Effect of inositol hexaphosphate on retention of zinc and calcium from the human colon

Colonic retention of zinc and calcium was studied after installation during colonoscopy in 11 patients of a solution of 30 mumol zinc, 6.4 mmol calcium and 500 mumol inositol hexaphosphate (phytic acid) labelled with 65Zn and 47Ca. Whole-body retention of the radionuclide at day 13 was 1.0 +/- 1.0 per cent (mean +/- s.d.) for zinc and 4.0 +/- 2.9 per cent for calcium. The retention of zinc but not of calcium was lower than observed earlier under similar conditions from a solution not containing phytic acid and indicates formation of an indigestible complex between phytic acid and zinc. Addition of amino acids to the solution in 3 subjects did not seem to affect the retention of zinc and calcium.