Archive for Wednesday, March 30, 2005

Vitamin D benefits health

March 30, 2005


Q: Isn't vitamin D known as the "sunshine vitamin"? What should I do if I don't get much sunshine?

A: Yes, vitamin D is often referred to as the "sunshine vitamin." New research is revealing that vitamin D has broader effects for human health than originally suspected. For a long time, scientists have known that vitamin D helps the body absorb calcium and phosphorus and promotes the growth of strong bones. New studies show that vitamin D also helps preserve muscle strength and helps protect against deadly diseases including multiple sclerosis, diabetes and even cancer.

Vitamin D is nicknamed the "sunshine vitamin" because once sunlight hits your skin, it starts a chain of events that produces the vitamin. The human body can produce 10,000 to 12,000 international units of vitamin D from a half-hour of summer sun exposure. However, darker skinned people require longer exposure to sunlight to make the same amount of vitamin D -- approximately 3 hours versus about 30 minutes. A study also found that as the human skin ages, it may produce less vitamin D from sunlight. In adults older than 65, there was a fourfold decrease in the body's ability to produce vitamin D.

Many people like you do not get enough vitamin D from sun exposure, especially during the winter. When people limit their sun exposure -- or use sunscreen to help prevent skin cancer -- they also reduce their vitamin D production. The body's production of vitamin D also varies according to the intensity of the sun, as affected by geographical latitude, time of day, and the season.

The amount of dietary vitamin D that is recommended for most adults is 200 to 400 international units. The 2005 Dietary Guidelines for Americans encourage all people exposed to insufficient sunlight, older adults and those with dark skin to consume vitamin D-fortified foods or a daily multivitamin with 400 international units of vitamin D, or both. Some foods, such as fatty fish, fish liver oils and egg yolks from chickens that have been fed vitamin D, contain vitamin D naturally. Other foods, such as milk, some yogurts and breakfast cereals, are fortified with the vitamin.

Here is a list of some common sources of vitamin D foods and the international units of vitamin D that they contain:

1 T. cod liver oil -- 1360 IU

3.5 oz. cooked pacific oysters -- 640 IU

3.5 oz. canned mackerel -- 360 IU

3.5 oz. most fish -- 88 IU

1 cup fortified milk -- 100 IU

1 cooked egg -- 26 IU

3.5 oz. beef -- 7 IU

1 cup yogurt -- 4 IU

Q: Can you consume too much vitamin D?

A: Yes, vitamin D toxicity can occur by consuming too many supplements only. Toxicity cannot occur when vitamin D is formed from sunlight because the body controls the amount formed.

Toxic effects can include calcification of soft tissues, reduced kidney function, and central nervous system disorders.

Q: I'm confused about which foods should be washed and not washed.

A: We usually equate washing with cleanliness. We wash our hands before cooking or eating. We wash our dishes, clothes and even our cars. Some foods should be washed; whereas others should not.

Here are our recommendations:

Meat and poultry: No. Washing or rinsing raw poultry, beef, pork, lamb or veal before cooking is not recommended because it increases the risk for cross-contamination. Washing these foods can allow bacteria that are present on the surface of the meat or poultry to spread to ready-to-eat foods, kitchen utensils and counter surfaces. Some consumers rinse or soak ham, bacon or pork to reduce the salt content. In reality, very little salt is removed from meats by this practice.

Eggs: No. Washing is a routine part of commercial egg processing so eggs do not need to be washed again at home. After eggs are washed during the manufacturing process, a thin coating of edible mineral oil is layered on to protect the egg from bacteria. Extra handling and washing of the eggs could increase the risk of cross-contamination, especially if the shell becomes cracked.

Fresh fruits and vegetables: Yes. Remove and discard outer leaves, if present. Just before eating or preparing fresh fruits and vegetables, rinse under cool running tap water to remove any lingering dirt. This reduces bacteria that may be present. Do not wash fruits or vegetables with detergent or soap because residues from soap or detergent could be absorbed into the food. If there is a firm surface, such as on potatoes or melons, you may wish to scrub it with a clean brush. If storing, dry the fruit or vegetable using clean disposable or cloth towels. When preparing fruits and vegetables, cut away any damaged or bruised areas because bacteria that may cause illness can thrive in those places.

Q: I heard that there is going to be a program on the health benefits of eating fruits and vegetables. Can you tell me more?

A: Connie Detweiler, K-State Research and Extension Family Nutrition Program Assistant in Douglas County, will be presenting a program on "Color Me Healthy" at 9:30 a.m. Friday at the Douglas County Extension Office at the Douglas County Fairgrounds, 21st and Harper. Detweiler will describe the benefits of eating many colors of fruits and vegetables, and discuss which foods are especially good for healthy eating. Resources for fresh produce, selection, handling and preparation also will be shared.

Participants are being asked to prepare and bring a favorite fruit or vegetable dish and the recipe to share with the group. If participants are unable to bring a dish, a $3 fee will be charged at the door.

To preregister for this program, contact K-State Research and Extension-Douglas County at 843-7058.

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