1. ROLE OF VITAMIN D
IN
PREVENTION OF CANCER
PRESENTED BY:
MR. ASHWIN THOMAS, MSN
HIND COLLEGE OF NURSING,
LUCKNOW, U.P.

2. INTRODUCTION:
Among the diseases of modern times,
the term cancer has encircled the health
sectors nowadays. Because of the limited
treatment modalities available in medicine
today, the emphasis is shifting on finding a
way or ways to prevent cancers.
In that relation, recent research results
and studies are pointing towards vitamin D
as the possible aid in preventing
malignancy.

3. OVERVIEW OF VITAMIN D:
Vitamin D is a group of fat-soluble
prohormones the two major forms of which
are vitamin D2 (or ergocalciferol) and
vitamin D3 (or cholecalciferol). The term
vitamin D also refers to metabolites and
other analogues of these substances.
Vitamin D3 is produced in skin exposed to
sunlight, specifically ultraviolet B radiation.

4. FUNCTIONS OF VITAMIN D:
Maintenance of organ systems.
Vitamin D regulates the calcium and phosphorus
levels in the blood by promoting their absorption from
food in the intestines, and by promoting re-
absorption of calcium in the kidneys. It is also
needed for bone growth and bone remodeling by
osteoblasts and osteoclasts.
In the absence of vitamin K Vitamin D can promote
soft tissue calcification.
It inhibits parathyroid hormone secretion from the
parathyroid gland.
Vitamin D affects the immune system by promoting
phagocytosis, and immunomodulatory functions.

5. VITAMIN D IN CANCER PREVENTION AND
RECOVERY:
The vitamin D hormone, calcitriol, has
been found to induce death of cancer cells.
Although the anti-cancer activity of vitamin D
is not fully understood, it is thought that these
effects are mediated through vitamin D
receptors expressed in cancer cells, and may
be related to its immunomodulatory abilities.
The anti-cancer activity of vitamin D
observed in the laboratory has prompted
some to propose that vitamin D
supplementation might be beneficial in the
treatment or prevention of some types of
cancer.

6. Vitamin D regulates the expression of genes
associated with cancers and autoimmune
disease by controlling the activation of the
vitamin D receptor (VDR), a type 1 nuclear
receptor and DNA transcription factor. Research
has indicated that vitamin D deficiency is linked
to colon cancer and more recently, to breast
cancer.
The Canadian Cancer Society recommends that
adults should consider supplementing with 1,000
IU of vitamin D per day during the fall and winter.
They base this recommendation on the growing
evidence for a link between vitamin D and a
reduced risk for colorectal, breast and prostate
cancers.

7. Cancer prevention specialists have
concluded that taking 1,000 international
units (IU) of vitamin D3 per day may lower
an individual’s risk of developing certain
cancers, including breast, colon, prostate,
and ovarian, by up to 50 percent.

8. In 2007, scientists released a study which
demonstrated a beneficial correlation
between vitamin D intake and prevention of
cancer. Drawing from a meta analysis of 63
published reports, the authors showed that
intake of an additional 1,000 international
units (IU) (or 25 micrograms) of vitamin D
daily reduced an individual's colon cancer
risk by 50%, and breast and ovarian cancer
risks by 30%. Research has also shown
a beneficial effect of high levels of calcitriol
on patients with advanced prostate cancer.

9. A randomized intervention study involving 1,200
women, published in June 2007, reports that
vitamin D supplementation (1,100 international
units (IU)/day) resulted in a 60% reduction in
cancer incidence, during a four-year clinical trial,
rising to a 77% reduction for cancers diagnosed
after the first year (and therefore excluding those
cancers more likely to have originated prior to
the vitamin D intervention).
In 2006, a study at Northwest University found
that taking the U.S. RDA of vitamin D (400 IU
per day) cut the risk of pancreatic cancer by
43% in a sample of more than 120,000 people
from two long-term health surveys.

10. A 2008 study using data on over 4 million
cancer patients from 13 different countries
showed a marked difference in cancer risk
between countries classified as sunny and
countries classified as less–sunny for a
number of different cancers. Research has
also suggested that cancer patients who
have surgery or treatment in the summer
therefore make more endogenous vitamin D
and have a better chance of surviving their
cancer than those who undergo treatment in
the winter when they are exposed to less
sunlight.

