National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
Key Laboratory of Public Nutrition and Health, National Health Commission of the People's Republic of China, Beijing 100050, China.
Nutrients. 2024 Oct 2;16(19):3351. doi: 10.3390/nu16193351.
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.
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.
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.
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).
本研究旨在了解中国哺乳期母亲成熟乳中维生素 K 的水平，为制定 0-5 月龄婴儿维生素 K 适宜摄入量（AI）提供依据。
采用简单随机抽样方法，从中国母婴队列研究建立的成熟乳库中选取 500 名健康哺乳期母亲。通过问卷调查获得哺乳期母亲及其婴儿的相关信息。采用液相色谱-串联质谱法测定成熟乳中维生素 K1 和维生素 K2（MK-4 和 MK-7）的含量。
成熟乳中维生素 K 的总浓度为 4.50（2.85-6.33）ng/mL。维生素 K1、维生素 K2、MK-4 和 MK-7 的浓度分别为 2.81（1.66-4.39）ng/mL、1.37（0.75-2.11）ng/mL、1.20（0.58-1.97）ng/mL 和 0.13（0.08-0.19）ng/mL，其中维生素 K1 浓度最高，MK-7 浓度最低。南方成熟乳中维生素 K2 和 MK-4 的浓度显著高于北方成熟乳。城区哺乳期母亲成熟乳中总维生素 K、维生素 K2 和 MK-4 的浓度均高于农村。总维生素 K 和维生素 K1 的浓度随母亲年龄的增加而呈上升趋势。此外，MK-4 浓度在夏季最高，其次是春季和冬季。成熟乳中维生素 K1 和 MK-4 的浓度受泌乳期的影响，91-120 天最高，31-60 天最低。
基于本研究中成熟乳中维生素 K 的浓度，建议中国 0-5 月龄婴儿维生素 K 的适宜摄入量为 3.49μg/d（维生素 K1 为 2.18μg/d，维生素 K2 为 1.06μg/d）。
