title: Total zinc absorption in young women, but not fractional zinc absorption, differs between vegetarian and meat-based diets with equal phytic acid content.
abstract: Zn bioavailability is often lower in vegetarian diets mainly due to low Zn and high phytic acid contents. The objective of the present study was to determine the fractional and total absorption of Zn from a vegetarian diet in comparison with meat diets with equal concentrations of phytic acid. A randomized cross-over design, comprising three whole-day diet periods of 5 d each, with a vegetarian diet or diets containing Polish-produced meat or Danish-produced meat, was conducted. Twelve healthy female subjects completed the study. All diets had a high content of phytic acid (1250 micromol/d) and in the meat diets the main meals contained 60 g pork meat. All main meals were extrinsically labelled with the radioactive isotope 65Zn and absorption of Zn was measured in a whole-body counter. The mean Zn content of the whole-day diet was: Polish meat diet 9.9 (SE 0.14) mg, Danish meat diet 9.4 (SE 0.19) mg and vegetarian diet 7.5 (SE 0.18) mg. No difference was observed in the fractional absorption of Zn (Polish meat diet: 27 (SE 1.2) %, Danish meat diet: 27 (SE 1.9) % and vegetarian diet: 23 (SE 2.6) %). A significantly lower amount of total Zn was absorbed from the vegetarian diet (mean Zn absorption of Polish meat diet: 2.7 (SE 0.12) mg/d (P<0.001), Danish meat diet: 2.6 (SE 0.17) mg/d (P=0.006) and vegetarian diet: 1.8 (SE 0.20) mg/d). In conclusion, the vegetarian diet compared with the meat-based diets resulted in lower amounts of absorbed Zn due to a higher content of Zn in the meat diets, but no difference was observed in the fractional absorption of Zn.
authors.affiliation: Department of Human Nutrition, Center for Advanced Food Studies (LMC), The Royal Veterinary and Agricultural University, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
authors.forename: Mette Bach
authors.initials: MB
authors.lastname: Kristensen
authors.forename: Ole
authors.initials: O
authors.lastname: Hels
authors.forename: Catrine M
authors.initials: CM
authors.lastname: Morberg
authors.forename: Jens
authors.initials: J
authors.lastname: Marving
authors.forename: Susanne
authors.initials: S
authors.lastname: Bügel
authors.forename: Inge
authors.initials: I
authors.lastname: Tetens
mesh_terms: D000328:Adult; D001682:Biological Availability; D018592:Cross-Over Studies; D004032:Diet; D014676:Diet, Vegetarian; D002149:Energy Intake / Q000502:physiology; D005260:Female; D005504:Food Analysis / Q000379:methods; D006801:Humans; D007408:Intestinal Absorption / Q000502:physiology; D008460:Meat; D009747:Nutritional Physiological Phenomena / Q000502:physiology; D010833:Phytic Acid / Q000008:administration & dosage*; D015032:Zinc / Q000008:administration & dosage / Q000493:pharmacokinetics*
chemical_list: D010833:Phytic Acid; D015032:Zinc