Serum, Leucocyte, Sweat and Hair Zinc Levels—a Correlational Study

Abstract

Zinc status is difficult to assess, and much emphasis has been placed on serum zinc levels. However, the distribution of zinc in the human body suggests that serum zinc will not be a good indicator of zinc status. The use of zinc measurements in red cells, leucocytes, hair, urine and sweat samples is discussed. Measurements of sweat zinc concentration were performed on two adult control groups (n=30 and n=53) and on 145 children aged from 2 to 15 years. The reference ranges for sweat zinc were established. A comparison is made of hair, leucocyte, serum and sweat zinc levels in 10 people with normal hair zinc, 10 with low hair zinc, 4 with high hair zinc and 16 with clinical signs of zinc deficiency. The results demonstrate that sweat zinc is the sample of choice for the assessment of zinc status and that leucocyte zinc is almost as useful. Serum zinc is unreliable except in severe deficiencies and the danger of relying on serum zinc to exclude a diagnosis of deficiency is emphasized.