Determination of vitamin D and analysis of risk factors for osteoporosis in patients with chronic pain

Table 2 Comparison of the percentage of vitamin D concentration between the study and control groups

Vitamin D level	Study group (n = 184), n (%)	Control group (n = 104), n (%)	c2	P value
< 10	55 (29.9)	1 (1.0)	35.502	0.000
10-20	99 (53.8)	60 (57.7)	0.406	0.524
20-30	25 (13.6)	33 (31.7)	13.600	0.000
≥ 30	5 (2.7)	10 (9.6)	6.404	0.011