Baseline characteristics for study participants by supplementation group*
| Characteristics | Vitamin D (25 µg) N=84 | Vitamin D (10 µg) N=85 | Placebo N=82 |
|---|---|---|---|
| Age (years) | 36 (8.2) | 37 (7.6) | 39 (7.6) |
| Sex (n, %) | |||
| Male | 26 (31) | 24 (28) | 19 (23) |
| Female | 58 (69) | 61 (72) | 63 (77) |
| Regional origin (n, %) | |||
| South Asia | 31 (37) | 31 (36) | 33 (40) |
| Middle East and North Africa | 15 (18) | 9 (11) | 12 (15) |
| Sub-Saharan Africa | 38 (45) | 45 (53) | 37 (45) |
| Years lived in Norway (mean, range) | 13.3 (1–29) | 13.2 (1–35) | 13.6 (2–33) |
| Level of education, years (n, %) | |||
| ≤10 | 34 (40) | 36 (42) | 33 (40) |
| 11–13 | 30 (36) | 31 (37) | 34 (42) |
| ≥14 | 20 (24) | 18 (21) | 15 (18) |
| S-25(OH)D (nmol/L) | 26.9 (16.5) | 29.8 (20.6) | 30.1 (18.9) |
| HbA1c (%)† | 5.6 (0.65) | 5.6 (0.51) | 5.6 (0.43) |
| Fructosamine (µmol/L) | 251 (50.5) | 248 (35.9) | 245 (30.1) |
| Total cholesterol (mmol/L) | 4.8 (0.79) | 4.9 (0.82) | 4.9 (0.90) |
| HDL-cholesterol (mmol/L) | 1.4 (0.31) | 1.4 (0.31) | 1.4 (0.32) |
| LDL-cholesterol (mmol/L) | 3.3 (0.85) | 3.3 (0.88) | 3.4 (0.86) |
| Triglycerides (mmol/L) | 1.6 (0.91) | 1.5 (1.2) | 1.6 (1.13) |
| BMI (kg/m2) | 26.9 (5.2) | 27.5 (5.2) | 27.8 (5.0) |
*Data are mean (SD) unless specified otherwise.
†N=246. Thirty-seven participants did not come back to follow-up; 11 in placebo, 16 in the 10 µg group, and 10 in the 25 µg group. The baseline characteristics of these were not different from those who completed the study.
BMI, body mass index; HbA1c, glycated hemoglobin; HDL, high-density lipoprotein; LDL, low-density lipoprotein; S-25(OH)D, serum 25-hydroxyvitamin D.