Page 313 - Vitamin D and Cancer

300 M. Fakih et al.

Fig. 13.3 Cholecalciferol 8
dose effect and time course 2000IU
of changes in serum 24,
25-D levels in colorectal 6 400IU
3
cancer patients. Serum 24,25-
D levels determined by
3
atmospheric pressure chemi- Serum 24,25-D 3 (ng/mL) 4
cal ionization (APCI) in posi-
tive ion mode LC/MS/MS.
Data = mean + SEM 2

0
0 2 4 6 8 10
Time (months)

and time course of the changes in serum 24, 25-D in this cohort of colorectal can-
3
cer patients is shown in Fig. 13.3. These results suggest that comprehensive profiles
of serum vitamin D metabolite in cancer patients are now achievable.
3

13.1.2.3 Vitamin D Status and Adenomatous Polyps

Several studies suggest a correlation between vitamin D intake or 25-hydroxy vita-
min D (25-D ) status and the risk of adenomatous polyps (Table 13.1). Levine et al.
3
conducted a case–control study where 473 patients with a finding of at least one
adenoma on initial sigmoidoscopy were compared to controls without any polyps
on sigmoidoscopy or without any prior history of adenoma [33]. Plasma 25-D was
3
assayed by a competitive binding assay. Increasing plasma levels of 25-D was
3
associated with a decreased risk of adenoma (OR = 0.74 for the highest quartile
compared to lowest; CI 0.49–1.09). The benefit from higher serum 25-D was more
3
pronounced in the population with lower calcium intake. In another case–control
study, 222 patients with newly diagnosed adenomas on colonoscopy were com-
pared to 479 controls who had adenoma-free colonoscopies [34]. One hundred and
eleven cases and 238 controls had available serum for 25-D assay by enzyme
3
immunoassay. A significant association was present between the highest tertile of
25-D and a lower risk of adenoma in comparison to the lowest tertile (OR 0.51; CI
3
0.27–0.98). Contrary to the findings by Levine, the benefit noted on this study
seemed more pronounced in the population with a higher calcium intake. In the
third study, 239 patients with colonic adenomas diagnosed by sigmoidoscopy were
compared to 228 controls with an adenoma-free sigmoidoscopy [35]. 25-D ,
3
assayed by RIA, was found protective against adenoma formation, with a risk
reduction by 26% for each 10 ng/mL increase in serum levels. Only one study
failed to show a clear association between 25-D and polyps [36]. In this study,
3
cases and controls were drawn from the Nurse’s Health Study. Cases were
diagnosed to have at least one adenoma by endoscopy and were compared with