.95)	0.55 (0.30, 1.04)	0.50 (0.27, 0.94)
Q4 (75.20–142.00)	16	0.79 (0.42, 1.50)	0.50 (0.25, 1.00)	0.61 (0.30, 1.27)	0.51 (0.26, 1.01)
p for trend		0.47	0.05	0.11	0.05
Q2, Q3, Q4		Referent	Referent	Referent	Referent
Q1		1.37 (0.85, 2.19)	1.99 (1.19,3.33)f	1.80 (1.07,3.04)e	2.01 (1.20,3.36)f

^aBase model adjusted for age, race, site, season, physical activity, height, and weight.

^bModel 2 = Base model adjusted for baseline hip BMD.

^cModel 3 = Model 2 adjusted for other vitamin D measure; that is, the 25OHD association is adjusted for 1,25(OH)₂D and vice

^dModel 4 = Model 2 adjusted for incident falls in the first year of follow-up.

^ep< 0.01.

^fp< 0.05.