Serum alkaline phosphatase after treatment of zinc deficiency in humans.

The response of serum alkaline phosphatase (AP) during the first 2 weeks of zinc (Zn) replacement therapy was studied retrospectively in three Zn-deficient adults. The ratio of the maximal posttreatment to pretreatment serum AP level (AP ratio) correlated inversely with pretreatment serum Zn level. A similar linear relationship was apparent when the AP ratio was calculated from published cases of Zn deficiency of diverse etiologies. Serial determinations of serum AP and calculation of the AP ratio during a trial of Zn therapy may provide biochemical confirmation of the adequacy of Zn replacement and could potentially be useful in detection of subclinical Zn deficiency.