A survey of vitamin A and D contents of fortified fluid milk in Ontario.

High performance liquid chromatographic methods for measuring the concentration of vitamins A and D in fluid milk were validated and used to assess the level of these nutrients in Ontario retail milk samples. Thirteen and fifteen fortified milk samples were tested for vitamins A and D, respectively. Repeatability relative standard deviation values for vitamins A and D in milk were generally less than 10%. Recoveries varied from 87 to 107%. Vitamin D results indicated that only 20% of skim, 40% of 2% fat milk, and 20% of whole milk contained the recommended levels, whereas 46% of skim, and 77% of 2% fat milk had the required levels of vitamin A. The results indicate that vitamin level varies widely in Ontario retail milk.