Pregnancy support- Vitamin Deficiencies

Zinc - updated: 03 November 2008

Zinc and pregnancy

Gynecol Obstet Fertil. 2005 Apr;33(4):253-8. Epub 2005 Apr 7

Favier M, Hininger-Favier I.

Zinc, an essential trace element, plays a critical role in normal growth and development, cellular integrity and many biological functions, including protein synthesis and nucleic acid metabolism. Since all these are involved in cell division and growth, zinc is believed to be important for foetal growth and development. Zinc requirement is increased during pregnancy but the lack of a valid indicator precludes a true estimate of zinc deficiency in pregnancy even in developed countries. This review examines the possibility that a gestational deficiency of zinc can adversely affect the pregnancy outcome. Preliminary human data suggest a beneficial effect of prenatal zinc supplementation trials in particular on infant's neurobehavioral development. In the light of the currently available information, zinc supplementation at therapeutic load (30 mg/day) as it is proposed for the treatment of hormonal skin disorders to adolescents, cannot be toxic.

Publication Types:

• Review

Zinc supplementation for improving pregnancy and infant outcome

Cochrane Database Syst Rev. 2007 Apr 18;(2):CD000230

Mahomed K, Bhutta Z, Middleton P.

BACKGROUND: It has been suggested that low serum zinc levels may be associated with suboptimal outcomes of pregnancy such as prolonged labour, atonic postpartum haemorrhage, pregnancy-induced hypertension, preterm labour and post-term pregnancies, although many of these associations have not yet been established. OBJECTIVES: To assess the effects of zinc supplementation in pregnancy on maternal, fetal, neonatal and infant outcomes. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (February 2007). SELECTION CRITERIA: Randomised or quasi-randomised trials of zinc supplementation in pregnancy. DATA COLLECTION AND ANALYSIS: Two review authors applied the study selection criteria, assessed trial quality and extracted data. When necessary, study authors were contacted for additional information. MAIN RESULTS: We included 17 randomised controlled trials (RCTs) involving over 9000 women and their babies. Zinc supplementation resulted in a small but significant reduction in preterm birth (relative risk (RR) 0.86, 95% confidence interval (CI) 0.76 to 0.98 in 13 RCTs; 6854 women). This was not accompanied by a similar reduction in numbers of babies with low birthweight (RR 1.05 95% CI 0.94 to 1.17; 11 studies of 4941 women). No significant differences were seen between the zinc and no zinc groups for any of the other primary maternal or neonatal outcomes, except for a small effect favouring zinc for caesarean section (four trials with high heterogeneity) and for induction of labour in a single trial. No differing patterns were evident in the subgroups of women with low versus normal zinc and nutrition levels or in women who complied with their treatment versus those who did not. AUTHORS' CONCLUSIONS: The 14% relative reduction in preterm birth for zinc compared with placebo was primarily in the group of studies involving women of low income and this has some relevance in areas of high perinatal mortality. There was no convincing evidence that zinc supplementation during pregnancy results in other useful and important benefits. Since the preterm association could well reflect poor nutrition, studies to address ways of improving the overall nutritional status of populations in impoverished areas, rather than focusing on micronutrient and or zinc supplementation in isolation, should be an urgent priority.

Publication Types:

• Review

Zinc status in pregnancy: the effect of zinc therapy on perinatal mortality, prematurity, and placental ablation

Ann N Y Acad Sci. 1993 Mar 15;678:178-92

Jameson S.

Zinc is present in and indispensable to all forms of life. Zinc is essential for the normal growth of human beings, and zinc proteins have been shown to be involved in the transcription and translation of the genetic material. Zinc deficiency has been incriminated in infertility, abortions, malformations, fetal intrauterine growth retardation, premature and postmature births, perinatal death, and abnormal deliveries with dystocia and placental ablation. Risk groups for developing zinc deficiency, which in turn might modify the expression of the underlying disease, are found among those with insufficient food intake, especially in protein malnutrition; abnormal mucosal uptake, as in celiac disease; abnormal intestinal losses, as in steatorrhea and inflammatory bowel disease; abnormal renal excretion, as in diabetes with insufficient metabolic control; alcoholism; and treatment with diuretic drugs. Zinc deficiency could be identified by means of fasting serum or plasma samples or the more laborious estimation of zinc in leucocytes or monocytes if sampling and handling is carefully performed and if stressful situations and acute-phase reactions as fever, delivery, or abortion are avoided. Zinc therapy in identified low-zinc groups has given favorable results and has reduced the frequencies of premature birth, placental ablation, perinatal death, and postmaturity. It is suggested, as we did in 1980, that these data are compatible with the presence of a zinc-deficiency syndrome in pregnancy, which includes increased maternal morbidity, abnormal taste sensations, abnormally short or prolonged gestations, inefficient labor, atonic bleeding, and increased risks to the fetus such as malformations, growth retardation, prematurity, postmaturity, and perinatal death.

