Foods with Vitamin D
A long time ago, before most humans worked indoors, we received most of our vitamin D building blocks from the sun. As time went on and we lathered on sunblock and avoided the outdoors, we had to seek out vitamin D. While supplements can be taken to attempt to make up the difference, there is nothing like getting the vitamin straight from the source.
What is Vitamin D?
Vitamin D is actually a group of pro-hormones that are fat-soluble, the two major forms of which are vitamin D2 and vitamin D3. Vitamin D helps regulate phosphorous and calcium levels in blood by facilitating their absorption from food in the intestinal area and reabsorption in the kidneys. Vitamin D also encourages the immune system to release phagocytosis, immunomodulatory functions and anti-tumor activity. Vitamin D deficiencies lead to problems such as impaired bone mineralization and related diseases such as rickets in children and osteomalacia in adults, as well as the potential of osteoporosis.
Foods with Vitamin D
Many foods have been fortified with vitamin D to prevent deficiencies, including milk, yogurt, margarine, breakfast cereal, bread and pastries. Fish liver oils, such as cod liver oil, contain 1,360 IU in each tablespoon. Herring contains 1383 IU in each 3-ounce serving. Catfish, another fatty fish species, has 425 IU per 3-ounce serving. Salmon and mackerel both contain about 350 IU per 3.5-ounce serving. An entire egg has 20 IU of vitamin D, cooked beef liver (3.5 ounces) has 15 IU, and UV-irradiated mushrooms provide a negligible amount.
Recommendations
The human body naturally produces vitamin D when exposed to direct sunlight, but those who can't get sunlight, older adults and those with dark skin are recommended to take about 25 micrograms (1,000 IU, or international units) of vitamin D per day. The typical American diet does not come close to the recommended 1,000 IU per day. As of August 2009 the stated adequate intake level for infants to age 50 is 200 IU per day.
Health Benefits
Recent studies have shown vitamin D to have even more health properties than originally thought. There is speculation that the vitamin has promise in reducing the chances of pancreatic and breast cancer, cardiovascular disease and diabetes. It also may improve infertility, memory and weight control.
