Table 2.

The association between dietary folate intake and BMD

Dietary folate intake (quintile)	Model 1		Model 2		Model 3		Model 4
	β (95% CI)	P value	β (95% CI)	P value	β (95% CI)	P value	β (95% CI)	P value
Total femur, gm/cm2
Q1	Reference		Reference		Reference		Reference
Q2	0.006 (− 0.003, 0.015)	0.180	− 0.002 (− 0.010, 0.006)	0.636	− 0.002 (− 0.010, 0.006)	0.597	− 0.003 (− 0.010, 0.005)	0.519
Q3	0.032 (0.023, 0.041)	< 0.001	0.009 (0.001, 0.017)	0.024	0.008 (0.000, 0.016)	0.038	0.007 (− 0.001, 0.015)	0.092
Q4	0.046 (0.038, 0.055)	< 0.001	0.008 (− 0.000, 0.016)	0.051	0.011 (0.003, 0.019)	0.010	0.010 (0.002, 0.018)	0.017
P trend		< 0.001		0.011		0.001		0.003
Femoral neck, gm/cm2
Q1	Reference		Reference		Reference		Reference
Q2	0.001 (− 0.008, 0.009)	0.891	− 0.002 (− 0.009, 0.006)	0.681	− 0.002 (− 0.010, 0.005)	0.596	− 0.002 (− 0.010, 0.006)	0.595
Q3	0.022 (0.013, 0.030)	< 0.001	0.007 (− 0.001, 0.014)	0.080	0.005 (− 0.002, 0.013)	0.164	0.004 (− 0.004, 0.012)	0.285
Q4	0.030 (0.022, 0.039)	< 0.001	0.007 (− 0.001, 0.015)	0.071	0.008 (0.001, 0.016)	0.035	0.008 (− 0.000, 0.016)	0.052
P trend		< 0.001		0.022		0.009		0.016
Trochanter, gm/cm2
Q1	Reference				Reference		Reference
Q2	− 0.003 (− 0.011, 0.006)	0.528	− 0.005 (− 0.013, 0.004)	0.285	− 0.004 (− 0.013, 0.004)	0.316	− 0.004 (− 0.013, 0.005)	0.415
Q3	0.012 (0.004, 0.020)	0.005	0.003 (− 0.005, 0.012)	0.448	0.004 (− 0.005, 0.013)	0.354	0.005 (− 0.004, 0.014)	0.296
Q4	0.018 (0.009, 0.026)	< 0.001	0.003 (− 0.006, 0.011)	0.563	0.004 (− 0.005, 0.014)	0.332	0.005 (− 0.004, 0.014)	0.267
P trend		< 0.001		0.276		0.132		0.109
Intertrochanter, gm/cm2
Q1	Reference		Reference		Reference		Reference
Q2	0.006 (− 0.001, 0.013)	0.100	− 0.001 (− 0.008, 0.006)	0.839	− 0.001 (− 0.008, 0.006)	0.763	− 0.002 (− 0.009, 0.005)	0.666
Q3	0.027 (0.020, 0.035)	< 0.001	0.010 (0.003, 0.017)	0.005	0.008 (0.001, 0.015)	0.017	0.007 (− 0.000, 0.014)	0.050
Q4	0.040 (0.033, 0.047)	< 0.001	0.010 (0.003, 0.017)	0.005	0.011 (0.004, 0.018)	0.003	0.011 (0.003, 0.018)	0.004
P trend		< 0.001		0.001	0.000 (0.000, 0.000)	0.000		0.000
Total spine area, gm/cm2
Q1	Reference		Reference		Reference		Reference
Q2	0.005 (− 0.005, 0.016)	0.304	− 0.004 (− 0.014, 0.005)	0.360	− 0.004 (− 0.013, 0.005)	0.365	− 0.005 (− 0.014, 0.004)	0.291
Q3	0.034 (0.024, 0.044)	< 0.001	0.007 (− 0.002, 0.017)	0.140	0.007 (− 0.003, 0.016)	0.165	0.005 (− 0.005, 0.014)	0.320
Q4	0.050 (0.040, 0.060)	< 0.001	0.005 (− 0.005, 0.015)	0.318	0.009 (− 0.001, 0.018)	0.073	0.008 (− 0.002, 0.017)	0.128
P trend		< 0.001		0.117		0.016		0.033

Model 1 Crude model

Model 2 Adjusted for age, sex, race, PIR, and marital status

Model 3 Adjusted for age, sex, race, PIR, marital status, BMI, hypertension, serum cotinine, physical activity, and alcohol use

Model 4 Adjusted for age, sex, race, PIR, marital status, BMI, hypertension, serum cotinine, physical activity, alcohol use, and total vitamin D

MET Metabolic equivalent, BMD Bone mineral density