NEW EVIDENCE ON OLD VITAMIN:
VITAMIN D MAY COMBAT
BREAST, COLON AND PROSTATE CA

From The Cancer Chronicles #32-#33
© June 1996 by Ralph W. Moss, Ph.D.


[NOTE: See the remarks about vitamin D's Anti-angiogenic properties below.
This may have relevance to the flap over angiostatin & endostatin.]

When a Western-style diet that is high in fat but low in calcium and vitamin D is fed to mice, by the eighth week the animals begin to develop precancerous growths in their colons. But if the same mice are then given two sources of calcium these changes are routinely reversed (Richter, et al., Carcinogenesis 1995;16:2685-2689).

Until now, vitamin D has been considered primarily important as a regulator of normal bodily levels (or 'homeostasis') of calcium. But, in addition to its role as a facilitator of calcium absorption, vitamin D now appears to have other profound effects in the body. Moderate amounts of the vitamin may help slow the growth not just colon but breast and prostate cancer, independent of its effect on calcium absorption.

"It's becoming increasingly clear that vitamin D has a host of effects in the body, especially on the growth of tumor cells," David Feldman, MD of Stanford University told a seminar sponsored by the American Institute for Cancer Research in Washington, DC last year.

PROSTATE

For example, intensive work is being done on the link between low vitamin D levels and prostate cancer. In fact, there is a possibility of even using the vitamin to treat the disease. The aforementioned 1,25-D form of the vitamin has induced several important responses in prostate cells, including growth inhibition.

Dr. Feldman and colleagues recently concluded that "vitamin D is anti-proliferative and promotes cellular maturation." It seems clear, they add, "that vitamin D must be viewed as an important cellular modulator of growth and differentiation....Vitamin D has the potential to have beneficial actions on various malignancies including prostate cancer."

1,25-D may prove useful in chemoprevention, they say, and/or in differentiation therapy. They maintain an "optimistic view on the possible use of vitamin D to treat prostate cancer in patients," and say that "further investigation is clearly warranted" (Adv Exp Med Biol 1995;375:53-63).

Recently, new forms (analogs) of vitamin D have been developed that have much less effect on calcium metabolism, but still retain the vitamins tumor inhibiting properties. The action of the vitamin seems to be regulated by a single receptor site, which has the same structure as certain steroid receptors (Niles, RM. Adv Exp Med Biol 1995;375:1-15).

Canadian scientists have reported that in the test tube cancer cell proliferation is "strongly inhibited" by both vitamin D and its analogs. In some systems, they say, the analogs (such as EB1089) were 10 to 100 times more potent than the original compound. This activity "predicts their potential usefulness" in animals in inhibiting squamous cancer growth (Yu. J, et al. Anticancer Drugs 1995;6:101-108)

Prostate cancer is especially prevalent and deadly among African-American men. What could prevent early prostate cancer from progressing to the malignant phase? It has been found that higher serum levels of vitamin D might do this in both Black and white men. This is so especially after the age of 57.

Scientists have concluded that vitamin D metabolism may indeed impact the risk of prostate cancer (Corder, EH, et al., Cancer Epidemiol Biomarkers Prev 1995;4:655-659).

When human prostate cancer cells were implanted into so-called "nude" mice (which are bred to lack a normal immune systems),Vitamin D slowed malignant growth. Several other studies lend credence the idea that vitamin D cancer protect against prostate cancer.

For example, in one study, serum levels of "1,25-D" (the major circulating form of the vitamin) were significantly lower in 181 men who had been diagnosed with prostate cancer, compared to their age-matched controls. The author of that study, Elizabeth Corder, MD, has said that levels of the vitamin could be used as an important way of predicting the risks for prostate tumors.

A study from the University of North Carolina found that men living in northern latitudes are at greater risk of developing prostate cancer. Such men have less exposure to ultraviolet radiation, the principal source of vitamin D in the body. This observations further supports the theory that having lowered levels of vitamin D predisposes men to prostate cancer.

BREAST CANCER

At a meeting of the US President's Cancer Panel Special Commission on Breast Cancer, convened in Reston, Va. on 9/23/92, British scientists David Hunter and Dimitrios Trichopoulos reported on a strong inverse correlation between breast cancer mortality in the US and exposure to ultraviolet sunlight.

