Association between lower hair zinc levels and neural tube defects.

Though folic acid supplementation has reduced the incidence of Neural Tube Defects (NTD), NTD still constitutes one of the important congenital malformations having wide medical, social and ethical implications. Zinc deficiency has been reported to produce NTD in animals. This study was designed to evaluate zinc status of the newborn babies with NTD and their mothers. Eighty newborn babies with NTD and their mothers served as cases. Eighty apparently normal newborn babies and their mothers served as controls. Serum and scalp hair zinc levels were analyzed by atomic absorption spectrophotometry. The mean (+/- SD) serum and hair levels in normal mothers were 74.1 +/- 4.1 micrograms/dl and 142.3 +/- 8.0 micrograms/g respectively. The mean (+/- SD) serum and hair levels of the mothers who delivered NTD babies were 75.7 +/- 5.6 micrograms/dl and 129.9 +/- 5.3 micrograms/g respectively. The mean (+/- SD) serum and hair levels in normal newborn babies were 77.8 +/- 5.3 micrograms/dl and 188.8 +/- 6.2 micrograms/g respectively. The mean (+/- SD) serum and hair levels in NTD babies were 80.1 +/- 12.9 micrograms/dl and 174.2 +/- 10.7 micrograms/g respectively. The hair zinc levels of the affected babies and their mothers were significantly lower (P < 0.001) than the controls. This study has found association between NTD and decreased hair zinc levels and large population based studies are recommended to confirm the association between zinc and NTD and to investigate whether zinc supplementation would reduce the overall incidence of NTD.