Foods Containing Vitamin D

We all need to focus on obtaining enough vitamin D from food sources, sunshine as well as supplements for maintenance of good health. The current recommended daily intake of vitamin D is 1000IU daily for adults, and 200 IU for infants and children.
Unfortunately, food sources of vitamin D are limited, making it important to understand how to maintain adequate levels of vitamin D. Vitamin D insufficiency and deficiency has lifetime implications toward poor health outcomes. But can you get enough vitamin D from food sources?

Significance

It's difficult to obtain vitamin D from food, yet the vitamin is absolutely essential to well-being. According to estimates, most adults and children do not get enough vitamin D. Recent research suggests that every effort should be made to incorporate sunshine, food sources of vitamin D and vitamin D supplements as an addition to an overall healthy lifestyle.
Historically, inadequate levels of vitamin D are associated with autoimmune disorders, heart disease, osteoporosis, periodontal disease, and cancer. Elders and children are especially susceptible to injury from falls because vitamin D has a strong influence of muscle development and performance.

Function

Vitamin D is a fat-soluble vitamin that requires sunshine for metabolism. Vitamin D is composed of vitamin D2 (ergocalciferol), and vitamin D3 (cholecalciferol). Ultraviolet B rays convert vitamin D7 to D3. Through a series of chemical interactions, the end product that circulates in the body is 25-hydroxyvitamin D. In order to provide the body with benefit, the kidneys must then convert 25-hydroxyvitamin D to its active form, 1, 25-hydroxyvitamin D. Vitamin D is important for the absorption of calcium and phosphorus as it is absorbed by the intestines from the bloodstrea to facilitate calcium absorption into the bones.
When calcium levels are higher in the bloodstream, through dietary intake, and the results of UVB rays, absorption of vitamin D is stimulated, putting it to good use.
Vitamin D is easily stored in fat cells, making obese people more at risk for vitamin D deficiency.

Identification

Vtiamin D deficiency has long been associated with the development of rickets, a disease that causes softening of the bones and bone fracture. It is still one of the most common ailments of children in developing countries. The fortified milk program, developed in the 1930's nearly eliminated the incidence of rickets.
Osteomalacia is a symptom of vitamin D deficiency, initially manifested by muscle weakness and bone pain.
Since vitamin D is necessary for calcium absorption, identifying vitamin D deficiency is important. Low levels of calcium can cause seizures, numbness around the mouth, arms and legs, as well as hand spasms and heart rhythm disturbances.
Frequent fractures from minor trauma may be an indication of vitamin D deficiency in children and adults.

Considerations

The National Institute of Health (NIH) advocates ten to fifteen minutes of direct sunlight, including face, arms, hands or back twice a week to maintain adequate levels of vitamin D. But, that isn't always possible, making food sources important. People who live in upper latitudes are especially in need of consuming vitamin D rich foods in the winter.
Sunscreen is thought to be a contributing factor to vitamin D deficiency, causing a double-edged sword for anyone who is at high risk or with a history of skin cancer fearful of UVB rays.
Tanning beds are not a good option, as they have been found to increase the risk of skin cancer, though their use has been discussed.

Prevention/Solution

Foods containing vitamin D include fortified milk, cereals and oily fish. The best source of vitamin D is fish. caught in the wild versus farm raised. Frying fish has been found to decrease vitamin D content. Mackerel, sardines and salmon are high in vitamin D. Cod liver oil currently on the market has had most of the vitamin D removed. Pure, unrefined cod liver oil contains a 1360 IU's of vitamin D.
Some orange juices are also fortified with vitamin D. Mushrooms are also a good source of vitamin D and an excellent substitute for meat. The only cheese with vitamin D is Swiss cheese. One ounce contains 12 IU of vitamin D.
Lactose intolerant individuals can find vitamin D in fortified soy milk. Canned pink salmon contains approximately, 530 IU of vitamin D, while canned mackerel contains 213 IU's. Canned tuna fish (in oil), contains 200 IU per serving. Quaker Nutrition for Women Instant Oatmeal contains 154 IU of vitamin D -- it's alright for men to eat it, too.
Eat salmon at least three times a week, also recommended by the American Heart Association for the prevention of cardiovascular disease. Not only will your heart benefit, but you'll be supplementing your diet with vitamin D. Again, look for salmon caught in the wild. When choosing fortified cereals, watch the sugar content and other nutrients by reading your labels.

Warning

If you take medications such as anticonvulsants, thiazide diuretics, corticosteroids, nicotine, cimetidine, cholesterol-lowering agents (ezetimibe), heparin, or weight-loss drugs (Xenical and Alli), it's important to know that these medications interfere with vitamin D absorption.
Since food sources of vitamin D really are limited, it's necessary to make a conscious effort to ensure you're getting enough vitamin D on a daily basis. Take a multi-vitamin if you are at risk. Most multivitamins contain 400IU of vitamin D. You might consider taking one vitamin 3 times a day if needed, after discussing with your health care provider. Vitamin D toxicity, though rare, can occur with supplementation of greater than 10,000 IU/day, making them fairly safe.