Implications of zinc on fetal neural tube defects

Zinc is essential for normal growth and differentiation in all mammalian species and it is reported that folic acid supplementation has reduced the incidence of neural tube defects (NTD). It is still considered one of the important congenital malformations having wide implications. Zinc deficiency has been reported to produce NTD in animals. The present study was undertaken to evaluate zinc status of newborn babies with NTD and their mothers. Blood samples were taken from 287 mothers and their babies having NTD and from 110 controls visiting hospitals and health clinics. Zinc level as μg/ml for blood and serum and μg/g for cell mass were determined on GBC 932 atomic absorption spectrophotometer (Australia) by fluorometery. The mean maternal blood, serum and cell mass concentration in NTD group (14.56 ± 1.34 μg/ml, 0.6 ± 0.01 μg/ml, 5.64 ± 0.35 μg/gm respectively) were significantly lower than those of the control mothers (24.15 ± 2.95 μg/ml, 0.72 ± 0.03 μg/ml, 7.37 ± 0.44 μg/gm respectively). There is a significant decrease in the concentration of Zinc in newborns having NTD (15.65 ± 3.18 μg/ml, 0.56 ± 0.08 μg/ml, 5.11 ± 0.18 μg/gm respectively) as compared with normal newborns (28.04 ± 1.1 μg/ml, 0.59 ± 0.08 μg/ml and 6.08 ± 0.29 μg/gm respectively). Maternal nutritional zinc deficiency in newborns and their mothers is thought to be one of the factors responsible for NTD. However, the lowered zinc concentration may be influencing the causation of NTD. More investigations on zinc status in mothers during antenatal period, especially in the prenatal development and antenatal zinc status including normal babies and NTD babies are required at population level.