Risk factors for prevalence of folic acid deficiency in Chinese lactating women in 2013

Abstract

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.