Colon Cancer 30 percent higher risk if low vitamin D (optimally need ~40 ng) – Feb 2019

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Circulating Vitamin D and Colorectal Cancer Risk: An International Pooling Project of 17 Cohorts — Feb 2019

JNCI: Journal of the National Cancer Institute, Vol 111, Issue 2, 1 Feb 2019, Pages 158–169, https://doi.org/10.1093/jnci/djy087
Marjorie L McCullough Emilie S Zoltick Stephanie J Weinstein Veronika Fedirko Molin Wang Nancy R Cook A Heather Eliassen Anne Zeleniuch-Jacquotte Claudia Agnoli Demetrius Albanes ...

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Background
Experimental and epidemiological studies suggest a protective role for vitamin D in colorectal carcinogenesis, but evidence is inconclusive. Circulating 25-hydroxyvitamin D (25(OH)D) concentrations that minimize risk are unknown. Current Institute of Medicine (IOM) vitamin D guidance is based solely on bone health.

Methods
We pooled participant-level data from 17 cohorts, comprising 5706 colorectal cancer case participants and 7107 control participants with a wide range of circulating 25(OH)D concentrations. For 30.1% of participants, 25(OH)D was newly measured. Previously measured 25(OH)D was calibrated to the same assay to permit estimating risk by absolute concentrations. Study-specific relative risks (RRs) for prediagnostic season-standardized 25(OH)D concentrations were calculated using conditional logistic regression and pooled using random effects models.

Results
Compared with the lower range of sufficiency for bone health (50–<62.5 nmol/L), deficient 25(OH)D (<30 nmol/L) was associated with 31% higher colorectal cancer risk (RR = 1.31, 95% confidence interval CI = 1.05 to 1.62); 25(OH)D above sufficiency (75–<87.5 and 87.5–<100 nmol/L) was associated with 19% (RR = 0.81, 95% CI = 0.67 to 0.99) and 27% (RR = 0.73, 95% CI = 0.59 to 0.91) lower risk, respectively. At 25(OH)D of 100 nmol/L or greater, risk did not continue to decline and was not statistically significantly reduced (RR = 0.91, 95% CI = 0.67 to 1.24, 3.5% of control participants). Associations were minimally affected when adjusting for body mass index, physical activity, or other risk factors.
For each 25 nmol/L increment in circulating 25(OH)D, colorectal cancer risk was

• 19% lower in women (RR = 0.81, 95% CI = 0.75 to 0.87) and
• 7% lower in men (RR = 0.93, 95% CI = 0.86 to 1.00)

(two-sided Pheterogeneity by sex = .008). Associations were inverse in all subgroups, including colorectal subsite, geographic region, and season of blood collection.

Conclusions
Higher circulating 25(OH)D was related to a statistically significant, substantially lower colorectal cancer risk in women and non–statistically significant lower risk in men. Optimal 25(OH)D concentrations for colorectal cancer risk reduction, 75-100 nmol/L, appear higher than current IOM recommendations.

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2X more likely to survive if >20 ng of vitamin D after CC surgery - April 2019

Higher Post-Operative Serum Vitamin D Level is Associated with Better Survival Outcome in Colorectal Cancer Patients.
Nutr Cancer. 2019 Apr 4:1-8. doi: 10.1080/01635581.2019.1597135.
Markotic A1,2, Langer S3, Kelava T2,4, Vucic K5, Turcic P6, Tokic T7, Stefancic L8, Radetic E7, Farrington S9, Timofeeva M9, Rudan I10, Campbell H10, Dunlop M9, Kirac I11, Zgaga L12.

25-Hydroxyvitamin D (25-OHD) may have a prognostic value in colorectal cancer (CRC) patients. However, as 25-OHD concentration is strongly impacted by surgery, it is uncertain what is the most reliable time-point for 25-OHD assessment, pre- or post-operative. Therefore, we examined 515 CRC patients (AJCC I-III) who underwent surgery. Blood samples were collected either pre-operatively (n = 286; median = 1 day before surgery) or post-operatively (n = 229; median = 8 days). Serum 25-OHD concentration was determined by liquid chromatography-tandem mass spectrometry. Association between 25-OHD and survival was tested in the whole cohort, followed by stratified analyses in pre- and post-operatively sampled. Median 25-OHD in the cohort was 36.7 nmol/L and median follow-up time was 5.9 years. There were no differences between pre- and post-operative cohort in age, sex, 25-OHD, AJCC stage, or localization of tumor.
After adjustment, higher 25-OHD (>50 nmol/L) was associated with better overall survival only in post-operative (HR = 0.53; 95% CI: 0.33-0.84; P = 0.006), but not in pre-operative cohort (HR = 1.13; 95% CI: 0.77-1.65; P = 0.53). In conclusion, higher post-operative 25-OHD levels were associated with better survival outcome in CRC patients, while no such association was found for pre-operative levels. Time-point of blood collection should be addressed carefully in future research as it might affect the prognostic value of 25-OHD in CRC.