Nutritional status of vitamin B_(12) and its influence factors in Chinese lactating women in 2013

Objective To examine the vitamin B_(12) status of lactating women in China and to analyze the factors affecting the level of serum vitamin B_(12) in these subjects. Methods Participants were from the Chinese National Nutrition and Health Surveillance in 2013. By multi-stage stratified cluster randomly sampling method, 10 331 lactating women were selected from 55 counties of 30 provinces in China. Questionnaire was conducted to collect the basic information of lactating women and the dietary intake of them in the past one month was collected by food frequency questionnaire. A total of 20% of the total number of lactating women(a total of 1976) were randomly selected to analyze serum vitamin B_(12) by electro-chemiluminescence immunoassay method. Serum vitamin B_(12) deficiency was defined as a serum vitamin B_(12) levell200 pg/mL. The distribution of serum vitamin B_(12 )was lognormal, a generalized linear model was used to analyze the factors affecting the serum vitamin B_(12) level after logarithm transformation of it. Results The median of serum vitamin B_(12)(P25, P75) in lactating women was 469. 0(349. 0, 633. 5)pg/mL, the prevalence of vitaminB_(12) deficiency was 2. 7%(53/1976)and marginal deficiency rate was 12. 8%. With the increase of the education level of the lactating women the rate of vitamin B_(12) deficiency decreased gradually. The rate of vitamin B_(12 )deficiency of the lactating women presented regional differences and varied significantly among different regionals, education levels and the mothers who were breastfeeding or not. The value of serum vitamin B_(12 )was analyzed by generalized linear regression model showed that the levels of serum vitamin B_(12) in general rural counties and medium-sized or small cities were 1. 07 and 1. 13 times higher than those in poor rural areas, respectively. The serum vitamin B_(12) level of non-lactating women was 1. 08 times higher than that of lactating women. The serum vitamin B_(12 )level of the lactating women with junior high school level or below was significantly lower than that of the lactating women with college education and university education level, 88. 3% and 85. 0% of the lactating women with college education and university education, respectively. Serum vitamin B_(12) levels were positively correlated with intake of livestock meat, fish and seafood. Conclusion The status of vitamin B_(12) in lactating women in China is good. Our findings suggest that some regionals, education levels, breastfeeding or not and livestock meat, fish meat and seafood supplement may be associated with serum vitamin B_(12 )in lactating women.