Dietary intake and food sources of one-carbon metabolism nutrients in preschool aged children

Background: It is hypothesised that epigenetic mechanisms including DNA methylation may underlie the relationship between early-life nutrition and child cognitive outcomes. This study aimed to identify dietary patterns associated with the intake of one-carbon metabolism nutrients in children aged 2-3 years. Methods: A validated 120-item semi-quantitative food frequency questionnaires at 2-3 years of age were used to estimate the intake of one-carbon metabolism nutrients (methionine, folate, choline and vitamins B2, B6, B12) and to quantify mean number of serves consumed of the food groups specified by the Australian Guide to Healthy Eating (AGHE). Descriptive statistics were used to analyse the contribution of each food group and food items to the total intake of one-carbon metabolism nutrients. Linear regression was used to test for linear trends in food group servings by nutrient intake quintiles. Results: No child (n = 60) from the Women And Their Children's Health (WATCH) study consumed the recommended number of serves for all AGHE food groups. Dairy and alternatives (18-44%), discretionary foods (6-33%) and meat and alternatives (6-31%) were the main sources of most one-carbon metabolism nutrients. Most child intakes of one-carbon metabolism nutrients exceeded the nutrient reference values (NRVs), except for the intake of choline, for which the mean intake was 9% below the adequate intake (AI). Conclusion:: Dairy and alternatives, discretionary foods and meat and alternatives food groups contributed significantly to the children's intake of one-carbon metabolism nutrients. The children generally had low intakes of meat and alternative foods, which may explain their inadequate intake of choline.