Could sipping soy, almond or rice milk shortchange kids’ nutrition? A new study from St. Michael’s Hospital in Toronto finds that young children who drink only nondairy milk are twice as likely to have low levels of vitamin D compared to kids who drink cow’s milk.

Researchers found the gap when they checked the milk consumption and vitamin D levels of 2,831 children ages 1 to 6. Their discovery is important as more and more families are choosing nondairy milks for kids (and adults) with milk allergies or lactose intolerance or because they follow vegan diets, says Toby Smithson, MS, RDN, a spokesperson for the Academy of Nutrition and Dietetics.

Sales of nondairy milks are rising. And new varieties — milks made from cashews, coconut, hemp, oats and potatoes — are hitting store shelves. Smithson’s advice for choosing one that gives kids the nutrients they need? “Try to choose plant-based milk alternatives that closely match cow’s milk” in terms of their nutrition. “One cup of cow’s milk generally provides 300 milligrams of calcium and 100 IU of vitamin D.”

Kids and adults need vitamin D and calcium to build and maintain strong bones, regulate blood pressure and maintain good health. Here’s how you can ensure that kids who sip nondairy milks get the right levels of important nutrients.

Know what they need. The National Institutes of Health recommends the following for kids each day:

  • Ages 1-18: 600 IU of vitamin D
  • Ages 1 to 3: 700 milligrams of calcium
  • Ages 4 to 8: 1,000 milligrams of calcium
  • Ages 9 to 18: 1,300 milligrams of calcium

Choose fortified nondairy milks. Top-selling brands of soy, rice and almond milk that are fortified with calcium and vitamin D deliver levels of these nutrients on par with cow’s milk. In fact, some provide extra calcium. Homemade and non-fortified dairy alternatives have less calcium and very little to no vitamin D.

Read the ingredients list. Look for calcium carbonate and tricalcium phosphate. The calcium in nondairy milk may be better absorbed when it comes from those sources, suggests a Purdue University study of soy milk.

Replace protein. “Cow’s milk is a good source of protein, so be aware of receiving less protein when choosing a plant based milk,” Smithson notes. “Soy milk usually contains 2 to 4 grams of protein per serving and many of the brands of almond milk… only provide 1 gram of protein per serving. In contrast, cow’s milk provides 8 grams per 1 cup serving.” Make sure kids get enough protein from other sources, such as beans, tofu, fish or chicken, she suggests.

Watch the sugar. Unsweetened nondairy milks may contain natural sugars, as does milk. But many nondairy milks also have added sweeteners for better flavor. The best way to find it: Check the ingredients list for words like sugar, syrup, cane juice and evaporated corn sweetener. 

Sari Harrar is an award-winning health, medicine and science journalist whose work appears in Dr. Oz The Good Life magazine, Good Housekeeping, O--Oprah Magazine, Organic Gardening and other publications.