Table 2. Mean PTH concentrations, dietary calcium intake, and whole body BMD according to quantiles of 25(OH)D in NHANES 2003–2004, stratified by race and ethnicity^a.

	Categories of 25-hydroxyvitamin D (ng/ml)
	>31	30−26	25−21	20−16	15−11	≤10	P valuesb
All race/ethnicity, N (total=4,206)	882	701	844	780	618	381	<0.01
Dietary calcium intake, mg/d	1,001±29	927±28	954±27	831±23	784±25	666±28	<0.01
Serum parathyroid hormone, pg/ml	35±0.9	41±0.7	42±1	44±0.9	49±1	55±2	<0.01
BMD g/cm2	1.03±0.01	1.03±0.01	1.03±0.01	1.03±0.01	1.03±0.01	1.03±0.01	0.79
White, N (total=2,239)	736	477	480	337	152	57
Dietary calcium intake, mg/d	1,007±29	924±29	967±31	853±33	830±47	645±59	<0.01
Serum parathyroid hormone, pg/ml	35±0.9	40±0.7	41±1	44±1	49±2	58±4	<0.01
BMD, g/cm2	1.03±0.01	1.03±0.01	1.03±0.01	1.02±0.01	0.99±0.01	0.96±0.02	<0.01
Mexican-American, N (total=989)	106	162	236	223	183	79
Dietary calcium intake, mg/d	979±69	996±41	985±72	889±68	816±28	819±126	<0.01
Serum parathyroid hormone, pg/ml	37±1	45±2	45±1	49±2	50±2	50±1	<0.01
BMD, g/cm2	1.03±0.01	1.03±0.01	1.03±0.01	1.01±0.01	1.00±0.01	0.99±0.01	<0.01
Black, N (total=978)	40	62	128	220	283	245
Dietary calcium intake, mg/d	715±54	856±90	783±52	698±40	700±45	645±48	0.03
Serum parathyroid hormone, pg/ml	41±4	41±2	42±2	44±1	47±2	54±2	<0.01
BMD, g/cm2	1.08±0.02	1.15±0.03	1.09±0.01	1.09±0.01	1.10±0.01	1.08±0.01	0.21

^aWhole body BMD values from 2005–2006 were unavailable

^bP value from univariate linear regression analyses with 25(OH)D as the dependent variable and either serum PTH, dietary calcium intake, or BMD as the independent variable