Comparison of Vitamin D Levels and Related Factors in Pregnant Women and Neonates Exposed to Second-Hand Smoke.

Introduction: Exposure to second-hand smoke, a significant public health issue today, may lead to various health problems, especially in pregnant women and their infants. Low vitamin D levels during pregnancy may lead to preeclampsia and gestational diabetes in the mother, while it may cause low birth weight and respiratory problems in the infant.

Method: The study group consisted of 42 mothers, who smoked regularly, and their infants and 45 mothers (passive smokers), who were regularly exposed to second-hand smoke in their home environment, although they did not smoke, and their infants. Meanwhile, the control group consisted of 46 healthy mothers, who did not smoke and were not exposed to second-hand smoke at home, and their infants with similar gestational age and birth weight. Blood samples were taken as two different samples, from the mother and the baby, and 25-hydroxyvitamin D (25(OH)D) and related blood parameters were studied and compared statistically.

Results: 25(OH)D, calcium, and magnesium levels of mothers who smoked were significantly lower than those who were exposed to second-hand smoke and those who did not. Moreover, the vitamin D levels of mothers and babies exposed to second-hand smoke in the non-smoker group were significantly lower than mothers and babies who were not exposed to second-hand smoke. In the babies of these three groups, a significant decrease was observed only in vitamin D levels.

Conclusion:  The present study shows that pregnant women and their infants exposed to second-hand smoke have lower vitamin D levels. Hence, more emphasis should be put on vitamin D monitoring and supplementation to prevent severe health problems in pregnant women and their infants exposed to tobacco smoke. Further studies are needed to assess the associated risks for maternal and fetal health as well as possible long-term implications for the infant.