An effect of oral vitamin B12administration on growth performance and fur quality characteristics in mink kits fed an anaemiogenic diet has earlier been found. The present data confirmed that kits fed the unsupplemented anaemiogenic diet developed anaemia with low haemoglobin, haematocrit and erythrocyte counts, microcytosis, anisocytosis, and low iron and cobalt contents in the liver. Oral vitamin B12supplementation, but not injections, partly restored iron status, documented by haemoglobin and haematocrit values not being significantly different from the control group, and increased liver cobalt content. Iron therapy alone or combined with vitamin B12resulted in normal iron status. A mechanism for the effect of vitamin B12in preventing anaemia is suggested.