11. The breast cancer study, published online in the
current issue of the Journal of Steroid
Biochemistry and Molecular Biology, pooled
dose-response data and found that individuals
with the highest blood levels of 25-
hydroxyvitamin D, or 25(OH)D, had the lowest
risk of breast cancer.
New research published this month shows that
vitamin D supplementation produces an
astonishing 77 percent reduction in all cancers
in women, making it the single most effective
medicine for preventing cancer that has ever
been discovered by modern medical science.

12. Recently, research led by Kimmie Ng,
M.D., M.P.H., of the Dana-Farber Cancer
Institute has revealed that vitamin D can
improve the survival rates of people with
colorectal cancer. The findings of this study
are very significant because, in a way, they
break new ground. While previous research
had largely centered on how vitamin D levels
reduce colorectal cancer incidence, this
study has established a connection between
vitamin D levels and the survival chances of
people who have already gotten the disease.

13. FUTURE DIMENSIONS OF
DISCOVERY:
Although the cohort findings are likely to
increase enthusiasm for the cancer
prevention potential of vitamin D, inherent
limitations of observational epidemiologic
studies combined with a history of prior
disappointments with other potential chemo
preventive agents suggest caution in their
interpretation.

14. Two decades ago there was intense interest
and hope that supplementation with beta-
carotene might reduce the risk of several
cancers. Epidemiologic studies have
consistently reported that men and women with
the highest dietary intakes of beta-carotene as
well as with elevated blood levels experienced
lower risks of respiratory, gastrointestinal, and
other cancers. The zeal was crushed, however,
when randomized trials in the United States and
Finland showed increased rather than
decreased risks of lung cancer among adults
receiving beta-carotene supplements.

15. Vitamin E was similarly touted as an
inhibitor of cancer, as well as of
cardiovascular disease, but again the "gold
standard" of randomized trials failed to
confirm the preventive correlations noted in
cohort and case–control studies.

16. In each of these examples, the agents
may have demonstrated benefit with
modification of the dose, formulation, or
timing of the intervention or with longer
follow-up, but the sobering lesson is that
trends observed in non experimental
settings, including cohort studies, are not
always confirmed experimentally when
tested in randomized clinical trials.

17. Science, after all, is a continual process of
hypothesis formulation, testing, and
refinement.
Ecologic (e.g., geographic correlations)
and analytic (e.g., cohort and case–control)
studies provide the evidence-based clues to
cancer etiology, but randomized trials are
generally needed to confirm these leads and
develop effective disease prevention
strategies.

18. CONCLUSIONS:
The role of vitamin D in cancer prevention
is strongly suggested by epidemiologic
observations and potential mechanisms have
been identified by experimental studies. The
promising results from both observational and
laboratory studies should usher in a new era
of intervention studies of vitamin D and cancer
risk. Because many public health scientists
are already clamoring for higher levels of
vitamin D supplementation for bone and other
health, randomized trials of vitamin D and
cancer risk should be undertaken speedily.

19. If the promise of vitamin D holds,
a brief walk in the sun may turn
out to be a step toward cancer
prevention.

20. BIBLIOGRAPHY:
 Garland CF, Garland FC. (2007). Do sunlight and
vitamin D reduce the likelihood of colon
cancer? International Journal of
Epidemiology; 9:227–31.
 Giovannucci E, Liu Y, Rimm EB, Hollis BW, Fuchs
CS, Stampfer MJ, Willett WC.(2008).
Prospective study of predictors of vitamin D
status and cancer incidence and mortality in
men. Journal of National Cancer Institute;
98:451–9.
 Gorham ED, Lipkin M, Newmark H, Mohr SB, et al.
(2008) The role of vitamin D in cancer
prevention. American Journal of Public
Health;96:252–61.

21.  Holick M F. (2007). Vitamin D. A millennium
perspective. Journal of Cellular
Biochemistry. 88:296–307.
 Wactawski-Wende J, Kotchen JM, et al.(
2008).Calcium plus vitamin D
supplementation and the risk of colorectal
cancer. New England Journal of
Medicine;354:684–96
 Gary Schwartz, and William B, (2008). Vitamin
D status and cancer incidence and mortality:
something new under the sun. Journal of the
National cancer Institute, 98:7,428-30.