Human milk lipids provide not only energy but also indispensable bioactive components such as essential fatty acids. To establish the recommended daily intake value and guidelines for infant formula, a reference library of fatty acid composition has been generated from 4 Asian countries (South Korea, China, Vietnam, and Pakistan). Regardless of country, palmitic acid (C16:0), linoleic acid (C18:1), and linolenic acid (C18:2) were the 3 most abundant fatty acids in human milk and account for more than 75% of total fatty acids (total FA). However, there were several considerable differences between fatty acids, particularly n-3 and n-6 (omega-3 and omega-6) groups. Chinese mothers' milk had a high concentration of linoleic acid at 24.38 ± 10.02% of total FA, which may be due to maternal diet. Among the 4 countries, Pakistani mothers' milk contained a high amount of saturated fatty acid (56.83 ± 5.96% of total FA), and consequently, polyunsaturated fatty acids, including n-3 and n-6, were significantly lower than in other countries. It is noteworthy that docosahexaenoic acid (DHA) in Pakistani mothers' milk was 44.8 ± 33.3 mg/L, which is only 25 to 30% of the levels in the other 3 countries, suggesting the need for DHA supplementation for infants in Pakistan. Moreover, the ratio of n-6 to n-3 was also remarkably high in Pakistani mothers' milk (15.21 ± 4.96), being 1.4- to 1.7-fold higher than in other countries. The average DHA:ARA ratio in Asian human milk was 1.01 ± 0.79. Korean mothers' milk showed a high DHA:ARA ratio, with a value of 1.30 ± 0.98, but Pakistani mothers' milk had a significantly lower value (0.42 ± 0.12). The fatty acid compositions and anthropometric data of mother (body mass index, age) did not show any correlation. The obtained data might provide information about human milk compositions in the Asian region that could benefit from setting up recommended nutrient intake and infant formula for Asian babies.

Vitamins are the essential elements for human life and, particularly, for infant health. Human milk is the best source of nutrients for newborns, however, the information of vitamins in Asian maternal milk is still limited. In this study, we have collected 580 Asian maternal milk samples from Korea (n = 254), China (n = 137), Pakistan (n = 92), and Vietnam (n = 97). The vitamin concentrations, including vitamin B-groups (8 vitamins), fat-soluble vitamin (retinol, D, E, K) and lutein in the breast milk of were investigated. The concentration of thiamin (B₁), biotin (B₇), and folic acid (B₉) in mother’s milk of four countries were not considerably different, while riboflavin (B₂), pantothenic acid (B₅), and pyridoxine (B₆) level in Vietnam samples were significantly lower than those in other countries. In contrast, retinol (A) and tocopherol (E) were found to be higher levels in Vietnamese maternal milk. Korean and Chinese maternal milk had low concentrations of retinol that may cause vitamin A deficiency in children. However, Chinese mother’s milk was distinguished with a high concentration of lutein. Pakistani mother’s milk was observed as having a significant problem of folic acid (B₉) deficiency. Regardless of the country, vitamin B₁₂, K, and D did not seem to be provided sufficiently through maternal milk. The moderate positive correlations were found between vitamin concentrations in each country and the pooled sample. The data obtained in this study were able to provide vital information to assess the nutritional status of breast milk in Asian countries and contributed to the efforts of ensuring the best nutrition for Asian children.

Cholesterol is one of the functional nutrients in human milk, which is indispensable for infant growth. In this study, the concentration of cholesterol and desmosterol in human milk from four Asian countries (n = 578), including Korea, China, Vietnam, and Pakistan, were investigated. The average cholesterol concentrations of Korea and China were similar ranging between 90.2–91.6 mg/L, but those from Vietnam and Pakistan were higher at 113.8 and 175.7 mg/L, respectively. The relative standard deviations were 31–36%, except for Pakistan (51%), showing a broad distribution of 48 to 612 mg/L. Desmosterol concentrations were similar, ranging between 11.2 and 12.8 mg/L except for Pakistan, which was lower than other countries at 9.4 mg/L. In addition, the cholesterol and desmosterol concentrations during the lactation periods were not significantly different in all four Asian countries. Mothers’ BMI did not significantly impact the cholesterol and desmosterol concentration in maternal milk within the same country.