Fish liver oils and the flesh of fatty fish such as tuna, mackerel and salmon are among natural sources of vitamin D-3. Beef liver, egg yolks and cheese also contain very small amounts of vitamin D-3.Continue Reading
Fortified foods and beverages can also serve as a source of vitamin D-3. In the United States, for example, almost all domestically produced milk is fortified with 100 IU of vitamin D per cup. Infant formulas in the United States and Canada are also fortified with vitamin D. However, manufacturers may choose to fortify their products with vitamin D-2 rather than vitamin D-3, so check nutrition labels to be certain.
The human body is capable of producing its own vitamin D-3 when the skin is exposed to direct sunlight. The Office of Dietary Supplements reports that spending between five and 30 minutes in the sun twice a week between the hours of 10 a.m. and 3 p.m allows the body to synthesize enough vitamin D-3 to meet its own needs. The American Academy of Dermatology, however, strongly discourages spending time in the sun to raise vitamin D levels. Instead, it recommends taking a vitamin D supplement, which can be obtained over the counter or with a prescription.Learn more about Nutritional Content