eileen

The doctor writes about ... Benefits of vitamin D

September 26, 2007
Doris Montgomery, MS, RD, LD, is the director of the Iowa Nutrition Network at the Iowa Department of Public Health. The network empowers low-income Iowa families to eat a healthful diet and to be physically active.

Montgomery writes:

Health professionals are taking another look at vitamin D. My interest in this topic was piqued recently when a routine bone density scan and blood test showed that I was vitamin D-deficient. Dietitians should not be "deficient." As I tried to figure out what I should do, I realized that I had not kept up with the latest information on vitamin D.

Q: Why should you care about vitamin D?

A: Vitamin D is well-known for its role in bone health, but it does much more. There is growing evidence that vitamin D may help prevent common cancers, such as breast, colon and prostate cancer. Vitamin D may also ward off autoimmune, infectious, and cardiovascular diseases. Although the evidence is still emerging, it is clear that vitamin D deficiency is more common than previously thought. In fact, many experts believe we are facing an epidemic.

Q: What is vitamin D and why is it called the "sunshine vitamin"?

A: Vitamin D functions as a hormone in our bodies. A main function of this hormone is to allow more calcium and phosphorous to be absorbed - thus the strong link to bone health. Without vitamin D, only 15 percent of dietary calcium can actually be absorbed.

Vitamin D is found in very few foods. Fortunately, our bodies have an amazing ability to manufacture vitamin D in our skin after exposure to sun. Ten to 15 minutes of sun exposure without sunscreen at least twice a week to the face, arms or hands is enough to produce adequate amounts of vitamin D. The strength of the sun can make a difference, however. Sun rays in Iowa are probably strong enough in spring, summer and fall, but not in winter.

Sunscreens with a sun protection factor of 8 or greater effectively block ultraviolet rays that produce vitamin D, but it is still important to use sunscreen to help prevent skin cancer and other negative consequences of excessive sun exposure.

The high melanin content in darker skin reduces the skin's ability to produce vitamin D from sunlight. It is important for groups such as African-Americans, people with limited exposure to sun, and the elderly (who are not able to produce sufficient vitamin D) to take vitamin D supplements as well as consume excellent dietary sources of vitamin D.

Q: How much vitamin D is needed for good health?

A: Most vitamin D experts agree that without adequate sun exposure, children and adults require approximately 800 to 1,000 international units, or IU, each day. Older adults, those with darker skin, and people who are not exposed to the sun should include at least 1,000 IU a day from supplements and food sources.

Because of mounting evidence that higher blood levels are associated with greater health benefits, vitamin D experts from around the world are pressuring governments to revise vitamin D recommendations.

Q: Who is at risk of being vitamin D-deficient?

A: Deficiencies have been documented in all age groups from children to older adults. The elderly, individuals with dark skin, and those who avoid sunlight exposure are particularly at risk because their skin does not produce adequate amounts of vitamin D.

People who do not consume foods that contain vitamin D are also at risk.



Q: How do you know if you are vitamin D-deficient or insufficient?

A: There is no consensus on optimal levels of vitamin D. Nevertheless, your physician can order a blood test to measure 25-hydroxyvitamin D, a form of vitamin D that reflects your overall vitamin D status.



Q: Is all milk fortified with vitamin D?

A: Most large, processing plants fortify milk with vitamin D. This only applies to fluid milk, not to milk products such as yogurt, cheese, or ice cream. If you buy milk from a small "on-farm" processor in Iowa, it is likely the milk has not been fortified with vitamin D. Be sure to read the nutrition facts on the label. The amount of vitamin D in fortified milk can vary, so it is best to get vitamin D from a variety of sources.

Q: Is vitamin D available as a supplement?

A: A variety of multivitamin and calcium supplements contain either 200 IU or 400 IU of vitamin D. Over-the-counter individual supplements of vitamin D are available in the range of 400 to 2,000 IU per capsule or tablet. Supplements contain either D3 or D2, but the D3 form is the more potent form and has a greater effect on improving vitamin D status. Read labels to find one that specifies D3, or cholecalciferol, as an ingredient. If you are identified as being vitamin D-deficient based on a blood test, your doctor may prescribe a higher dose of vitamin D.

SOURCE: http://desmoinesregister.com/apps/pb...73/-1/SPORTS09

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under-exposure to uv rays is as dangerous as over-exposure...This is "D" life! (eileen)