Publication Types:

• Review

Zinc deficiency in women, infants and children

J Am Coll Nutr. 1996 Apr;15(2):113-20

Prasad AS.

Zinc deficiency in humans is widespread and is more prevalent in areas where the population subsists on cereal proteins. Conditioned deficiency of zinc is seen in many diseased states. A mild deficiency of zinc in pregnancy is associated with increased maternal morbidity, abnormal taste sensation, prolonged gestation, inefficient labor, atonic bleeding, and increased risks to the fetus. Among the urban poor in the US, a marginal zinc intake during pregnancy was associated with increased risk of preterm and very preterm delivery. Factors responsible for zinc deficiency in premature infants include high fecal losses of zinc, low body stores of zinc at birth, and increased zinc requirement during rapid growth. Zinc supplemented infants demonstrated improved linear growth velocity and maximum motor development scores. Marginal and moderate growth impairment in children as a consequence of inadequate zinc intake has been reported from many developed and developing countries. In one study from Japan, 21 prepubertal children were diagnosed to have zinc deficiency. The caloric intake, growth velocity, serum zinc, and plasma insulin-like growth factor-1 increased significantly in the zinc supplemented group. The clinical manifestations of zinc deficiency include growth retardation, hypogonadism in males, neurosensory disorders, cell-mediated immunological dysfunctions, and skin changes. Approximately 300 enzymes are known to require zinc for their activities. Zinc is required for DNA synthesis, cell division and protein synthesis. Several hundreds of zinc containing nucleoproteins are probably involved in gene expression of various proteins. A deficiency of zinc also affects proliferation and maturity of lymphocytes adversely.

Publication Types:

• Review

Use of national food balance data to estimate the adequacy of zinc in national food supplies: methodology and regional estimates

Public Health Nutr. 2005 Oct;8(7):812-9

Wuehler SE, Peerson JM, Brown KH.

OBJECTIVES: Adequate zinc nutriture is critically important for human health, but the development of programmes to control zinc deficiency is limited by the lack of reliable information on population zinc status. The present analyses were conducted to: (1) estimate the absorbable zinc content of national food supplies; (2) compare this information with theoretical population requirements for zinc; and (3) use these results to predict national risks of inadequate zinc intake. SETTING AND DESIGN: National food balance data were obtained for 176 countries from the Food and Agriculture Organization of the United Nations. The amount of absorbable zinc in these foods was estimated from food composition data, and zinc absorption was predicted using a model developed by the International Zinc Nutrition Consultative Group (IZiNCG). Demographic data were obtained from United Nations estimates, and age- and sex-specific physiological requirements for absorbable zinc were estimated using IZiNCG recommendations. RESULTS AND CONCLUSIONS: The mean per capita absorbable zinc content of national food supplies ranged from 2.98-3.01 mg day(-1) in Western Europe and USA & Canada to 2.09 mg day(-1) in Southeast Asia. The estimated percentage of individuals at risk of inadequate zinc intake ranged from 9.3-9.5% in the regions of North Africa & Eastern Mediterranean and USA & Canada to 33.1% in Southeast Asia. Overall, approximately 20.5% of the world's population is estimated to be at risk of inadequate zinc intake. Data on the absorbable zinc content of national food supplies can be used to determine whether further assessments of population zinc status and development of intervention programmes are warranted.

Publication Types:

• Review

Publication Types:

• Review

Publication Types:

• Review

Publication Types:

• Review

Publication Types:

• Review