Sunshine Vitamin: Vitamin D

Sunshine Vitamin by Rie Wilson

Vitamin D regulates not only bone formation, but also many other different genes including cellular defenses. Recent series of studies show vitamin D has protective effects against cancers, autoimmune conditions and infectious diseases. It's involved in a cell's energy management and self-detoxification. Vitamin D can be obtained from food sources and dietary supplements, as well through a chemical reaction in the skin when it is exposed to UVB light. Evidence suggests the amount of exposure to UVB is connect to risks for developing these illnesses. Using vitamin D as preventative medicine and the treatment of disease is suggested for a range of new therapeutic uses. UVB is the major source to generate vitamin D production by our skin, but vitamin D deficiency is very common. The amount of UVB exposure differs in latitude, season and by ethnicity (people with darker skin have more protection against damage from the sun's rays, but also need stronger light or longer exposure to manufacture vitamin D). As well, increased public awareness of skin damage from excessive exposure to sunlight has increased use of sunblock lotions, and causes a lack of vitamin D production in the body.

The recommended daily intake of vitamin D for adults in North America and Europe ranges between 200IU and 600IU, but some researchers recently concluded the RDIs are inadequate and at least 1,000 IU should be taken to meet a healthy level. Although vitamin D supplements could be taken, toxic vitamin D overdose may be possible. On the other hand, sunshine synthesized vitamin D toxicity has never been observed, and 10,000 IU of vitamin D could be induced by as little as 15-20 minutes of sun exposure (longer sun exposure could degrade the vitamin). Even though vitamin D is a very important substance to treat illnesses and maintain health, we can't dismiss the risk factor of skin damage from sun exposure.

In the research of "An Estimate of Cancer" by Sunlight, Nutrition and Health Research Center, proposes “providing 1,000 IU of vitamin D per day for all adult Americans would cost about $1 billion; the expected benefits for reduction in some cancers would be in the range of $16-25 billion in addition to other health benefits of vitamin D.”

There are benefits to supplements and UVB exposure, however we should consider the risk factors and find alternative ways to satisfy the recommended daily intake. Vitamin D found in foods is well within the safe limits.

Here are some examples of food high in vitamin D.
Cod liver oil, 1 tablespoon 1,360 IU
Salmon, cooked, 3.5 ounces 360
Mackerel, cooked, 3.5 ounces 345
Tuna fish, canned in oil, 3 ounces 200
Sardines, canned in oil, drained, 1.75 ounces 250
Milk, nonfat, reduced fat, and whole, vitamin D-fortified, 1 cup 98
Margarine, fortified, 1 tablespoon 60
Ready-to-eat cereal, fortified with 10% of the DV for vitamin D, 0.75-1 cup (more heavily fortified cereals might provide more of the DV) 40
Egg, 1 whole (vitamin D is found in yolk) 20
Liver, beef, cooked, 3.5 ounces 15
Cheese, Swiss, 1 ounce 12

More about vitamin D
Link to CDC

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