Studies about vitamin D and colon cancer:
Is Prevention of Cancer by Sun Exposure More Than Just the Effect of Vitamin D? A Systematic Review of Epidemiological Studies (2013)
Conclusion: “We found that almost all epidemiological studies suggest that chronic (not intermittent) sun exposure is associated with a reduced risk of colorectal-, breast-, prostate cancer and NHL.”
Conclusion: In a four-year population-based, double-blind, randomized placebo-controlled trial involving 1179 postmenopausal Nebraska women, women receiving a daily dose of 1500mg/day of supplemental calcium and 1100 IU/day of Vitamin D had a 77% lower risk for all types of cancer compared to the placebo group.
Conclusion: 304 female participants from the Nurses Health Study who were diagnosed with colorectal cancer between 1991 and 2002 were observed until 2005 or until they died. Those with higher vitamin D levels around the time of diagnoses had higher survival rates.
Conclusion: People with vitamin D levels above 33 ng/ml have a 50% lower risk of developing colorectal cancer than people with levels below 12 ng/ml.
Conclusion: Decade-long longitudinal study of 16,818 subjects found that those with vitamin D levels above 32 ng/ml had a 72% lower risk for colorectal cancer.
A Nested Case Control Study of Plasma 25-Hydroxyvitamin D Concentrations and Risk of Colorectal Cancer (2007)
Conclusion: 179 participants in long-term (8-11 year) longitudinal studies developed colon cancer. Their initial vitamin D levels at the beginning of the study were compared to 356 matched, cancer-free controls. Researchers found that the participants who later developed colon cancer had lower vitamin D levels when the study first began years prior.
Estimation of Optimal Serum Concentrations of 25-Hydroxyvitamin D For Multiple Health Outcomes (2006)
Conclusion: People with lower vitamin D levels have a higher risk of developing colorectal cancer
Conclusion: Sun exposure and vitamin D prevent colon, breast, prostate, and ovarian cancer.
Conclusion: A meta-analysis of 18 scientific studies on the relationship between vitamin D supplementation, serum vitamin D levels, and colon cancer survival found that those who consume at least 1,000 IU of vitamin D daily or have adequate vitamin D levels have a 50% lower risk for developing colon cancer.
1alpha,25-Dihydroxyvitamin D3 Regulates the Expression of Id1 and Id2 Genes and the Angiogenic Phenotype of Human Colon Carcinoma Cells (2005)
Conclusion: “1alpha,25-Dihydroxyvitamin D3 (1alpha,25(OH)2D3) [vitamin D] has antitumor activity in addition to its classical action on calcium metabolism and bone tissue biology.”
Conclusion: Colon cancer cells were injected into vitamin D-deficient mice and vitamin D-sufficient mice. 20 days later, all mice had tumors, but the tumors of the mice with higher vitamin D levels were 40% smaller than the deficient mice. “We conclude that vitamin D deficiency enhances the growth of colon cancer in mice.”
Conclusion: Within the U.S., the states with the highest amount of solar radiation (New Mexico, Arizona, Florida, California, Texas – low latitudes) have the lowest rates of colon cancer mortality and the states with the lowest solar radiation (New York, New Jersey, Rhode Island, Connecticut – high latitudes) have the highest rates of colon cancer mortality. Lower latitude populations tend to have higher vitamin D levels than higher latitude populations.
Conclusion: Older women with lower vitamin D levels have a higher colorectal cancer risk
Phytoestrogens and Vitamin D Metabolism: A New Concept for the Prevention and Therapy of Colorectal, Prostate, and Mammary Carcinomas. (2004)
Conclusion: Optimization of vitamin D levels is important for tumor prevention
Conclusion: 115,096 cases of breast, colon, and prostate cancer diagnosed over a 28-year period were observed. Researchers found that patients diagnosed in the summer and fall, when population vitamin D levels are highest, had the lowest cancer fatality rate. “The results suggest that a high level of vitamin D3 at the time of diagnosis, and thus, during cancer treatment, may improve prognosis of the three cancer types studied.” The study also found that men and women who received medium to high levels of occupational sun exposure had an extraordinarily lower cancer fatality rate compared to people with low occupational sun exposure.
Sunlight and Mortality From Breast, Ovarian, Colon, Prostate, and Non-Melanoma Skin Cancer: A Composite Death Certificate Based Case-Control Study (2002)
Conclusion: Sun exposure lowers your risk of developing breast, ovarian, prostate, and colon cancer
An Estimate of Premature Cancer Mortality in the U.S. Due to Inadequate Doses of Solar Ultraviolet-B Radiation (2002)
Conclusion: Lack of midday sun exposure increases one’s risk for developing and dying from breast, colon, ovarian, prostate, bladder, esophageal, kidney, lung, pancreatic, rectal, stomach, and uterine cancer.
Conclusion: Regions of America that have higher rates of rickets/osteomalacia have also been found to have higher rates of colon cancer. Rickets is a well-documented severe symptom of vitamin D-deficiency.
Conclusion: Optimizing your vitamin D levels drastically reduces your risk of developing colon cancer.