While vitamin D has been implicated in colorectal cancer (CRC) pathogenesis, to determine the association between vitamin D intake and risks of early-onset CRC and precursors among women enrolled in Nurses’ Health Study II, the association was examined.
Multivariable-adjusted hazard ratios (HRs) for early-onset CRC were estimated with Cox proportional hazards model. Multivariableadjusted odds ratios (ORs) for early-onset conventional adenomas and serrated polyps were estimated with logistic region model.
A total of 111 incident cases of early-onset CRC were documented during 1,250,560 person-years of followup (1991 to 2015). Higher total vitamin D intake was significantly associated with a reduced risk of early-onset
CRC (HR >450 IU/day vs <300 IU/day, 0.49; HR per 400 IU/day increase was 0.46). The inverse association was significant and appeared more evident for dietary sources of vitamin D than supplemental vitamin D (HR per 400 IU/day increase 0.77). For CRC precursors, ORs per 400 IU/day increase were 0.76 for conventional adenoma and 0.85 for serrated polyp.
It was concluded that in a cohort of younger women, higher total vitamin D intake was associated with decreased risks of early-onset CRC and precursors.
Kim, H., Lipsyc-Sharf, M., Zong, X., et al. “Total Vitamin D Intake and Risks of Early-Onset Colorectal Cancer and Precursors.” Gastroenterology 2021; Vol. 161, pp. 1208-1217, October 2021.