Higher vitamin D intake may reduce risk of colorectal cancer: Study

The role of Vitamin D has been greatly discussed in colorectal cancer (CRC) pathogenesis; however, it is unclear whether the total vitamin D intake is linked with early-onset colorectal cancer.

A study was conducted by a group of researchers from Harvard T.H. Chan School of Public Health, U.S.A, to investigate the association of increased dietary intake of total Vitamin D and its association with early-onset colorectal cancer and precursors diagnosed before age 50.

The researchers studied the potential linkage between total vitamin D intake and risks of early-onset colorectal cancer and precursors among a cohort of young women recruited in the Nurses' Health Study II.

In total, they recorded 111 incident cases of early-onset colorectal cancer during 1,250,560 person-years of follow-up (1991 to 2015).

They predicted the multivariable-adjusted hazard ratio (HR) and 95% confidence interval (CI) for early-onset colorectal cancer by using the Cox proportional hazards model.

Further, Multivariable-adjusted odds ratio (OR) and 95% CI for early-onset conventional adenoma and serrated polyp were predicted using a logistic regression model.

The results of the study are as follows:

· Higher total vitamin D intake was significantly associated with a reduced risk of early-onset colorectal cancer.

· While the inverse association was prominent, it appeared more evident for dietary sources of vitamin D.

· In case of colorectal cancer precursors, the Odds ratio per 400 IU/day increase were 0.76 (95% CI, 0.65-0.88) for conventional adenoma (n = 1,439) and 0.85 (95% CI, 0.75-0.97) for serrated polyp (n = 1,878).

The researchers concluded that higher total vitamin D intake was actually associated with decreased risks of early-onset CRC and precursors.

Reference:

A study titled, "Total vitamin D intake and risks of early-onset colorectal cancer and precursors" by Kim H published in Gastroenterology.

DOI: https://doi.org/10.1053/j.gastro.2021.07.002