Supplemental zinc lowers miscarriage risk in cows

The risk of miscarriage increased when both serum zinc decreased and copper concentrations increased. Methionine-supplemented cows had a higher risk of fetal loss compared with zinc-methionine-supplemented cows (odds ratio = 2.98). Cows which received no supplements had a higher risk for miscarriage than did zinc-methionine-supplemented cows. Our results suggest that inflammation and zinc nutriture may play an important role in miscarriage in dairy cows.

Low calcium, iron, zinc and magnesium associated with higher rate of miscarriage

Female rats received a control or a 50% mineral-restricted diet for 12 weeks, by which time  mineral-restricted rats had lower plasma iron, zinc, magnesium and calcium concentrations. Following mating with control males, a third of the mineral-restricted dams were shifted to the control diet from parturition. RESULTS: Pregnant mineral-restricted dams had a higher miscarriage rate, and body weights of their pups at birth and weaning were lower.

Bunnies with low fertility found deficient in zinc and phosphate; supplementation restores fertility

A number of does was classified according to their initial litter size to high (> 6 bunnies, group 1) and low (< 5 bunnies, group 2) in New Zealand White rabbits. The number of matings/conception, total mortality, corpora lutea/fetus, number and percentage of resorbed foeti were markedly higher in group 2 than in group 1. The litter weight, number of fetuses, implantation sites, and corpora lutea in group 2 showed a marked decrease over group 1. Serum and urine progesterone levels in pregnant rabbits of group 2 were significantly lower than in group 1. The zinc content in serum, fetal dry weight and uterine horn dry weight, and serum inorganic phosphate in group 2 were significantly lower than in group 1. The litter size was significantly correlated with zinc and inorganic phosphate in group 2, while it was correlated with serum and urine progesterone in the two groups. The treatment of group 2 does with calcium carbonate, sodium phosphate dibasic, and zinc acetate in drinking water improved the serum progesterone, urine progesterone, and non-efficacious progesterone in addition to serum zinc and inorganic phosphate, which led to improvement of the number of matings/conception, litter size and litter weight, and lowered total mortality.

Zinc deficiency restricts fetal growth and causes birth defects

Zinc deficiency in pregnant experimental animals limits fetal growth and, if severe, causes teratogenic anomalies. Although the data from human studies are not consistent, similar outcomes have been observed and were associated with poor maternal zinc status.

Tremendous amount of zinc needed for eggs to reach full maturity

New research reveals healthy eggs need a tremendous amount of zinc to reach maturity and be ready for fertilization. Northwestern scientists, working with mice, discovered the egg becomes ravenous for zinc and acquires a 50 percent increase in the metal in order to reach full maturity before becoming fertilized. The flood of zinc appears to flip a switch so the egg can progress through the final stages of meiosis. Zinc levels were significantly higher in eggs than other important metals such as iron and copper. Zinc was the only metal to change significantly in concentration during the maturation process. There's no link yet to zinc content in the egg and the nutritional status of women, but Kim plans to research that area.

25 mg zinc led to higher birth weights and head circumference

Women who were taking a non-zinc-containing prenatal multivitamin/mineral tablet were randomized to receive either a daily dose of 25 mg of zinc or a placebo until delivery. RESULTS:  In all women, infants in the zinc supplement group had a significantly greater birth weight (126 g) and head circumference (0.4 cm) than infants in the placebo group. In women with a body mass index less than 26 kg/m2, zinc supplementation was associated with a 248-g higher infant birth weight and a 0.7-cm larger infant head circumference. Plasma zinc concentrations were significantly higher in the zinc supplement group. CONCLUSIONS: Daily zinc supplementation in women with relatively low plasma zinc concentrations in early pregnancy is associated with greater infant birth weights and head circumferences, with the effect occurring predominantly in women with a body mass index less than 26 kg/m2.

Zinc prevents infection-related birth defects in mice

Maternal infection during the first trimester of pregnancy has been associated with preterm birth, miscarriage, growth retardation, and birth defects. Previously, our group has shown that subcutaneous injection of zinc prevents endotoxin [lipopolysaccharide (LPS)]-induced birth defects. The purpose of this study was to investigate whether increasing or decreasing dietary zinc alters the teratogenic effects of LPS. Female mice were mated and fed diets containing 5, 35, or 100 mg/kg zinc. LPS-treated fetuses from dams fed 5 and 35 mg/kg zinc diet had a significantly higher number of abnormalities per litter (2- and 1- fold saline controls, respectively) compared with those from LPS + zinc supplemented dams, which were not significantly different from the saline control groups. The beneficial effect and importance of zinc was also reflected in the larger size of fetuses (weight and crown-rump length) from the LPS + zinc-supplemented treatment group. We have demonstrated that low dietary zinc during exposure to infection (i.e. LPS) in pregnancy augments the negative impact of LPS alone, and that dietary zinc supplementation throughout pregnancy ameliorates LPS-induced birth defects.

Low zinc in PCOS

Animals with endometritis, vaginal adhesions, and ovarian cysts revealed lower serum zinc concentration than that of control group.

PCOS and Miscarriage

Low zinc/copper ratio and magnesium in PMS sufferers

The mean magnesium level and the zinc/copper ratio were significantly lower in premenstrual tension syndrome patients than in the control group.

Magnesium and Miscarriage

Zinc lowers copper levels, raises insulin and insulin resistance

Compared to baseline, plasma zinc and zinc:copper plasma ratio increased, but plasma copper decreased after zinc supplementation (day 30) and discontinuation (day 60). Zinc supplementation and discontinuation had no effect on TSH, T3, and T4. Fasting serum insulin and insulin resistance increased (27% and 47%, respectively) on day 60 compared to baseline, suggesting a delayed effect of zinc supplementation. Moreover, plasma zinc was positively associated with serum insulin and insulin resistance after zinc supplementation (day 30), indicating that supplemental zinc may impair glucose utilization.

No negative effects on pregnancy with zinc lower than 75 mg/day

In these studies, more than 2500 pregnant women were given zinc at different doses. None of these studies described any abnormalities, congenital malformation, harmful effects or risk for the fetus associated with the use of zinc during pregnancy at doses below 75 mg/day. This literature review shows that use of zinc salts in pregnant women is beneficial in those with zinc deficiency but that it has no harmful effects in those without zinc deficiency.

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