A study reported in the Canadian Medical Association Journal this month contains information on 2,831 children in Toronto who had Vitamin D tests. The study found that children who do not predominantly drink cow's milk were more likely to have low Vitamin D levels than children who did.
Of the children, 87 percent drank cow's milk as their primary milk source while the other 13 percent predominantly drank something else as milk, usually a milk substitute from soy or similar. On the whole, Vitamin D levels were lower with children who drank milk substitutes. The study's findings suggest that this could be due to a misunderstanding about what is contained in most milk substitutes.
Non-cow's milk options are not required by either the United States or Canada to have Vitamin D added. Many consumers are likely unaware that many cow's milk substitutes do not contain Vitamin D additives, the researchers said. They found that low Vitamin D levels in the 11 percent of non-cow's milk drinkers (compared to just 5 percent in cow's milk drinkers) were generally due to the substitute being low in Vitamin D.
This study corresponds with a growth study done along a similar vein, which we reported here. Both studies are of interest to parents of children with cow's milk allergies or intolerance.