Iron bioavailability from fortified fluid milk and petit suisse cheese determined by the prophylactic-preventive method.

In this research, we measure the iron bioavailability of micronized ferric orthophosphate when it is used to fortify low-fat fluid milk enriched with calcium and petit suisse cheese using the prophylactic-preventive method in rats. Four groups of male weaned rats received a basal diet (control diet; 6.5 ppm Fe), a reference standard diet (SO4Fe; 18.2 ppm Fe), a basal diet using iron-fortified fluid milk as the iron source (milk diet; Fe ppm 17.9), and a basal diet using iron-fortified petit suisse cheese as the iron source (cheese diet; 18.0 ppm Fe) for 22 d. The iron bioavailability of the different sources was calculated as the ratio between the mass of iron incorporated into hemoglobin during the experiment and the total iron intake per animal. The relative biological values with regard to the reference standard (RBV%) were 61% and 69% for the milk and cheese diet, respectively. These results show that according to this method, the iron bioavailability in both fortified foods can be considered as medium bioavailability rates.

Nicotine exposure among nondependent smokers.

Most theories of dependence imply that repeated exposure to an addictive drug leads inexorably to dependence. We examined nicotine exposure in "tobacco chippers," who smoke regularly without developing dependence. Blood samples were obtained before and after 10 chippers (smoking up to 5 cigarettes per day) and 12 dependent smokers (20 to 40 cigarettes per day) smoked a cigarette. Chippers' blood nicotine levels increased significantly, in amounts equaling those of dependent smokers. Assays of cotinine (a long-lasting nicotine metabolite) also suggested that chippers' per-cigarette nicotine absorption equaled that of dependent smokers. Chippers' cotinine levels were also compared with those of heavy smokers (38 cigarettes per day) whose consumption was reduced to 5 cigarettes per day in a previously published study. The heavy smokers compensated by tripling their per-cigarette nicotine intake. Chippers did not seem to be compensating; their cotinine values equaled those expected when regular smokers were not compensating for reduced cigarette availability.