Stunting remains a major public health issue for pre-school children globally. Dairy product consumption is suboptimal in China. The aim of this study was to investigate the relationship between dairy intake and linear growth in Chinese pre-school children. A national representative survey (Chinese Nutrition and Health Surveillance) of children aged under 6 years was done in 2013. Stratified multistage cluster sampling was used to select study participants. A food frequency questionnaire was used to collect dietary information. We calculated height-for-age Z-scores (HAZs) and estimated stunting using the 2006 WHO growth standard. In total, 12,153 children aged two to four years old (24 to <60 months) were studied from 55 counties in 30 provinces in China. Approximately 39.2% (4759/12,153) of those children consumed dairy at least once per day, 11.9% (1450/12,153) consumed dairy at least once in the last week, and nearly half (48.9%, 5944/12,153) did not have any dairy in the last week. The HAZ was −0.15 ± 1.22 and the prevalence of stunting was 6.5% (785/12,153). The HAZ for children who consumed dairy at least once per day or per week was 0.11 points or 0.13 points higher than the children without dairy intake. The risk of stunting for children who consumed dairy at least once per day was 28% lower than the children without dairy intake in the last week, and the risk was similar between weekly dairy consumption and no dairy consumption (AOR: 1.03, 95% CI: 0.74–1.42) after adjusting for potential confounders, including socioeconomic characteristics, lifestyle, health status, and the intake frequency of other foods. Dairy intake was significantly associated with a higher HAZ and a lower risk of stunting for children aged 2–4 years old in China. The proportion of dairy intake was still low in Chinese pre-school children. The promotion of dairy consumption might be an effective and feasible measurement for improving linear growth in Chinese pre-school children.

Background: To investigate relationships between five single nucleotide polymorphisms (SNP) in four maternal genes involved in one carbon metabolism and adverse pregnancy outcomes, including preterm birth (PTB), low birth weight (LBW), and small-for-gestational-age (SGA). Methods: This was a prospective mother and child cohort study in Wuqiang, China. Pregnant women (n = 939) were recruited from Jun 2016 to Oct 2018. Pregnancy outcomes (PTB, LBW, and SGA) were extracted from medical records and other information including age at childbearing, maternal education level, gravidity, parity, pre-pregnancy weight and height was collected by using a structured questionnaire. The maternal serum folate concentration was measured by using Abbott Architect i2000SR chemiluminescence analyzer in the first prenatal care visit. DNA genotyping of methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C, methionine synthase reductase (MTRR) A66G, methionine synthase (MTR) A2756G, and thymidylate synthetase (TYMS) rs3819102 was processed by Sequenom MassARRAY iPLEX Platform. Univariate and multivariate logistics regression analysis were used to test the relationships between 5 SNPs and PTB, LBW, SGA. Results: Totally, 849 dyads of women and infants were included in the analysis. The prevalence of PTD, LBW, and SGA were 3.76%, 1.58%, and 5.31% respectively. The homozygote frequencies of MTHFR C677T, MTHFR A1298C, MTRR A66G, MTR A2756G, and TYMS rs3819102 were 44.2%, 1.4%, 6.7%, 1.3%, and 3.2%, and the alt allele frequencies were 66.1%, 10.8%, 24.9%, 10.5%, and 20.5% respectively. The average serum folate concentration was 11.95 ng/mL and the folate deficiency rate was 0.47%. There were no significant associations between MTHFR C677T, MTHFR A1298C, MTRR A66G, MTR A2756G, TYMS rs3819102 alleles and PTD, LBW, SGA (p > 0.05). Conclusions: In the population with adequate folate status and low prevalence of adverse pregnancy outcomes, MTHFR C677T, MTHFR A1298C, MTRR A66G, MTR A2756G, TYMS rs3819102 alleles may not be related to PTD, LBW, and SGA.

Objectives: This study sought to understand the levels of vitamin K in the mature milk of Chinese lactating mothers, thereby providing a foundation for the development of appropriate intake (AI) of vitamin K for infants aged 0–5 months. Methods: Five hundred healthy lactating mothers were selected from the mature milk bank established by the Chinese Maternal and Infant Nutrition and Health Cohort by using a simple random sample procedure. Relevant information about lactating mothers and their infants was obtained by a questionnaire survey. Vitamin K1 and vitamin K2 (MK-4 and MK-7) in mature milk were determined by liquid chromatography–tandem mass spectrometry. Results: The total concentration of vitamin K in mature milk was 4.50 (2.85–6.33) ng/mL. The concentrations of vitamin K1, vitamin K2, MK-4, and MK-7 were 2.81 (1.66–4.39) ng/mL, 1.37 (0.75–2.11) ng/mL, 1.20 (0.58–1.97) ng/mL, and 0.13 (0.08–0.19) ng/mL, respectively. The concentration of vitamin K1 was highest and the concentration of MK-7 was lowest. The concentrations of vitamin K2 and MK-4 in mature milk from the south were significantly higher than those in mature milk from the north. The total vitamin K, vitamin K2, and MK-4 concentrations in mature milk of lactating mothers residing in urban areas were higher than those in rural areas. There was a tendency for the concentration of total vitamin K and vitamin K1 to increase with the mother’s age. Moreover, the concentration of MK-4 in mature milk was highest in summer, followed by spring and winter. The levels of vitamin K1 and MK-4 in mature milk were found to be affected by lactation stage; they were highest at 91–120 days and lowest at 31–60 days. Conclusions: Based on the concentration of vitamin K in mature milk found in this study, it is recommended that the appropriate intake of VK for Chinese infants aged 0–5 months is 3.49 μg/d (2.18 μg/d for VK1 and 1.06 μg/d for VK2).