Table 2.
25(OH)D levels in DZ and MZ Chinese adolescent twins (n = 226)a
| DZ and MZ twins | DZ twins | MZ twins | |
|---|---|---|---|
| n | 226 | 107 | 119 |
| 25(OH)D (ng/ml) | 18.0 (9.4) | 18.5 (10.9) | 17.5 (8.9) |
| 25(OH)D tertiles, n (%)b | |||
| Low median = 8.8 ng/ml (range, 4.3–14.2 ng/ml) | 75 (33.2) | 34 (31.8) | 41 (34.5) |
| Middle median = 16.3 ng/ml (range, 10.1–23.0 ng/ml) | 75 (33.2) | 35 (32.7) | 40 (33.6) |
| High median = 26.9 ng/ml (range, 18.7–52.7 ng/ml) | 76 (33.6) | 38 (35.5) | 38 (31.9) |
| 25(OH)D <32 ng/ml, n (%) | 204 (90.3) | 96 (89.7) | 108 (90.8) |
a
Sample restricted to Tanner stages III and IV; five DZ pairs had only one twin; three MZ pairs had only one twin.
b
Tertiles are Tanner stage independent.