Relationships of maternal zinc intake from animal foods with fetal growth

Zn is an essential element for human growth. The nutritional adequacy of dietary Zn depends not only on the total Zn intake, but also on the type of food source (i.e. of plant or animal origin). We investigated the association between maternal dietary Zn intake from animal and plant food sources and fetal growth. A total of 918 pregnant women at 12-28 weeks of gestation were selected from the Mothers and Children's Environmental Health study in Korea. Dietary intakes in mid-pregnancy were estimated by a 24 h recall method, and subsequent birth weight and height were obtained from medical records. Multiple regression analysis showed that maternal Zn intake from animal food sources and their proportions relative to total Zn intake were positively associated with birth weight (P=0.034 and 0.045, respectively) and height (P=0.020 and 0.032, respectively). Conversely, the percentage of Zn intake from plant food sources relative to total Zn intake was negatively associated with birth height (P=0.026) after adjustment for covariates that may affect fetal growth. The molar ratio of phytate: Zn was negatively associated with birth weight (P=0.037). In conclusion, we found that the absolute amounts of Zn from different food sources (e.g. animal or plant) and their proportions relative to total Zn intake were significantly associated with birth weight and height. A sufficient amount of Zn intake from animal food sources of a relatively higher Zn bioavailability is thus encouraged for women during pregnancy.