Circulating Vitamin D Levels and Risk of Colorectal Cancer in Women

Abstract

Observational data on the association between circulating 25(OH)D and colorectal cancer risk are limited in women. To determine whether prediagnostic levels of 25(OH)D were associated with risk of incident colorectal cancer in the Women’s Health Study (WHS), we conducted a nested case-control study using 274 colorectal cases and 274 controls. Each case was matched to a control by age, ethnicity, fasting status at the time of blood collection, time of day when blood was drawn, and month of blood draw. Conditional logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI) for colorectal cancer by 25(OH)D quartiles. Mean plasma 25(OH)D was lower in cases versus controls (21.9 vs 23.9 ng/mL, p=0.01). In multivariable-adjusted logistic regression models, plasma 25(OH)D was significantly and inversely associated with odds of colorectal cancer (quartile 4 [Q4] versus quartile 1 [Q1]: OR (95% CI): 0.45 (0.25–0.81), ptrend 0.02). Additionally, we observed a somewhat lower risk of colorectal cancer mortality after adjustment for matching variables, randomization treatment and other risk factors (Q4:Q1 OR[95%CI]: 0.40(0.17–0.97); ptrend 0.05). In this cohort of healthy women, we found a significant inverse association between prediagnostic 25(OH)D levels and risk of incident colorectal cancer, and a borderline significant inverse association between prediagnostic 25(OH)D levels and colorectal cancer mortality. These results support a possible association between plasma 25(OH)D and risk of colorectal cancer in women.

Total and Free Circulating Vitamin D and Vitamin D–Binding Protein in Relation to Colorectal Cancer Risk in a Prospective Study of African Americans

“…A 2011 meta-analysis of prospective epidemiologic studies computed an OR for colorectal cancer of 0.66 for participants in the highest versus lowest quartile of 25-hydroxyvitamin D levels (2). More recent publications that described data from the Women’s Health Initiative and the Prostate, Lung, Colorectal and Ovarian Cancer Screening trials also report 25-hydroxyvitamin D to be inversely association with colorectal cancer risk (9,26). Similar to these previous epidemiologic studies, we observe a decreased risk for participants in the highest versus lowest tertile of total 25-hydroxyvitamin D, and a consistent inverse association when total 25-hydroxyvitamin D is modeled in per standard deviation increments.…”

Vitamin D and Cancer Risk and Mortality: State of the Science, Gaps, and Challenges

“…Inverse associations of similar magnitudes were shown by Touvier et al (10) for colon and rectal cancer per 100-IU/L increase in circulating 25(OH)D, whereas Gandini et al (7) reported a similar inverse association for colorectal cancer per 25-nmol/L increase in circulating 25(OH)D but did not examine colon and rectal cancer separately. Two subsequent individual studies also found inverse colorectal cancer associations (11,12), and 1 other study suggested an increased risk with a higher level of vitamin D for colon cancer (13).…”

Making Sense of Vitamin D Concentrations

“…The most discussed articles are those investigating the link between vitamin D status and diseases such as dementia [1,2] or cancer [3,4], although articles about the influence of vitamin D on infections, asthma, anorexia, cardiovascular diseases, diabetes, and more than a hundred other outcomes [5] are just as common. The main recognized function of vitamin D is to maintain appropriate levels of calcium and phosphate for bone mineralization, muscle contraction, nerve conduction and general cellular function [6].…”