Fortified milk

Vitamin D is hard to come by in nature, especially if you're a vegetarian or don't eat seafood. Fortunately, certain dietary products that lack vitamin D naturally are fortified with the substance.

Cow's milk, the most common type of milk, is a natural source of calcium, phosphorus, and riboflavin, among other minerals. Cow's milk is fortified with vitamin D in several countries. It typically contains 115–130 IU per cup (237 ml), or 15–22% of the daily value. Because vitamin D is almost exclusively found in animal sources, vegetarians and vegans are more vulnerable to deficiency. As a result, plant-based milk replacements such as soy milk are frequently fortified with this nutrient as well as other vitamins and minerals found in cow's milk. One cup (237 ml) typically contains 107–117 IU of vitamin D or 13–15% of the DV.