[Epidemiological characteristics of serum vitamin B(12) and folate levels in women awaiting delivery]

Objectives: To analyze the epidemiological characteristics and levels of vitamin B(12) and folate as well as their relationship in women awaiting delivery, in Shaanxi province. Methods: Data were collected from healthy pregnant women who gave birth at six top hospitals in Shaanxi, from January 2014 to December 2016. Blood samples were taken prenatally to determine the levels of vitamin B(12) and folate. Quantile regression model was used to analyze the relationship between the levels of vitamin B(12) and folates in women awaiting delivery. Results: A total of 1 277 women awaiting delivery were included in this study. Among them, the median level of serum vitamin B(12) was 164.7 pg/ml, in women at late pregnancy, with the deficiency rate as 69.6%, while the median level of serum folate was 7.6 ng/ml, with the deficiency rate as 12.1%. 58.4% of these women presented simple vitamin B(12) deficiency and 0.9% with simple folate deficiency. Women living in rural areas showed lower levels of both vitamin B(12) and folate than the women from the urban areas. Both the levels of vitamin B(12) and folate increased with age but were significantly lower in women under the age of 25. Among those with or without folate deficiency, the average difference in the levels of vitamin B(12) was 37.62 pg/ml. Quantile regression models showed that the vitamin B(12) levels in women with folate deficiency were significantly lower than those without, despite the different levels of vitamin B(12). This difference appeared increasing along with the increase of the vitamin B(12) levels. Conclusions: Our data showed that both vitamin B(12) and folate were deficient in women awaiting delivery, in Shaanxi. We suggest that vitamin B(12) should also be added into the folic acid supplementation program, together with the reinforcement on health education program to improve the awareness of nutrient supplementation in rural and young women. Hopefully, these strategies could increase the levels of both vitamin B(12) and folate, in the province.