The concentrations of serum copper were determined as an indicator of corporal status of Cu and its relation to aging in 93 institutionalized elderly subjects (24 men and 69 women) in Granada (Spain). We found that aging does not affect serum Cu levels in the two age groups included in the study: Group I < 80 years and Group II > or = 80 years. Application of linear regression analysis to the serum Cu levels and the intake of energy, fibre, iron and magnesium showed a statistically significant negative correlation (P < 0.05) among them in all the subjects. However, no correlation was observed when the serum Cu levels were related to the intake of zinc or vitamin C. Therefore, at the daily intake levels of these two nutrients, they do not interfere in the absorption of copper and hence do not affect the corporal status of this element in the elderly. Blood erythrocyte and haemoglobin concentrations do not show any significant correlation with the serum Cu concentrations (P > 0.05).