Getting enough vitamin D from your diet can be a challenge if you’re not much of a milk drinker. That's because dairy milk, which is usually fortified with the bone-friendly nutrient, is one of the few foods that contain D in abundant amounts. But milk alternatives, such as soy milk, almond milk, coconut milk, and rice milk, may be a good option for getting vitamin D, especially now.  

Many milk alternatives are fortified with vitamin D, so they contain almost as much D as cow’s milk. And since the Food and Drug Administration has recently increased the amount of vitamin D that can be added to both dairy milk and milk alternatives, you can now get up to 205 international units (IU) of D in an 8-ounce glass of your favorite dairy substitute. That's almost twice as much as a milk drink could contain before the rule change. (The recommended target is 600 IU per day for adults up to age 70 and 800 IU per day after that.)

“This could really help,” says Kelly Pritchett, Ph.D., R.D., an assistant professor in nutrition and exercise science at Central Washington University in Ellensburg, Wash., and a spokeswoman for the Academy of Nutrition and Dietetics. “Most people don’t get enough D. Fortified foods are the biggest provider in the American diet.” They may be especially important if you rarely get outside in the sunshine, because your body makes D from sunlight. 

But you can't simply assume there’s D in milk alternatives. The Department of Agriculture doesn’t require producers of milk—dairy or otherwise—to fortify it with vitamin D. And while most cow’s milk sold in the U.S. does contain added vitamin D, some milk alternatives don't. So check the Nutrition Facts panel.

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Different Types of Vitamin D

The type of vitamin D added to milk alternatives may differ from what's added to dairy milk. Cow’s milk is fortified with vitamin D3 (cholecalciferol), which is derived from the lanolin found in sheep’s wool. Plant-based milks (and plant-based yogurt) may be fortified with D2 (ergocalciferol), which is produced by irradiating yeast. That may be a plus for those who avoid consuming animal products, researchers say.

Both types seem to be absorbed similarly. A 2012 study from King’s College in the United Kingdom involving people who drank milk fortified with either D2 or D3 found that their blood levels of D rose equally no matter which vitamin D-fortified milk they drank.

Too Much Vitamin D?

If your doctor has recommended a vitamin D supplement—because, for example, you've been found to be deficient—you might be concerned that the new higher levels of fortification might cause you to consume too much of the nutrient.

Over time, say experts, too much D can damage the heart and kidneys. The Institute of Medicine says the safe upper limit for D is 4,000 IU per day. “It’s unlikely that people could exceed that through food alone," Pritchett says, "but if you’re taking a supplement, you might want to look at all of your daily sources.”

Foods that naturally contain vitamin D include fatty fish such as mackerel, salmon, and tuna, along with beef liver, cheese, and egg yolks. When it comes to foods that are fortified with vitamin D, under the new FDA rule, yogurt made from plant-based milks can now also contain up to about 220 IU of added D per 8 ounces. In the past, some types had none. (Cow’s-milk yogurt, which may also be fortified with vitamin D, wasn't included in the recent ruling, and the amount of the vitamin in that product can vary.) Other foods that often have vitamin D added include cereals, calcium-fortified orange juice, and margarine.