Intakes and sources of Vitamin K₁ in Irish pre-school children aged 1–4 years

Abstract

Vitamin K 1 has a key role in blood coagulation, bone metabolism and the regulation of calcification (1) . There are currently insufficient data available to set an average requirement for vitamin K 1 for children however the European Food Safety Authority (EFSA) has recently proposed an Adequate Intake (AI) of 1·0 µg/kg bodyweight per day based on observed intakes (1) . Few data are available on vitamin K 1 intakes in young children. The objective of this analysis was to estimate the intake and sources of vitamin K 1 in Irish pre-school children aged 1-4 years (n = 500) using data from the Irish National Pre-School Nutrition Survey (2010-2011) (www.iuna.net). Dietary intake data were collected using a 4d weighed food record and the vitamin K 1 content of foods was primarily determined using data from the UK food composition tables (COFID) (2) . For certain foods where vitamin K 1 values were not available in COFID, the US (3) and Danish food composition tables (4) and published papers were used to assign suitable vitamin K 1 values. The vitamin K 1 content of composite dishes and retail products were calculated based on their ingredients. Usual intakes of vitamin K 1 were calculated via the NCI-method (5) using SAS Enterprise Guide. Body weight (kg) was measured in the participants' homes by trained researchers. Differences in vitamin K 1 intakes were assessed using a Kruskal-Wallis test (for non-normal data) and a Wilcoxon two sample test was used for post-hoc analysis. The mean daily intakes of vitamin K 1 were 33, 30, 28 and 32 µg for 1, 2, 3 and 4 year olds, respectively. Adjusted for bodyweight, intakes (μg/kg/d) were 2·9, 2·1, 1·8 and 1·8 respectively showing a decrease (p < 0·001) with increasing age from age 1y to 3-4y respectively. Approximately 82 % of children had intakes above the AI of 1·0 µg/kg bodyweight per day. The table below reports the contribution (%) of food groups to vitamin K 1 intake in Irish children aged 1-4 years, by age.The main source of vitamin K 1 for all ages was 'vegetable and vegetable dishes' (24-32 %, range across age), of which 13-20 % came from green vegetables. Other important sources were fruit & fruit juices (15-17 %), meat (10-11 %) and milk (6-25 %). The contribution from milk decreased significantly (p < 0·001) with increasing age from age 1y to age 3-4y primarily due to consumption of fortified infant and child formula in the earlier years (6)