Many children drink rice, almond or soy milk instead of cow’s milk for various reasons — lactose intolerance, allergies, taste preference. But now Canadian researchers have found that children who do not drink cow’s milk may have insufficient levels of vitamin D.
In a study published online in the Canadian Medical Association Journal, scientists tracked vitamin D blood levels in 2,831 children under the age of 6. About 10 percent of them drank only milk from a source other than cows.
The researchers controlled for many factors that can affect vitamin D levels — age, sex, weight, vitamin D supplementation, skin pigmentation, hours of outdoor play and other variables. But they still found that children who drank only milk from sources other than cows were almost three times as likely as those who drank only cow’s milk to have vitamin D levels below 20 nanograms per milliliter, a level generally accepted as normal for children.
The senior author, Dr. Jonathon L. Maguire, a pediatrician and researcher at St. Michael’s Hospital in Toronto, said that parents may choose milk not produced by cows believing they are choosing something healthful, but they may not be.
“Cow’s milk is guaranteed to contain vitamin D,” he said, “but with another milk product, that’s not so.”
Among children who drank both kinds of milk, each additional cup of milk consumed from another source was associated with a 5 percent decrease in vitamin D level.