Good reasons for high risk women to up Vitamin D intake

saluki

FREMONT, Calif., Oct. 19 -- Sunlight with its stimulation of vitamin D production may help reduce the risk of regional or distant metastastic breast cancer in light-skinned women, investigators here reported.

Increasing sun exposure almost halved the risk of advanced breast cancer in women with light-pigmented skin, Esther M. John, Ph.D., of the Northern California Cancer Center, and colleagues, reported online in the American Journal of Epidemiology. The protective effect of sunlight did not extend to darker-skinned women or to early-stage breast cancer.

"If confirmed by other studies, our finding of a decreased risk for advanced but not localized cancer cases has significant public health implications," the authors concluded. "In particular, if sun exposure reduces the risk of tumor progression, vitamin D could be recommended for women diagnosed with localized breast cancer."

Experimental data indicate that 1,25-dihydroxyvitamin D, the active form of vitamin D, induces differentiation and apoptosis and inhibits invasion and metastasis in breast and other cells, the authors noted. These effects are mediated by the vitamin D receptor, which is expressed in breast and other tissues.


Polymorphisms in the vitamin D receptor gene may affect the expression or function of receptor protein. Dr. John and colleagues examined associations between breast cancer, sun exposure, and vitamin D receptor gene polymorphisms.

The study population was made up of 1,788 Hispanic, African-American, and non-Hispanic white women ages 35 to 79 with newly diagnosed breast cancer and 2,129 women without breast cancer.

Investigators used a portable reflectometer to measure skin color on the forehead and the underarm, an area usually not exposed to sunlight. Sun exposure was defined by the difference in skin color between the forehead and the underarm. Natural skin color was defined as light, medium, or dark on the basis of underarm reflectometry results.

Biospecimens for genotyping were obtained from 814 cancer patients and 910 women in the control group.

Comparison of reflectometry results in cancer patients and controls showed that a high sun exposure index significantly reduced the risk of advanced breast cancer in light-skinned women (odds ratio 0.53, 95% confidence interval 0.31 to 0.91). The association was limited to advanced cancer and did not vary by vitamin D receptor genotype.

The investigators found no associations between sun exposure and breast cancer risk in women with medium or dark skin pigmentation.

Primary source: American Journal of Epidemiology
Source reference:
John EM et al. "Sun exposure, vitamin D receptor gene polymorphisms, and breast cancer risk in a multiethnic population." Am J Epidemiol 2007;epub.
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Source: American Society of Anesthesiologists (ASA) Released: Wed 26-Sep-2007, 00:00 ET

Vitamin D Inadequacy May Exacerbate Chronic Pain
VITAMIN D INADEQUACY CHRONIC PAIN PAIN MANAGEMENT
Approximately one in four patients who suffer from chronic pain also have inadequate blood levels of vitamin D, possibly contributing to their ongoing pain, according to a new study at the American Society of Anesthesiologists 2007 Annual Meeting in San Francisco.

Newswise — Approximately one in four patients who suffer from chronic pain also have inadequate blood levels of vitamin D, possibly contributing to their ongoing pain, according to a new study. Patients lacking sufficient vitamin D also required higher doses of morphine for a longer period of time.

Researchers recorded the serum vitamin D levels of 267 adults undergoing outpatient treatment for chronic pain, as well as their pain medication (morphine) dose and duration of use, and physical and general health functioning.

Of the patients tested, 26 percent had vitamin D inadequacy. Among these patients, the morphine dose was nearly twice that of the group with adequate vitamin D levels. In addition, the vitamin D inadequacy group used morphine for an average of 71.1 months versus 43.8 months. The vitamin D deficient group also reported lower levels of physical functioning and had a poorer view of their overall health.

It has long been known that inadequate levels of vitamin D can cause pain and muscle weakness, according to the study author, W. Michael Hooten, M.D., medical director, and anesthesiologist at Mayo Comprehensive Pain Rehabilitation Center, Rochester, Minnesota. Previous studies also have suggested that pain-related symptoms of vitamin D inadequacy respond poorly to pain medications.

However, “this is the first time that we have established the prevalence of vitamin D inadequacy among a diverse group of chronic pain patients,” Dr. Hooten said.

“The implications are that in chronic pain patients, vitamin D inadequacy is not the principal cause of pain and muscle weakness, however, it could be a contributing but unrecognized factor,” Dr. Hooten said.

Vitamin D inadequacy can be “easily and inexpensively” treated “with essentially no side effects” using a prescription supplement, once or twice a week for four to six weeks, Dr. Hooten said. Further study is needed to determine whether treating inadequate vitamin D levels will result in improvements to the overall general health for patients with chronic pain.

Founded in 1905, the American Society of Anesthesiologists is an educational, research and scientific association with 41,000 members organized to raise and maintain the standards of the medical practice of anesthesiology and improve the care of the patient. Visit our Web site at http://www.asahq.org.

    

LAphoenix

Susie,

Thanks for posting these articles!  I was curious about the first one in particular, as I'm fair-skinned and Stage III, and wondered whether I should be sitting out in the sun more . . .  I found the following additional info in the USC cancer center's report on the same findings:

The researchers stressed that sunlight is not the only source of vitamin D, which can be obtained from multivitamins, fatty fish and fortified foods such as milk, certain cereals and fruit juices.

Women should not try to reduce their risk of breast cancer by sunbathing because of the risks of sun-induced skin cancer, they said.

"If future studies continue to show reductions in breast cancer risk associated with sun exposure, increasing vitamin D intake from diet and supplements may be the safest solution to achieve adequate levels of vitamin D," said Gary Schwartz, a co-researcher from the Comprehensive Cancer Center at the Wake Forest University School of Medicine.

Sue Ingles, a co-researcher from the Keck School of Medicine of USC, said, "Since many risk factors for breast cancer are not modifiable, our finding that a modifiable factor, vitamin D, may reduce risk is important."

The researchers compared 1,788 breast cancer patients in the San Francisco Bay area with a matched control group of 2,129 women who did not have breast cancer. They included non-Hispanic white, Hispanic and African-American women, thus women with a wide range of natural skin color and a wide range of capacity to produce vitamin D in the body.

Skin color is an important factor that determines how much vitamin D is produced in the body after sun exposure. Dark-skinned individuals produce up to 10 times less vitamin D than light-skinned individuals for the same amount of time spent in the sun. People with darker skin also are more likely to be vitamin D deficient than people with lighter skin.

The research team included Wei Wang of the Keck School. The work was supported by grants from the National Cancer Institute and the U.S. Department of Defense Medical Research Program.

Amy

Brendatrue

Susie--

Thanks for the info. I have been diagnosed recently with low Vit D, and I have tried to increase my sun exposure. Now I will have extra motivation to do so. I also take Cod Liver Oil capsules 3 x day, per my MD's advice, in addition to the D that's in my daily vit/min and my calcium supplement. I was told that you also can receive injections but my MD recommended the Cod Liver Oil approach. I am hopeful....

Brenda