MEASUREMENT OF ZINC BIOAVAILABILITY FROM BEEF AND A READY-TO-EAT HIGH-FIBER BREAKFAST CEREAL IN HUMANS - APPLICATION OF A WHOLE-GUT LAVAGE TECHNIQUE

We measured zinc absorption in humans from two different foods, using a whole-gut lavage technique. Healthy adults (n = 8) were given test f oods containing approximately 4 mg (61.2 mumol) Zn as either beef or a high-fiber, ready-to-eat breakfast cereal. Basal zinc loss in the gut was measured after giving only 200 mL water alone after an overnight fast. Mean polyethylene glycol (PEG) recovery, a nonabsorbable fecal m arker, was 95 +/- 2% (xBAR +/- SE). There was no significant differenc e of PEG recoveries with the various treatments. True absorption of zi nc was 11.0 +/- 5.4 mumol (716.3 +/- 355.9 mug) for breakfast cereal a nd 34.8 +/- 3.5 mumol (2274.1 +/- 230.2 mug) for beef. Fractional zinc absorption was significantly lower for breakfast cereal compared with beef, 14.7 +/- 6.7% vs 55.1 +/- 4.6%, respectively. Our findings demo nstrate that zinc absorption can be measured in humans from single foo ds containing a physiological dose of zinc by using the whole-gut lava ge absorption technique and that zinc bioavailability from beef is abo ut fourfold greater than from a high-fiber breakfast cereal.