Physiological variations of serum levels of copper, zinc, iron and manganese.

The effect of adult age, sex, diurnal rhythm and pregnancy on the serum level of copper, zinc, iron and manganese determined by flameless atomic absorption is described. There was no diurnal variation for serum copper but a significant decrease for the other three metals. Copper concentration is lower in males and iron lower in females. Zinc and manganese are identical for both sexes and there is no age dependent change in adults. During pregnancy, zinc and iron decrease and copper and manganese increase.