Long-term marginal zinc deprivation in rhesus monkeys. II. Effects on maternal health and fetal growth at midgestation.

Adult nonpregnant female rhesus monkeys fed purified diets containing 100 or 4 ppm zinc for 1 yr were mated then studied through midgestation. At mating, zinc-deprived (ZD) monkeys showed maternal lymphocyte response to mitogens concanavalin A (Con A) and phytohemagglutinin (PHA), serum uric acid and carbon dioxide, and WBC lower than in control (C) monkeys. There was a significant positive association between plasma zinc and PHA response. At midgestation, discriminant analysis revealed that maternal lymphocyte response to Con A, fetal abdominal circumference (by ultrasound), plasma fibrinogen, serum IgM, and amniotic fluid iron level were discriminators for diet group, all lower in ZD than in C monkeys. Maternal plasma and RBC zinc at midgestation were positively associated with fetal growth and plasma uric acid. These observations suggest that immune function (ie, mitogen response and serum immunoglobulin level) is a strong discriminator of dietary zinc deprivation in rhesus monkeys, both before and during pregnancy.