Table 1 Demographic characteristics of the elderly Chinese study participants
Men | Women | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
n | 25(OH)D (nmol/l) | Percentage with 25(OH)D levels | P value | n | 25(OH)D (nmol/l) | Percentage with 25(OH)D levels | P value | |||||||
mean | SD | <30 nmol/l | 30–50 nmol/l | >50 nmol/l | mean | SD | <30 nmol/l | 30–50 nmol/l | >50 nmol/l | |||||
Total | 2948 | 63.3 | 25.1 | 7.8 | 26.3 | 65.9 | 3066 | 56.1 | 22.9 | 12 | 32 | 56 | ||
Age group | 0.7021 | 0.2938 | ||||||||||||
60–69 | 1818 | 63.9 | 25.1 | 7.5 | 25.5 | 67 | 1987 | 56.4 | 23.1 | 11.2 | 32.7 | 56.1 | ||
70–79 | 951 | 62.5 | 25 | 8.2 | 27.7 | 64.1 | 878 | 55.4 | 22.4 | 13.7 | 30.2 | 56.2 | ||
80+ | 179 | 61.9 | 24.6 | 8.4 | 27.9 | 63.7 | 201 | 56 | 22.9 | 11.9 | 33.8 | 54.2 | ||
BMI (kg/m2) | 0.7826 | 0.3829 | ||||||||||||
<18.5 | 414 | 62.7 | 25.9 | 6.8 | 30 | 63.3 | 398 | 56.1 | 24.5 | 12.6 | 33.4 | 54 | ||
18.5–24.0 | 1303 | 63.9 | 24.9 | 7.7 | 25 | 67.3 | 1363 | 56.9 | 23.1 | 11.4 | 31.4 | 57.2 | ||
24.0–28.0 | 870 | 63.2 | 25 | 8.2 | 25.4 | 66.4 | 957 | 55.3 | 22.1 | 13 | 31.5 | 55.6 | ||
>28.0 | 361 | 62.2 | 24.9 | 8.6 | 29.1 | 62.3 | 348 | 55 | 21.8 | 10.9 | 34.5 | 54.6 | ||
Ethnicity | 0.006 | 0.2212 | ||||||||||||
Han nationality | 2719 | 63.7 | 25 | 7.3 | 26.2 | 66.5 | 2810 | 56.4 | 23 | 11.8 | 31.6 | 56.6 | ||
Hui nationality | 11 | 71.9 | 24.6 | 9.1 | 0 | 90.9 | 20 | 53.5 | 17.4 | 5 | 50 | 45 | ||
Other nationality | 218 | 57.8 | 25 | 13.8 | 28.9 | 57.3 | 236 | 52.2 | 20.7 | 14.4 | 36 | 49.6 | ||
Regional strata | <0.0001 | 0.0005 | ||||||||||||
Large cities | 701 | 58.2 | 23 | 9.8 | 30.7 | 59.5 | 724 | 55.3 | 22.1 | 10.1 | 37.6 | 52.3 | ||
Small to medium cities | 875 | 65.6 | 26.5 | 6.6 | 25.9 | 67.4 | 885 | 55.8 | 23.5 | 12.2 | 33.7 | 54.1 | ||
General rural areas | 859 | 65.6 | 25.4 | 7.9 | 21.5 | 70.5 | 924 | 57.2 | 23.6 | 14.2 | 26.8 | 59 | ||
Poor rural areas | 513 | 62.4 | 23.8 | 6.8 | 29 | 64.1 | 533 | 55.6 | 21.3 | 10.3 | 30.8 | 58.9 | ||
Vitamin D supplementation | 0.8237 | 0.4676 | ||||||||||||
No | 2940 | 63.3 | 25.1 | 7.8 | 26.3 | 65.9 | 3057 | 56.1 | 22.9 | 12 | 32 | 56 | ||
Yes | 8 | 68.4 | 24.3 | 0 | 25 | 75 | 9 | 51.9 | 14 | 11.1 | 33.3 | 55.6 | ||
Ambient UVB levels (J/m2) | <0.0001 | <0.0001 | ||||||||||||
Low | 953 | 60.1 | 25.2 | 8.1 | 34 | 57.9 | 964 | 51.7 | 21.6 | 13.8 | 39.6 | 46.6 | ||
Medium | 953 | 62.9 | 25.3 | 8.6 | 26.9 | 64.5 | 1045 | 55.7 | 23.1 | 13.4 | 31.5 | 55.1 | ||
High | 1042 | 66.6 | 24.3 | 6.8 | 18.8 | 74.4 | 1057 | 60.5 | 22.9 | 8.9 | 25.6 | 65.5 | ||
Hypertension | 0.5523 | 0.6414 | ||||||||||||
No | 2081 | 63.9 | 25 | 7.5 | 25.9 | 66.6 | 2150 | 55.9 | 22.8 | 12.5 | 31.9 | 55.6 | ||
Yes | 867 | 61.9 | 25.2 | 8.5 | 27.3 | 64.1 | 916 | 56.6 | 22.9 | 10.7 | 32.3 | 57 | ||
Education level | 0.8044 | 0.0779 | ||||||||||||
Illiteracy | 248 | 61.2 | 24.9 | 9.3 | 27 | 63.7 | 254 | 55 | 25.9 | 15.8 | 30.3 | 53.9 | ||
Literate | 2700 | 63.5 | 25.1 | 7.7 | 26.3 | 66.1 | 2812 | 56.2 | 22.6 | 11.6 | 32.2 | 56.2 | ||
Season | 0.1786 | <0.0001 | ||||||||||||
Spring | 125 | 56.1 | 25.1 | 13.6 | 32.8 | 53.6 | 132 | 49.1 | 18.9 | 16.7 | 40.2 | 43.2 | ||
Summer | 382 | 64.1 | 23.9 | 6.3 | 24.9 | 68.8 | 383 | 59 | 21.8 | 7.3 | 28.2 | 64.5 | ||
Autumn | 1943 | 63.8 | 25.5 | 7.5 | 26.4 | 66.1 | 2042 | 56.6 | 23.3 | 11.5 | 32.2 | 56.3 | ||
Winter | 498 | 62.6 | 24.2 | 8.6 | 25.5 | 65.9 | 509 | 53.7 | 22.4 | 16.1 | 32.2 | 51.7 | ||