This research evaluated the stability of vitamins and active components under ultra-low temperature conditions in order to provide a basis to formulate the quality standard for breast milk bank to ensure minimal nutrient loss during storage at ?80 ℃. The results showed that vitamin contents significantly reduced with storage time up to 12 months, yet no significant change was observed in nucleotide contents. After 3 months of storage, the contents of VB2 and VA decreased to 35% and 29% of the original level, respectively, while VC was at undetectable level. Moreover, nicotinic acid at the end of storage dropped to 69% of the fresh breast milk. Considering the existing quality indicators, the quality standard for breast milk bank should be based on breast milk components to be analyzed and fresh breast milk should be used as far as possible to analyze ingredients with poor stability such as vitamins.

This investigation determined the contents of the fat-soluble vitamins A, D and E in human milk samples collected from Hohhot, the capital of North China’s Inner Mongolia region, and analyzed the changing patterns of these vitamins during the lactation period. Nutritional evaluation of maternal breast milk with respect to these fat-soluble vitamins was conducted by the Chinese dietary reference intake (DRI) with the aim of guiding the development of milk powder products for infants. The results showed that the contents of VA and VE were 0.11 and 0.93 mg/100 mL in colostrum, and 0.05 and 0.29 mg/100 mL in mature milk, respectively, while VD content was too low to be detected in colostrum and mature milk. VA and VE contents tended to decline with prolonged lactation. Moreover, it was found that VA was relatively abundant in breast milk from Hohhot, which could meet infants’ nutritional requirements. However, breast milk could not meet VD and VE requirements for infants. As a result, dietary fortification and supplementation of VD and VE are needed for breastfed infants.