Table 2.

Correlation matrix of iron indices, vitamin D, oxidative stress, and AKI markers (Pearson correlation)

Variables		Iron parameters									Vitamin D		Oxidative stress				AKI
		1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
Iron parameters	1. Serum iron	1
	2. TSAT	0.232	1
	3. Serum ferritin	.379*	0.052	1
	4. Serum hepcidin	−0.316	0.216	−.667**	1
	5. Hemoglobin	0.197	−.345*	.346*	−0.287	1
	6. Haptoglobin	0.241	−0.008	0.012	−0.205	0.307	1
	7. Serum CPK	0.258	0.124	−.452**	.385*	−.503**	−0.07	1
	8. Serum catalytic iron	.439**	−0.065	.472**	−.856**	0.026	0.188	−0.19	1
	9. Urine catalytic iron	.454**	−0.15	.806**	−.679**	.633**	0.235	−.563**	.517**	1
Vit D	10. 25(OH)D3	−.374*	−0.083	0.304	−0.171	−0.015	−0.24	−.685**	0.123	0.293	1
	11. 1,25(OH)2D3	0.233	0.029	.765**	−.795**	0.027	−0.045	−.498**	.784**	.649**	.481**	1
Oxidative stress	12. Tissue peroxidation	.489**	0.225	0.301	0.045	0.12	0.19	−0.024	0.004	.469**	0.175	0.05	1
	13. Tissue thiol	−0.01	−0.078	−.720**	.489**	0.009	0.076	.569**	−.368*	−.611**	−.647**	−.814**	−0.243	1
	14. Catalase	0.035	−0.149	−.558**	0.195	−0.085	0.038	.658**	−0.074	−.580**	−.734**	−.528**	−.556**	.832**	1
	15. SOD	0.06	−0.146	−0.218	.363*	.635**	0.234	−0.153	−.453**	0.1	−0.138	−.591**	.366*	.494**	0.048	1
AKI	16. Urinary NGAL	.506**	0.142	.699**	−.432**	0.144	0.119	−0.308	.410*	.788**	.401*	.609**	.787**	−.712**	−.780**	−0.074	1

TSA: transferrin saturation; CPK: creatine phosphokinase; Vit D: vitamin D; 25(OH)D3: 25-dihyrdoxyvitamin D3; 1,25(OH)2D3: 1,25-dihydroxyvitamin D3; SOD: superoxide dismutase; NGAL: neutrophil gelatinase-associated lipocalin

*P < 0.05, ** P < 0.01, ***P < 0.001 (2-tailed), Pearson correlation coefficients (n = 36).