Table 2.
The role of zinc in embryogenesis. Evidence from animal and human studies.
| A. Evidence from Experimental Animal Model. | |||||
|---|---|---|---|---|---|
| Study | Model | Study Design | Main Results | ||
| Hurley et al., 1969 [25] | Pregnant rats | Severe zinc deficiency induced by the use of a diet containing isolated soybean protein (treated with a chelating agent). Controls fed with zinc-supplemented diet | 98% of full-term fetuses with congenital malformations of the tail (72%), finger (64%), lungs (54%), palate (42%), brain (47%), eye (42%), feet (38%), urogenital tract (21%) | ||
| Hicory et al., 1979 [26] | Pregnant rats | Eighteen rats fed with zinc deficient diet and 18 fed with zinc supplemented diet during pregnancy | Malformations of the trunk and limbs in fetuses of zinc deficient mothers | ||
| Rogers et al., 1985 [27] | Long-Evans hooded pregnant rats and fetuses | Determination of teratogenicity of maternal Zn deficiency in the Long-Evans hooded rat, examining the effects of Zn deficiency on Zn, Fe, and Cu concentrations in maternal and fetal tissues. Evaluation of the effects of Zn deficiency on the risk of abdominal and skeletal malformations | All fetuses presented malformations when zinc was supplemented at low doses | ||
| Falchuk et al., 2001 [28] | Frog embryos | Deprivation of zinc in embryos to evaluate the effects on metallo-proteins activity and on organ formation and development | Agenesis of dorsal organs (including brain, eyes and spinal cord) in embryos developed in the absence of zinc. | ||
| B. Evidence from Clinical Studies in Human. | |||||
| Study | Population | Study Design | Results | ||
| Velie et al., 1999 [29] | Mothers of infants with neural tube defect (NTD) compared with mothers of healthy neonates (controls) | Retrospective study on pre-conceptional use of vitamin, mineral, and food supplements, by filling a specific questionnaire | Risk of NTDs decreased with the increase in maternal pre-conceptional zinc intake | ||
| Cengiz et al., 2004 [30] | Mothers of infants with neural tube defect diagnosed in the second trimester of gestation compared with mothers of healthy neonates (controls) | Case-control study to investigate the relationship between maternal micronutrient serum level (including zinc) and NTD occurrence in neonates | No strict correlation between zinc concentrations and NTD | ||
| Zeyreks et al., 2009 [31] | Mothers of infants with neural tube defect (NTD) compared with mothers of healthy neonates (controls) | Case-control study to investigate the relation between cord blood and maternal micronutrient serum levels of (including zinc) and NTD occurrence in neonates | The mean maternal serum zinc level in mothers of neonates with NTD was significantly lower than those of controls | ||
| Dey et al., 2010 [32] | Mothers of infants with neural tube defects (NTD) compared with mothers of healthy neonates (controls). | Hospital-based case-control study conducted with the objective of finding the relationship between serum zinc levels in newborns and their mothers and NTDs in a Bangladeshi population | NTD were more likely in subjects born from mothers with lower serum zinc level | ||