Table 1.

Subject characteristics by supplementation arma

Vitamin D3 dose assignment (IU/d)
CharacteristicPlacebo (n = 81)1,000 (n = 81)2,000 (n = 83)4,000 (n = 83)Pb
Median age, years (IQR)50.7 (44.1–58.0)51.1 (43.4–60.1)50.3 (43.5–58.3)51.3 (44.1–59.7)0.98
Sex, No. (%)0.72
 Male27 (33.3)22 (27.2)28 (33.7)29 (34.9)
 Female54 (66.7)59 (72.8)55 (66.3)54 (65.1)
Median BMI, kg/m2 (IQR)31.2 (26.5–35.9)30.5 (27.0–37.5)31.9 (26.2–36.9)31.4 (27.4–35.7)0.82
Inflammatory markers
 IL-6 (pg/mL)2.21 (1.32–3.42)2.38 (1.53–4.02)2.30 (1.19–4.17)2.24 (1.09–3.84)0.71
 IL-10 (pg/mL)0.55 (0.46–0.68)0.51 (0.47–0.58)0.53 (0.48–0.69)0.52 (0.47–0.61)0.31
 sTNF-R2 (pg/mL)2.047.3 (1.631.0–2,670.5)1,984.8 (1,727.2–2,342.9)2,143.2 (1,685.4–2,652.5)2,011.5 (1,713.1–2,513.7)0.93
 CRP (mg/L)2.74 (1.14–4.56)1.95 (0.79–5.02)2.18 (0.60–6.74)2.23 (0.66–5.35)0.88
 25 (OHD) ng/mL15.1 (10.4–23.6)16.2 (11.0–22.7)13.9 (9.5–22.3)15.7 (11.0–23.3)0.63
Smoking status, No. (%)0.26
 Never33 (40.7)36 (44.4)33 (39.8)44 (53.0)
 Past20 (24.7)16 (19.8)27 (32.5)20 (24.1)
 Current28 (34.6)29 (35.8)23 (27.7)19 (22.9)
Frequency of exercise, days per weekc, median (IQR)3.0 (0.5–5.0)3.0 (1.0–5.0)3.0 (0–5.0)3.0 (0–5.0)0.99
Dietary vitamin D intake, median (IQR)
 Baseline (n = 328)147.3 (71.4–262.8)162.5 (92.6–295.5)144.0 (58.0–265.1)198.1 (83.2–306.4)0.41
Regular multivitamin used, No. (%)10 (12)18 (22)15 (18)22 (27)0.16
Regular vitamin D supplement used, No. (%)8 (10)6 (8)2 (2)8 (10)0.45
Postmenopausal hormone use, No. (%)e0001 (0.5)0.72
Yes
Regular calcium supplement usef, No. (%)7 (8.7)9 (11.1)7 (8.4)9 (10.8)0.49
Regular aspirin useg, No. (%)4 (4.9)10 (12.3)5 (6.0)8 (9.6)0.23
Regular NSAID useh, No. (%)6 (7.4)10 (12.3)10 (12.0)7 (8.4)0.73
Regular acetaminophen useg, No. (%)6 (7.4)6 (7.4)5 (6.0)5 (6.0)0.96
Marital status, married, No. (%)23 (28.4)30 (37.0)23 (27.7)24 (28.9)0.58
Median household income, No. (%)0.92
 <$10,00033 (40.8)23 (28.4)27 (32.5)27 (32.5)
 $10,000–19,99915 (18.5)17 (21.0)17 (20.5)17 (20.5)
 $20,000–29,99911 (13.6)10 (12.3)16 (19.3)10 (12.0)
 $30,000–39,9994 (4.9)9 (11.1)4 (4.8)9 (10.8)
 $40,000–49,9994 (4.9)5 (6.2)4 (4.8)4 (4.8)
 ≥$50,0009 (11.1)11 (13.6)11 (13.3)11 (13.3)
History of canceri, No. (%)6 (7.4)03 (3.6)15 (4.6)0.032
History of hypertension, No. (%)35 (43.2)35 (43.2)36 (43.3)35 (42.1)0.99

Abbreviations: IQR, interquartile range; No., number; NSAID, non-steroidal anti-inflammatory drug.

  • aData are No. (%) unless otherwise indicated. The numbers do not always sum to group totals due to missing information for some variables.

  • bThe Kruskal–Wallis test was used to calculate P values for continuous variables. All statistical tests were two-sided.

  • cExercise defined as moderate to vigorous physical activity for at least 30 minutes, resulting in a faster-than-normal heart rate, sweating, and deep breathing.

  • dRefers to intake during preceding month.

  • ePercentages calculated from a total of 222 females.

  • fDefined as supplement use for 7 days per week during preceding month.

  • gDefined as 3 or more pills per week during the past week.

  • hDefined as 3 or more pills per week during the past week. Types of NSAIDs included salsalate, diflunisal, ibuprofen, ketoprofen, nabumetone, piroxicam, naproxen, diclofenac, indomethacin, sulindac, tolmetin, etodolac, ketorolac, and oxaprozin.

  • iReported cancers include breast cancer, cervical cancer, uterine cancer, lung cancer, prostate cancer, and sarcoma.