Vitamin Information Center

Long-term supplementation with vitamin E and vitamin C may not prevent cancer, according to data from the Physician’s Health Study II that was presented at the American Association for Cancer Research’s Seventh Annual International Conference in Washington, D.C. on November 16, 2008.[1]

The role of diet in cancer incidence remains a major focus among researchers, as it is becoming more evident that diet may reduce the risk of developing certain types of cancers. For example, vitamin D appears to have a protective effect against pancreatic cancer and also colorectal adenomas.[2][3] In addition, several studies have linked vitamin E, selenium, and lycopene with a reduction in prostate cancer. However, it has also been discovered that supplementation with specific vitamins and minerals often does not have the same protective role as obtaining the nutrients from foods. In other words, there is still much to be learned about the role of nutrients in the prevention of cancer.

The Physician’s Health Study II is a large-scale, long-term, randomized clinical trial involving over 14,000 physicians over the age of 50. The physicians were given either a) 400 IU of vitamin E every other day or placebo or b) 500 mg of vitamin C daily or placebo and were then followed for up to 10 years. The primary endpoint of the vitamin C group was the development of cancer. The primary endpoint of the vitamin E group was the development of prostate cancer, with a secondary endpoint being the development of any type of cancer.

After nearly 10 years of supplementation, there was no evidence that vitamin E or vitamin C played a protective role against cancer. Thus far, there have been 1,929 cancer cases in the group, including 1,013 cases of prostate cancer. The researchers concluded that neither vitamin E nor vitamin C offers any beneficial effect against cancer.

Research in this field is ongoing; however, the results from this study indicate that vitamin supplements may not provide the same benefits as vitamins included as part of a healthy, balanced diet.

References:

[1] Buring JE, Sesso HD, Gaziano JM, et al. A randomized factorial trial of vitamins E and C in the prevention of cancer in men: the Physicians’ Health Study II. Proceedings from American Association for Cancer Research Annual Meeting. Abstract #PR-1.

[2] Skinner HG, Michaud DS, Giovannucci E, Willett WC, Colditz GA, Fuchs CS. Vitamin D Intake and the Risk for Pancreatic Cancer in Two Cohort Studies. Cancer Epidemiology, Biomarkers, and Prevention. 2006;15:1688-95.

[3] Wei MY, Garland CF, Gorham ED. Vitamin D and prevention of colorectal adenoma: A meta-analysis. Cancer Epidemiology, Biomarkers and Prevention. 2008;17(11):2958-2969.

ATLANTA, April 14 (UPI) — U.S. researchers say they are learning how vitamins and minerals can stimulate or prevent the development of colon cancer.

Emory University researchers in Atlanta find in a study of 92 patients that supplementing a diet with calcium and vitamin D appears to increase the levels of a protein call Bax — which controls programmed cell death — that may push pre-cancerous cells to self-destruct.

In another, 200-patient, case-control study, led by Dr. Robert Bostick of Emory University, high levels of calcium and vitamin D together are associated with increased levels of E-cadherin, which moderates colon cells’ movement and proliferation.

A third study on the same 200-patients shows high levels of iron in the diet are linked to low levels of APC, a protein whose absence in colon cancer cells leads to their runaway growth.

All three studies — scheduled to be presented at the American Association for Cancer Research meeting in San Diego — use colorectal biopsy samples and are part of a larger effort to identify a portfolio of measurements which taken together could predict the risk of colon cancer.

“We want to have the equivalent of measuring cholesterol or high blood pressure, but for colon cancer instead of heart disease,” Bostick says in a statement.

ATLANTA, April 14 (UPI) — U.S. researchers say they are learning how vitamins and minerals can stimulate or prevent the development of colon cancer.Emory University researchers in Atlanta find in a study of 92 patients that supplementing a diet with calcium and vitamin D appears to increase the levels of a protein call Bax — which controls programmed cell death — that may push pre-cancerous cells to self-destruct.

In another, 200-patient, case-control study, led by Dr. Robert Bostick of Emory University, high levels of calcium and vitamin D together are associated with increased levels of E-cadherin, which moderates colon cells’ movement and proliferation.

A third study on the same 200-patients shows high levels of iron in the diet are linked to low levels of APC, a protein whose absence in colon cancer cells leads to their runaway growth.

All three studies — scheduled to be presented at the American Association for Cancer Research meeting in San Diego — use colorectal biopsy samples and are part of a larger effort to identify a portfolio of measurements which taken together could predict the risk of colon cancer.

“We want to have the equivalent of measuring cholesterol or high blood pressure, but for colon cancer instead of heart disease,” Bostick says in a statement.

HURSDAY March 13, 2008 (Foodconsumer.org) — Vitamin D is more than more important than thought and it can prevent a range of diseases including cancers.  But a new study cautions that just because you live in a Southern state like Arizona does not mean you would get enough vitamin D through exposure to the sun. This is particularly true in blacks and Hispanics.

For the study, Elizabeth T Jacobs from University of Arizona and the Medical University of South Carolina and colleagues tested Arizonian participants of a colorectal adenoma prevention study for their serum vitamin D known as 25 hydroxyvitamin D or 25(OH)D.

They found 55.5 percent of blacks and 37.6 percent of Hispanics were more likely to have deficient 25(OH)D concentrations (<20 ng per mL) in their blood compared to 22.7 percent in non-Hispanic whites.  Sun exposure had a greater effort on 25(OH)D in whites than in blacks and Hispanics.

The researchers concluded that “Despite residing in a region with high chronic sun exposure, adults in southern Arizona are commonly deficient in vitamin D deficiency, particularly blacks and Hispanics.”

The study was published in American Journal of Clinical Nutrition, Vol. 87, No. 3, 608-613, March 2008.