Very few foods are natural sources of vitamin D. Fatty fish (mackerel, salmon, sardines) and fish liver oil are among the best sources of vitamin D11.
Vitamin D may also be consumed through fortified foods. Vitamin D fortification of certain dairy products and cereals began in the early 20th century to help eradicate disease such as rickets. Consequently, some cow milks, cow milk substitutes, infant formula, orange juices, breads and cereals may add vitamin D added to support adequate intake of vitamin D.