E. - Fat-Soluble Vitamins in Bovine Milk

Abstract

This chapter discusses fat-soluble vitamins in bovine milk. The most recent and best method of analysis, high-performance liquid chromatography (HPLC), has not been used much for the analysis of retinoids, carotenoids, vitamin D, tocopherols, and vitamin K in bovine milk. The older data were obtained mostly by spectrophotometric methods either of the compounds themselves or of a derivative. The retinoids are photo and heat sensitive. Pasteurization reduces the content, but this is not important since most milk is pasteurized and some is fortified. Milk and dairy products can provide substantial amounts of retinoids and carotenoids in the diet. One quart of whole milk contains about 36%–41% of the RDA for an adult male. Bovine milk as secreted is deficient in vitamin D for the needs of humans, particularly for infants and children. Since milk is deficient, it and other dairy products are fortified with 400 lU of cholecalciferol per quart. About one-third of the vitamin D was lost when low-fat milk was stored for 10 days at 4X, presumably because of photoxidation. Bovine milk contains relatively small quantities of tocopherols compared to, for example, human milk. HPLC provides much better resolution, precision, and sensitivity than the older colorimetric method. Vitamin K is difficult to analyze even with the aid of HPLC. More phylloquinone (K1) was found in the milk from Jersey or Guernsey cows (8.7 μg/liter) compared to the Friesian breed (4.9 μg/liter).