Objective: The study aimed to assess the
folic acid status of lactating women in China and to analyze factors related to
folic acid deficiency in these subjects. Methods: The data on lactating women were extracted from the Chinese National Nutrition and Health Surveillance in 2013. By a multi-stage stratified cluster random sampling method, 10 331 lactating women were selected for the study. The lactating women, 0-24 months postpartum, were from 55 sites in 30 provinces of China, excluding the Tibet Autonomous Region. A standard questionnaire was used to obtain general information and dietary intake during the previous one month period was collected using a food frequency questionnaire. A total of 20% of the total number of lactating women were randomly selected to analyze serum
folic acid. Finally, 1 894 lactating women, with questionnaire results and serum
folic acid data, were included in the study. Serum
folic acid concentrations were analyzed using an electro-chemiluminescence immunoassay method.
Folic acid deficiency was defined as a serum
folic acid level <2 ng/ml. A multiple logistic regression analysis was used to analyze the factors associated with
folic acid deficiency in these women. Results: After excluding abnormal values, 1 894 lactating women were included in the study. Based on our findings, the prevalence of
folate deficiency was 3.0% (56/1 894) in lactating women in China. The prevalence of
folic acid deficiency was 0.3% (1/388), 1.3% (7/550), 6.0% (38/639) and 3.2% (10/317) in larger, medium or small cities, general rural counties and poor rural counties, respectively. The prevalence of
folic acid deficiency was 6.3% (17/269) and 2.4% (39/1 623) for minority and Han ethnic groups, respectively, and was 6.3% (52/823) and 0.4% (4/1 071) for subjects in northern and southern areas of China, respectively. Binary unconditionally logistic regression was used to analyze the factors associated with
folic acid deficiency in the lactating women. The results showed that, compared with those living in the south and those in the Han ethnic group, those living in the north and belonging to the minority ethnic group had a greater risk of
folic acid deficiency, with (OR=3.63, 95% CI: 1.64-8.05) and (OR=5.42, 95% CI: 1.75-16.74), respectively. With each month of age during childhood, the prevalence of
folic acid deficiency decreased by 10% (OR=0.90, 95%CI: 0.85-0.96). Compared with low income subjects, those with middle incomes had OR (95%CI) of 0.25 (0.10-0.60) for
folic acid deficiency. A lesser intake of cereal was associated with a greater risk of
folic acid deficiency in lactating women (OR=3.04, 95%CI: 1.18-7.79). A lesser intake of tubers was a protective factor for
folic acid deficiency in lactating women (OR=0.29, 95% CI:0.12-0.70). Conclusion: The
folic acid status of Chinese lactating women has, in general, recently improved. However, living in northern areas, during early lactating periods, belonging to an ethnic minority, living in rural areas, having a low income, lower intake of cereal and excessive intake of tubers were risk factors for
folic acid deficiency in lactating women. In these women,
folic acid intervention should be considered a priority.