Page 308 - Vitamin D and Cancer

Chapter 13
Vitamin D and Colorectal Cancer

Marwan Fakih, Annette Sunga, and Josephia Muindi

Abstract An inverse association between sunlight exposure and colon cancer
mortality has been previously described. This protective effect has been attributed
to increased vitamin D synthesis. Indeed, vitamin D deficiency has been repeatedly
associated with an increased risk of adenomatous polyp recurrence and increased
colorectal cancer incidence in case–control studies, supporting a direct role for this
vitamin against colorectal carcinogenesis. Despite the supporting epidemiological
evidence, the Women Health Initiative (WHI) prevention trial failed to demonstrate
any reduction in colorectal cancer with 400 IU/day of vitamin D.
We show that dosing at or in excess of 2,000 IU/day of vitamin D3 may be
required to achieve optimal serum levels. Prospective studies of such doses need to
be investigated to adequately test vitamin D in colorectal cancer prevention. We
also review the status of vitamin D in patients with metastatic disease where we
demonstrate severe insufficiency and decreased response to vitamin D supplemen-
tation, supporting the need of a more aggressive approach in this population.

Keywords Vitamin D • Colorectal cancer • Polyps • Prevention • Chemotherapy

13.1 Epidemiology of Vitamin D and Colorectal Cancer

13.1.1 Sunlight and Colorectal Cancer

An inverse association between sunlight exposure and the risk of certain cancers has
long been recognized. One of the first reports to indirectly suggest the association
between sunlight and a decreased incidence of non-skin cancer was in 1936 when
Peller reported an inverse association between a higher incidence of skin cancer and

M. Fakih (*)
Roswell Park Cancer Institute, Elm & Carlton Streets, Buffalo, NY 14263, USA
e-mail: marwan.fakih@roswellpark.org

D.L. Trump and C.S. Johnson (eds.), Vitamin D and Cancer, 295
DOI 10.1007/978-1-4419-7188-3_13, © Springer Science+Business Media, LLC 2011