A new study found that children who drink non-cow milk alternatives have lower levels of Vitamin D compared to those who regularly consume cow milk.

Non-cow milk, such as rice, almond, soy or goat's milk, has become popular as many people are lactose intolerant and believe there are health benefits associated with drinking a replacement beverage.

Vitamin D is different from other vitamins; the body can produce it with sunlight exposure, but one can also get it from food sources such as eggs, oily fish, and vitamin D fortified milk. Low levels of Vitamin D are associated with higher risks, such as aging bones, aggressive prostate cancer and dementia.

Study author Dr. Jonathon Maguire, a pediatrician and researcher with St. Michael's Hospital, worked with his colleagues in examining the Vitamin D levels in the blood of 3,821 children, ages one to six. About 87 percent of the participants drank cow milk, while 13 percent drank non-cow milk.

The findings revealed that the children who drank non-cow milk had lower levels of Vitamin D.

"Children drinking only non-cow's milk were more than twice as likely to be vitamin D deficient as children drinking only cow's milk," said Dr. Maguire in a news release. "Among children who drank non-cow's milk, every additional cup of non-cow's milk was associated with a five percent drop in vitamin D levels per month."

Maguire recommended that parents should always check the labels when buying non-cow milk to see if it contains Vitamin D. In the United States, cow milk products are required to contain at least 40 units of Vitamin D, while it is only voluntary on non-cow milk products. He also reminded pediatricians and healthcare providers to inform parents of the risk when prescribing non-cow milk products to those who have a milk allergy.

"I think on our end as physicians, children who can't drink cow's milk or parents who choose non-cow's milk for their children need to be reminded that their vitamin D levels are probably lower than other children," Maguire said in a phone interview with Reuters.

The study was published in the Oct. 20 issue of the Canadian Medical Association Journal.