Since vitamin D is created by exposure to sunlight, this suggested that low levels of vitamin D plays a part in the onset of cancer (Lancet1992;340:905). In addition, scientists writing in the Cancer Letter analyzed the anticancer effects of vitamin D and four of its analogs on a human breast cancer cell line. Growth of such cells was "significantly inhibited" by all such compounds. These results demonstrate that analogs of vitamin D are "potent antiproliferative agents on human breast cancer cells" (Brenner, RV, et al., Cancer Lett, 1995;92:77-82).

The same researchers also showed that levels of the vitamin were lower in patients with colon cancer than in controls. The mechanism of action is unclear. However, it is known that both calcium and vitamin D can be deterrents to colon cancer. Since the vitamin is necessary for the absorption of the mineral, it seems to be their dual action that halts the proliferation of colon epithelial cells.

MELANOMA LINK

These latest findings support the theory of Drs. Frank C. and Cedra F. Garland. Between 1974 and 1984, they studied 176 cases of melanoma among Navy personnel. After testicular cancer, melanoma is the second most-common cause of cancer in male US Navy personnel (Archives of Environmental Health 1990;45:261-267).

Melanoma is usually associated with excessive exposure to the sun. However, it was found that sailors who had indoor jobs (e.g., on engine crews) actually had an incidence of melanoma that was higher than those who worked outdoors. Those who spent some time outdoors (but not an excess of time) seemed to actually benefit by generating vitamin D from the sun.

The Garlands concluded there may be a protective effect from brief but regular exposure to sunlight. Vitamin D may suppress malignant melanoma.

ANTI-ANGIOGENESIS

Vitamin D and its derivative compounds also have been shown to inhibit tumor growth in mice with a deadly form of eye cancer called retinoblastoma.

In humans, this is a rare cancer, afflicting about 200 individuals per year, most of them children. Until now, the mechanism of vitamin Ds action in this experimental tumor has not been understood. But in 1995, Boston scientists gave these mice either high or low doses of vitamin D in mineral oil by injection, five times per week for five weeks.

The control animals were injected with mineral oil alone. At five months of age, the animals were killed and their eyes processed for analysis by light microscopy.

Mice receiving high-dose vitamin D had formed the lowest numbers of blood vessels in the eye. This was followed by the low-dose vitamin D group. But the control group showed the highest blood vessel countãalmost double that of the first group. The number of blood vessels in this particular animal model is indicative of retinoblastoma.

The scientists concluded that vitamin D could definitely exert anticancer effects through the inhibition of new vessel formation, or angiogenesis (Shokravi, MT, et al., Invest Ophthalmol Vis Sci, 1995;36:83-87). This type of tumor inhibition is "hot" right now. It is not only the basis of the work of some well established scientists (see p. 6) but is a purported mechanism of action for shark cartilage.

TO SUPPLEMENT OR NOT?

While some scientists in Holland recently concluded that there are "insufficient reasons to supplement subjects at increased colon cancer risk with calcium or vitamin D,<especially if they are getting the recommended amounts in their diets (Kleibeuker et al., Eur J Cancer 1995;31A:1081-1084), many others would strongly disagree.

How do we know if a person is truly getting enough vitamin D? Because they drink a lot of milk? It is quite disturbing that the vitamin D content in milk--the major source of the vitamin in the Western diet--may be serious misrepresented.

A report by Tai C. Chen, PhD, of Boston University School of Medicine, and other researchers, found that 80 percent of the milk samples in the U.S. contained either 20 percent less or 20 percent more vitamin D than the label claimed. In fact, fourteen percent of the samples had undetectable amounts of the vitamin (New Engl J Med 1993;329:1507).

Supplements of vitamin D are usually found together with vitamin A. These typically contain 400 IUs of vitamin D. The cost of each such tablet or capsule is between three and five cents. This is a harmless amount to take. It seems to be a very small price indeed to pay for some possibly significant protection against melanoma, prostate, colon, and breast cancer.


Ralph W. Moss, Ph.D. is director of the The Moss Reports for cancer patients. Dr. Moss is the author of eleven books and three documentaries on cancer-related topics. He is or has been an advisor on alternative cancer treatments to the National Institutes of Health, the National Cancer Institute, the American Urological Association, Columbia University, the University of Texas, the Susan G. Komen Foundation and the German Society of Oncology. He wrote the first article on alternative medicine for the Encyclopedia Britannica yearbook. He is listed in Marquis Who's Who in America, Who's Who in the World, Who's Who in the East, and Who's Who in Entertainment (as a film documentarian). This Web site does not advocate any particular treatment for cancer. We urge you to always seek competent medical advice for all health problems, especially cancer. Before consulting our site please read our full Disclaimer statement.



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