Manufactured foods fortified with vitamin D include some fruit juices and fruit juice drinks, meal replacement energy bars, soy protein-based beverages, certain cheese and cheese products, flour products, infant formulas, many breakfast cereals, and milk.
In 2016 in the United States, the Food and Drug Administration (FDA) amended food additive regulations for milk fortification, stating that vitamin D levels not exceed 42IU vitamin D per 100g (400IU per US quart) of dairy milk, 84IU of vitamin D per 100g (800IU per quart) of plant milks, and 89IU per 100g (800IU per quart) in plant-based yogurts or in soy beverage products. Plant milks are defined as beverages made from soy, almond, rice, among other plant sources intended as alternatives to dairy milk.
While some studies have found that vitamin D raises 25(OH)D blood levels faster and remains active in the body longer, others contend that vitamin D sources are equally bioavailable and effective as D for raising and sustaining 25(OH)D.