Table 2.

Comparison of serum vitamin D levels between the Non-DSPN and DSPN groups.

Variable	Total (n = 569)	Non-DSPN (n = 148)	DSPN (n = 421)	Statistic	P
25(OH)D2, ng/mL	0.79 (0.58–1.21)	0.75 (0.58–1.17)	0.80 (0.58–1.21)	Z = -0.461	0.645
25(OH)D3, ng/mL	25.04 ± 6.41	31.19 ± 5.70	22.88 ± 5.11	t = 16.483	<0.001
25(OH)D, ng/mL	26.12 ± 6.50	32.31 ± 5.97	23.95 ± 5.14	t = 16.302	<0.001

Data are presented as mean ± standard deviation, median (interquartile range), as appropriate. 25(OH)D, 25-hydroxyvitamin D; DSPN, distal symmetric polyneuropathy.