A Survey of the Vitamin and Mineral Content in Milk from Yaks Raised at Different Altitudes.

In this study, the content of vitamins and of toxic and beneficial (macro- and micro-) minerals in milk from yaks raised at different altitudes (3,215, 4,340, and 5,410 m) was investigated. For comparison, the components in cow's milk were also measured. At higher altitudes, a significant ( P < 0.05) increase in vitamin A and vitamin E was observed in the yak's milk, whereas the opposite was observed for vitamin B 1 and vitamin B 2 . No significant statistical difference in vitamin C, Ca, P, Na, K, and Mg concentrations was observed in milk from yaks raised at different altitudes. The concentrations of Zn in milk from yaks raised at different altitudes showed no statistical difference, whereas the Mn and Fe concentrations in milk from yaks raised at 3,215 m were lower than those raised at higher altitudes. The concentrations of Pb and Cd in yak's milk did not exceed the maximum permissible concentrations (Codex Alimentarius Commission), whereas their concentrations were higher in milk from yaks raised at 3,215 m than at higher altitudes. These findings indicated that the contents of vitamins and minerals in yak milk varied in different altitudes.