West K D, Kirksey A
Am J Clin Nutr. 1976 Sep;29(9):961-9. doi: 10.1093/ajcn/29.9.961.
The influence of the level of vitamin B6 intake on the content of the vitamin in milk was studied in 19 healthy subjects whose stages of lactation ranged from 3 weeks to 30 months. Total vitamin B6 intakes, including extra-dietary sources of the vitamin, ranged from 1.3 to 12.5 mg per day with six subjects consuming less than the recommended allowance of 2.5 mg per day (RDA, 1974). Subjects consuming less than 2.5 mg of vitamin B6 per day had significantly less vitamin B6/liter milk (129 mug) than groups consuming 2.5 to 5.0 or greater than 5.0 mg per day (239 and 314 mug, respectively). Among subjects consuming greater than 2.5 mg of vitamin per day the stage of lactation did not influence the levels of protein or vitamin B6 in milk. Vitamin B6 intakes two to five times the recommended allowance did not significantly elevate the level of the vitamin in milk compared to values for subjects whose intakes approximated the allowance. The vitamin B6/protein ratio in milk of subjects consuming less than 2.5 mg vitamin B6 per day was 13 mug/g and was significantly lower than that observed for the other two groups (23 and 28 mug/g). Daily and weekly variations of the vitamin B6 and protein content in milk of individuals were small. However, marked diurnal variations in the vitamin B6 content were found in milk of individuals taking daily supplements of the vitamin with peak levels occurring in the afternoon 3 to 5 hr after supplements were taken in the morning.
在19名哺乳期从3周到30个月不等的健康受试者中，研究了维生素B6摄入量水平对乳汁中该维生素含量的影响。维生素B6的总摄入量，包括该维生素的非饮食来源，范围为每天1.3至12.5毫克，有6名受试者的摄入量低于每天2.5毫克的推荐摄入量（1974年的膳食营养素推荐摄入量）。每天摄入维生素B6少于2.5毫克的受试者，其每升乳汁中的维生素B6含量（129微克）明显低于每天摄入2.5至5.0毫克或高于5.0毫克的组（分别为239微克和314微克）。在每天摄入维生素超过2.5毫克的受试者中，哺乳期阶段并不影响乳汁中蛋白质或维生素B6的水平。与摄入量接近推荐摄入量的受试者相比，维生素B6摄入量为推荐摄入量两到五倍时，并未显著提高乳汁中该维生素的水平。每天摄入维生素B6少于2.5毫克的受试者，其乳汁中维生素B6/蛋白质的比例为13微克/克，明显低于其他两组（分别为23微克/克和28微克/克）。个体乳汁中维生素B6和蛋白质含量的每日和每周变化较小。然而，在每天补充维生素的个体的乳汁中发现了明显的维生素B6昼夜变化，峰值出现在上午补充维生素后下午3至5小时。
