Milk may have more than you bargained for - some low-fat milk carried across state lines must have vitamin A and D replaced. Minute amounts of fish oil with these vitamins may be added without vegetarians detecting and avoiding it - Brief Article

Vegetarian Times, Nov, 1996

IS THERE SOMETHING fishy in that glass of milk? Possibly, especially if it's the low-fat or nonfat kind, which can contain fish oil extracts.

Almost all dairy processors voluntarily add vitamin D to milk to make calcium easier to assimilate. And in the case of low-fat or skim milk that's transported across state lines, processors must, by law, also fortify their product with vitamin A and D lost when butterfat is removed. In order to replace fat soluble A and D, some use either a very small amount of fish oil or corn oil, depending on which is cheaper and more available. But Sid Barnard, a professor of food science at Pennsylvania State University, says the amount is so minute it's barely detectable: about 400 IU of oil to 30,000 IU of milk--that's about one cup of fish oil for every 800 gallons of milk.

Vegetarians who want to know which dairies are using halibut- and shark-oil extracts (the most common additives) aren't likely to get much satisfaction. The National Dairy Council, the American Dairy Science Association and even the National Fish Meal and Oil Association said they couldn't identify which dairies use fish oil in milk processing, though none denied the practice. There's not much a consumer can do except check with individual companies, says Artemis P. Simopoulos, M.D., president of the Center for Genetics, Nutrition and Health, a Washington D.C.-based organization that monitors health and science trends. She says even people who claim to be allergic to fish won't have much of a case, because fish oil isn't an allergen:

Last summer a U.S. District judge in Boston banned a television ad exposing the fish-oil furor. The ad, made by H.P. Hood Inc. to target rival Garelick Farms, featured an eyedropper of yellow oil being squirted into a glass of milk. "If you like fish in your milk, Garelick is the natural choice," the announcer intoned. But because the milk neither smelled nor tasted like fish, the judge demanded that Hood scrap plans, to air the ad, saying it was misleading.