Zinc

The estimated additional zinc required for pregnancy is approximately 100 mg, equivalent to 5-7% of the mother's body zinc, part of which is obtained through more efficient intestinal zinc absorption. Approximately half of this is deposited in the fetus. The EAR for pregnant women is based on an additional requirement of 2.7mg/day during the last 10 weeks of gestation. The UL is based on evidence of impaired copper status at high intakes, as for nonpregnant women. No increment is recommended for pregnancy in the UK report, based on the assumption that needs can be met through adjustments in maternal zinc metabolism.

Zinc plays critical roles in cell division, hormone metabolism, protein and carbohydrate metabolism, and immunocompetence. Because zinc deficiency in pregnant animals causes birth defects and fetal growth retardation, there has been considerable effort to determine the effects of human zinc status on pregnancy outcome, especially in developing countries, where zinc intakes are often inadequate. In an analysis of 12 randomized, controlled intervention trials, only 2 (1 in India and 1 in the United States) found that zinc supplementation increased birth weight and reduced preterm delivery risk, whereas 6 found no effect. In the United States study, a positive effect was found in low-income, obese African American women with below average plasma zinc concentrations. Trials in Peru and Bangladesh showed no such benefits. In general, however, meeting recommended zinc intakes is more difficult but more critical for women whose diets are low in animal source foods and higher in fiber. High intakes (supplements) of iron and calcium may also impair zinc absorption and therefore increase requirements.

Food Allergies

Food Allergies

Peanuts can leave you breathless. Cat dander can lead to itchy eyes, a stuffy nose, coughing and sneezing. And most of us have suffered through those seasonal allergies with horrible pollen counts. Learn more...

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