Wasted sheep and premature infants: the role of trace metals in hematopoiesis.

Trace element deficiencies and toxicities are not commonly encountered in clinical practice, particularly in regions where there is access to adequate nutrition and occupational exposures are regulated. However, specific clinical scenarios associated with trace metal deficiency and toxicity states do exist. Often, clues to the presence of these states may lie in the development of blood count abnormalities. The consultant haematologist is frequently involved in the care of these patients, and it is with this audience that this review is intended. This review will focus on the trace metals required for normal hematopoiesis including their function, metabolism, deficiency and toxicity states, and the clinical situations underlying these. As much of the information regarding trace metal disease states has arisen from veterinary medicine and from human case reports, these will be summarized and highlighted in this review.