Kristensen Mette Bach, Hels Ole, Morberg Catrine M, Marving Jens, Bügel Susanne, Tetens Inge
Department of Human Nutrition, Center for Advanced Food Studies (LMC), The Royal Veterinary and Agricultural University, Rolighedsvej 30, DK-1958 Frederiksberg C, Denmark.
Br J Nutr. 2006 May;95(5):963-7. doi: 10.1079/bjn20051486.
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.
素食饮食中锌的生物利用率通常较低，主要原因是锌含量低且植酸含量高。本研究的目的是确定与植酸浓度相同的肉类饮食相比，素食饮食中锌的分数吸收和总吸收情况。采用随机交叉设计，包括三个为期5天的全天饮食阶段，分别为素食饮食或含有波兰产肉类或丹麦产肉类的饮食。12名健康女性受试者完成了该研究。所有饮食的植酸含量都很高（1250微摩尔/天），在肉类饮食中，主餐含有60克猪肉。所有主餐都用放射性同位素65Zn进行了外源性标记，并在全身计数器中测量锌的吸收情况。全天饮食的平均锌含量为：波兰肉类饮食9.9（标准误0.14）毫克，丹麦肉类饮食9.4（标准误0.19）毫克，素食饮食7.5（标准误0.18）毫克。锌的分数吸收没有差异（波兰肉类饮食：27（标准误1.2）%，丹麦肉类饮食：27（标准误1.9）%，素食饮食：23（标准误2.6）%）。素食饮食中吸收的总锌量显著较低（波兰肉类饮食的平均锌吸收量：2.7（标准误0.12）毫克/天（P<0.001），丹麦肉类饮食：2.6（标准误0.17）毫克/天（P=0.006），素食饮食：1.8（标准误0.20）毫克/天）。总之，与肉类饮食相比，素食饮食导致吸收的锌量较低，原因是肉类饮食中的锌含量较高，但锌的分数吸收没有差异。
