TWISTING THE RECORD ON VITAMIN D

[Guest guest]

TWISTING THE RECORD ON VITAMIN D

A team of researchers led by National Cancer Institute (NCI)

epidemiologist Dr. Michal Freedman has published an article suggesting

that vitamin D is highly successful in reducing deaths from cancers of

the colon and rectum. The researchers studied 16,818 people who had

joined a nationwide U.S. government health survey between 1988 and 1994.

The volunteers were then followed through the year 2000, by which time

536 had died of cancer. The study found that people with relatively high

blood levels of vitamin D when they entered the study had a 72 percent

reduction in their risk of dying of colorectal cancer compared to those

with lower levels of vitamin D.

The article was published in the Journal of the National Cancer

Institute in early November 2007 (although news of it broke a week

earlier). The researchers were quoted as saying that the findings in

colorectal cancer were consistent with other studies of vitamin D. On

the other hand, the study did not establish a more generalized link

between high levels of vitamin D and a reduction in the overall risk of

dying from various cancers, including those of the lung, prostate, and

breast.

There are important questions about the methodology used in this study,

issues that may have limited the researchers' ability to detect some of

the positive effects of vitamin D. But even if the methodology and

conclusions of the Freedman study were correct, it is not so much the

results that are disappointing, but the spin that the mainstream media

put on the findings. The reaction of the media to the study revealed in

a stark way their deeply ingrained prejudice against nutritional

solutions to cancer.

The Reuters news agency did report the study correctly and with a

properly nuanced understanding of its positive and negative aspects. The

headline of the Reuters report read: " Vitamin D Cuts Colon Cancer Death

Risk. " The article, by writer Will Dunham, began: " People with higher

vitamin D levels are less likely to die of colorectal cancer,

researchers said on Tuesday, but the vitamin does not appear to affect

the chances of dying from any other type of cancer " (Oct 31, 2007). This

is a fair summary of the paper's conclusions. One other source, the

Canadian Broadcasting Corp., or CDC, also got it right: " Vitamin D Cuts

Colorectal Cancer Risk. "

But most news outlets that I saw emphasized the negative aspect of the

findings, that vitamin D, as one put it, was no " magic bullet " for

cancer (as if anyone said it was). Here are some of the headlines of

stories that were published hours after the news of the study first

broke:

a.. " Vitamin D May Not Reduce Cancer Deaths " (AP)

b.. " Vitamin D May Not Lower Risk of Cancer Deaths " (Fox)

c.. " Vitamin D Is Not Magic Bullet for Cancer " (Wired News)

d.. " Vitamin D Won't Help Prevent Most Cancers " (HealthDay)

e.. " Vitamin D Doesn't Prevent Cancer Deaths " (Windsor Star)

f.. " Vitamin D Benefit At Issue " (Ft. Worth Star)

g.. " No Connection Found Between Vitamin D and Overall Cancer Deaths "

(Medical News Today)

h.. " Vitamin D Doesn't Reduce Cancer Risk " (Nutraingredients.com)

i.. " Vitamin D Does Not Reduce Overall Cancer Mortality " (ANI India

News)

j.. " Vitamin D Has No Effect on Overall Cancer Death Rate " (Medical

News Today, 2nd article)

k.. " Study Raises Questions About Vitamin D and Cancer " (KWWL Iowa)

l.. " Vitamin D Downgrade As Scientists Advise There is No Real Proof

It Fights Cancer " (Daily Mail)

According to the study, " Colorectal cancer mortality was inversely

related to serum 25(OH)D level. " (Serum 25(OH)D is a standard

biochemical marker that is used to determine blood levels of vitamin D.)

Participants in the study who had 25(OH)D levels of 80 nmol/L or higher

had a 72 percent risk reduction in colorectal cancer compared to people

who had levels lower than 50 nmol/L (Freedman 2007).

A Thought Experiment

So let us now imagine that everyone who had vitamin D levels of 50

nmol/L could be brought up to the level of 80 nmol/L. This could be

accomplished through the judicious use of vitamin D supplements. Another

way would be through increased sunlight exposure, although that is

controversial since it might also raise the risk of some skin cancers.

The American Cancer Society anticipates that in 2007 a total of 52,180

Americans will die of colorectal cancer, representing approximately 10

percent of all cancer deaths (Cancer Facts and Figures 2007). If you

prevented 72 percent of these deaths you would save 37,570 lives each

year. To comprehend this graphically, the seating capacity of Fenway

Park in Boston is 38,805. Thus, you could nearly fill this stadium to

capacity with the people whose deaths from colorectal cancer could be

avoided each and every year. Worldwide, the United Nations estimates

that there are 500,000 deaths from colorectal cancer each year (W.H.O.

World Cancer Report 2003). A 72 percent reduction would mean 360,000

lives saved each year. That's a lot of lives saved and a lot of misery

avoided!

There is some disagreement over how much vitamin D is necessary in order

to raise the blood level to 80 nmol/L. As a general rule, the government

advocates the intake of 400 IU vitamin D per day. But some Canadian

experts feel that a minimum of 800 IU/day to 1000 IU/day may be needed,

with up to 2000 IU/day to 4000 IU/day in special circumstances (Canadian

Pediatric Society 2007).

One hundred tablets of 800 IU of vitamin D can be purchased on the

Internet for under $2.00 ($1.94). Thus, most people could supply

themselves with sufficient amounts of supplemental vitamin D for 2¢ per

day, or around $7.50 per year. By comparison, Leonard Saltz, M.D., an

expert on colon cancer treatment at Memorial Sloan-Kettering Cancer

Center, N.Y., has estimated that the cost of chemotherapy for advanced

colon cancer is approximately $250,000. Thus the cost of treating just

one case of colon cancer would be enough to prevent death from colon

cancer in over 30,000 cases. This is a perspective that somehow failed

to come across in the vast majority of recent media stories about

vitamin D and cancer.

--Ralph W. Moss, Ph.D.

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References:

Canadian Pediatric Society: Vitamin D supplementation: Recommendations

for Canadian mothers and infants. Accessed at:

http://www.cps.ca/english/statements/II/FNIM07-01.htm

Cost of cancer treatment:

http://www.usatoday.com/news/health/2006-07-10-cancer-costs_x.htm

Freedman DM, Looker AC, Chang SC, et al. Prospective study of serum

vitamin D and cancer mortality in the United States. J Natl Cancer Inst

2007 Nov 7;99(21):1594-602.

W.H.O. World Cancer Report:

http://www.who.int/mediacentre/news/releases/2003/pr27/en/

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