Table 3.

The pair-wise analysis of the differences in mean 25(OH)D levels between the study groups when controlling for multivitamin use

Group Comparison	Difference between mean 25(OH)D levels (ng/ml)	95% Confidence Limits		p-value
No DM or Ocular Disease vs. No DM with Ocular Disease	2.06	−4.18	8.30	0.893
No DM or Ocular Disease vs. No BDR	7.07	0.50	13.65	0.028
No DM or Ocular Disease vs. NPDR	7.65	1.03	14.27	0.015
No DM or Ocular Disease vs. PDR	9.15	2.57	15.73	0.002
No DM with Ocular Disease vs. No BDR	5.01	−1.44	11.46	0.208
No DM with Ocular Disease vs. NPDR	5.59	−0.91	12.08	0.129
No DM with Ocular Disease vs. PDR	7.09	0.68	13.50	0.022
No BDR vs. NPDR	0.57	−6.26	7.41	0.999
No BDR vs. PDR	2.08	−4.69	8.85	0.916
NPDR vs. PDR	1.51	−5.30	8.31	0.974

No BDR: no background diabetic retinopathy; NPDR: nonproliferative diabetic retinopathy; PDR: proliferative diabetic retinopathy