Table 4. Pearson correlation coefficients and significance of correlations (P) between iron parametersa (n=940)b.

	Hb	RBC	MCV	MCH	MCHC	RDW	Log(SF)	Log(sTfR)
Boys
Log(SF)	0.25**	0.11*	0.17**	0.19**	0.10**	−0.14**	—	−0.25**
Log(sTfR)	0.16**	0.07	−0.16**	−0.22**	−0.20**	0.09**	−0.25**	—
Girls
Log(SF)	0.35**	0.004*	0.34**	0.41**	0.40**	−0.42**	—	−0.39**
Log(sTfR)	0.21**	0.11	−0.32**	−0.35**	−0.29**	0.35**	−0.39**	—
Total
Log(SF)	0.36**	0.13	0.24**	0.32**	0.32**	−0.31**	—	−0.33**
Log(sTfR)	0.16**	0.07	−0.26**	−0.30**	−0.24**	0.26**	−0.33**	—

Abbreviations: Hb, haemoglobin; MCH, mean corpuscular haemoglobin; MCHC, mean corpuscular haemoglobin concentration; MCV, mean corpuscular volume; RBC, red blood cells; RDW, red cell distribution width; SF, serum ferritin; sTfR, soluble transferrin receptor.

^aAll data were adjusted by a weighing factor to balance the sample according to the theoretical age distribution of the European adolescent population.

^bThe count of subjects (n) are reported in the table as unweighted values.

^*P<0.05; ^**P<0.01 boys versus girls.