Table 1

Selected characteristics of the study participants by serum 25(OH)D levels, National Health and Nutrition Examination Survey (NHANES) 2001 to 2006
Charactersa Normal, n = 6962 Insufficiency, n = 3620 Deficiency, n = 1575 P valueb
Serum 25(OH)D (ng/ml), mean (SE) 28.5 (0.2) 16.1 (0.2) 8.8 (0.1) <0.001
Age (years), mean (SE) 47.0 (0.4) 46.7 (0.4) 46.2 (0.6) <0.001
Male, n (%) 3711 (51.2) 1833 (47.7) 696 (38.4) <0.001
Body mass index (kg/m2), mean (SE) 27.3 (0.1) 29.6 (0.2) 31.5 (0.4) <0.001
Month of blood collection, n (%)
 1 November to 30 April (winter) 2,688 (34.4) 1,980 (50.7) 999 (57.6) <0.001
 1 May to 31 October (summer) 4,274 (65.6) 1,640 (49.3) 676 (42.4)
Education, n (%)
 Less than high school 1,694 (14.8) 1,194 (21.8) 621 (28.5) <0.001
 High school 1,729 (25.3) 872 (26.3) 384 (25.4)
 Greater than high school 3,535 (59.9) 1,550 (51.9) 667 (46.1)
Race/ethnicity, n (%)
 Non-Hispanic Caucasian 4,812 (84.5) 1,390 (59.5) 316 (33.9) <0.001
 Non-Hispanic Black 558 (3.5) 965 (17.0) 906 (44.8)
 Hispanic 1,394 (8.6) 1,091 (16.5) 394 (14.1)
 Others 198 (3.4) 174 (7.1) 59 (7.1)
Family poverty income ratio, n (%)
 <1 929 (9.7) 661 (15.6) 358 (20.0) <0.001
 1 to 4 4,181 (61.5) 2,230 (63.6) 1,031 (65.7)
 ≥5 1,507 (28.8) 516 (20.8) 181 (14.3)
Smoker, n (%)
 Non-smoker 3,407 (49.5) 1,856 (50.0) 869 (50.0) <0.001
 Former smoker 1,914 (24.8) 833 (21.0) 303 (16.3)
 Current smoker 1,637 (25.7) 926 (29.0) 500 (33.8)
Alcohol user, n (%)
 Non-drinker 784 (15.0) 555 (21.5) 293 (24.2) <0.001
 Former drinker 559 (10.3) 382 (14.3) 187 (14.1)
 Current drinker 3,139 (74.8) 1,452 (64.2) 639 (61.7)
Physical activity during the day, n (%)
 Sit and not walk about very much 1,512 (21.2) 960 (27.0) 541 (32.9) <0.001
 Walk a lot 3,584 (50.4) 1,904 (50.5) 857 (49.2)
 Light work 1,276 (20.5) 497 (15.2) 202 (13.9)
 Heavy work 582 (8.0) 254 (7.3) 73 (4.0)
Leisure time physical activity (Metabolic equivalent/h/week), mean (SE) 1,292.4 (52.2) 788.5 (55.6) 674.2 (53.1) <0.001
Users of supplement containing vitamin D (%) 3,258 (47.2) 1,018 (30.4) 202 (12.5) <0.001
Users of supplement containing Ca (%) 3,860 (57.1) 1,380 (42.6) 351 (22.3) <0.001
Users of supplement containing Mg (%) 3,040 (45.1) 1,072 (32.0) 235 (14.9) <0.001
Energy-adjusted nutrient intakesc, mean (SE)
  Protein (g/day) 82.0 (0.5) 80.1 (0.7) 77.8 (1.3) <0.01
  Carbohydrate (g/day) 258.5 (1.4) 262.4 (1.7) 261.6 (2.9) 0.135
  Fat (g/day) 80.7 (0.5) 80.3 (0.6) 81.2 (0.9) 0.93
  Calcium (mg/day) 929.0 (8.4) 805.2 (9.1) 690.3 (13.6) <0.001
  Magnesium (mg/day) 293.1 (2.2) 266.6 (2.9) 252.4 (4.2) <0.001
  Vitamin D (IU/day) 196 (8.0) 160 (8.0) 116 (8.0) <0.001
  Total calcium (mg/day)d 1,168.8 (12.6) 935.4 (12.3) 748.5 (15.9) <0.001
  Total magnesium (mg/day)d 344.2 (3.5) 297.3 (3.2) 262.4 (4.4) <0.001
  Total vitamin D (IU/day)d 376 (8.0) 276 (8.0) 152 (8.0) <0.001

aValues are present as weighted means (SE) and unweighted frequencies (weighted percentages, %).

bRao-Scott χ2 test for categorical data and analysis of variance (ANOVA) test for continuous variables.

cValues are energy-adjusted means (SE).

dTotal calcium, magnesium and vitamin D intake from foods and supplements.

Deng et al.

Deng et al. BMC Medicine 2013 11:187   doi:10.1186/1741-7015-11-187

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