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Supplements and Colorectal Cancer Risk -- colon cancer diagnosis form and supplements


There is good evidence that getting adequate folate and fiber from foods and supplements can reduce the risk of developing colorectal cancer. (Listen to's Fiber Supplements Webinar for more on fiber and colon health).

In people with low blood levels of selenium, selenium supplements have been found to reduce the risk of colon cancer, and in people who smoke, taking curcumin can reduce early changes in the colon that can lead to cancer.

Maintaining higher levels of vitamin D in the body -- which can be achieved through exposure to sunlight or obtained from foods and supplements -- is associated with a reduced risk of developing colorectal cancer.

Although preliminary research had suggested that calcium supplements might reduce the risk of colon polyps or colon cancer, large clinical trials failed to show a benefit with high doses.  

Intake of omega-3 fatty acids EPA and DHA from fish and/or fish oil supplements is associated with a lower risk of death from colorectal cancer. However, it may interfere with chemotherapy.

Observational studies have also found an association between higher olive oil intake and a reduced risk of colorectal cancer.

Green tea extract has been shown to reduce the recurrence of polyps, which can sometimes turn into colon cancer.

Observational studies suggest that regular yogurt consumption is associated with a reduced risk of colorectal polyps and colorectal cancer, particularly in men.

Although a high dietary intake of CLA (conjugated linoleic acid) from high-fat dairy foods has been associated with a reduction of colorectal cancer by up to 39% in women, it is not known if taking CLA supplements has this potential benefit.

For more information about each of these supplements, use the links above.

Interestingly, regular use of aspirin may either reduce or increase the risk of colorectal cancer depending on the age at which aspirin use is initiated. For details, sign in as a ConsumerLab member.

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March 11, 2015

Don't forget coffee either.

March 11, 2015

You left out aspirin. Daily aspirin reduces colon cancer risk by 40%, at least in epidemiological studies (I'd put the link in here but it's not allowed. Just google "Daily Aspirin May Help Prevent Cancer, Study Shows").

If aspirin doesn't qualify as a supplement for some reason, there are willow bark extracts containing salicin which is virtually the same molecule and works by the same mechanism.

September 3, 2015

I am a colon cancer recovered person and cancer free for five years. I avoided chemo / radio therapy for my stage III cancer. I am regularly taking only food supplements for the past five years after my colorectomy surgery. My regular supplements are: curcumin, Ginger, omega 3, (Budwigs diet), D3, selenium, coQ10, spanish saffron, green tea extract (stopped for the past one year) apart from regular intake of fruits like pomegranate, papaya, greens like, broccoli, other cruciferaces, I am normal at the age of 65. hope my experience may help to other cancer patients.
Dr.S.Paulraj, Ph.D.

November 10, 2015

Thanks for sharing, SUBBIAH6915. I also think chemo really hurts our body. Of course sometimes we still need the surgery to save our lives. But the most important thing is how to stimulate our immune system. I'd rather some natural therapies (such as Gerson therapy) than chemo.

By the way, could you let me know how many doses of curcumins do you take daily?

I usually take high doses of Vit C (8-10g), Mg (800mg), D3 (4000-7000IU), K2 (60-150mcg), B-complex, and probiotics daily. I'm going to try curcumins and hope it will benefit my health too.

Ps. If I take D3 7000IU, then K2 would be 150mcg. If D3 4000IU-5000IU, than K2 would be 60-75mcg.
November 10, 2015

Dear A.8039 - Under normal circumstances, the amounts of vitamins you indicate taking could do more harm than good. Those doses (aside from that for vitamin K) are all far above the recommended intakes as well as above the tolerable upper intake levels from supplements, above which there is increasing risk of toxicity.

You may want to review the information in our reports on Vitamin C ( Magnesium ( and Vitamin D (

For example, while blood plasma levels of vitamin D in the middle 30s (ng/mL) have been associated with reduced risk of gastrointestinal cancers compared to lower levels, the amount you are taking could boost levels far beyond that (into the 40s, 50s, or 60s) to where there is increased risk of mortality -- not a good trade-off. It would be interesting to know the rationale behind the regimen you outlined, if you wish to share.

November 10, 2015


I take 1g of Vit C per hour. The biological half-life of vitamin C is about 30 mins.

I have a Vit D deficiency, some feminine health and immune system issues, so that all consumption of vitamins within my body would be larger than health people. (Some doctors even would let their patients take Vit C by injection to relieve their cancer pain. The dosage is usually 30-50g or higher. And it is legal.)

If someone need to take high doses of Vit C, then he/she needs Mg to balance blood sugar levels (Mg plus Ca is also ok but Mg is more important.)

Please note:
When women have feminine health issues like endometriosis, that means they have estrogen dominance. Mg levels fluctuate during a woman's cycle. The higher the estrogen, the lower the Mg. Also, Vit D needs Mg (and Vit K) to work together.

The dosage of RDA is for health people not for someone who is suffering illness especially cancer. That's why we need to take so high doses of vitamins.

Actually I really feel better after taking these doses. And my ovarian cysts, uterine fibroids, and lymph nodes behind ear are getting smaller and smaller. I did not get colds from starting to take these doses of supplements. (I did not take any medicine anymore during these years, except of these supplements.)

March 6, 2016

Thank you for sharing that.

March 6, 2016

Get the book AntiCancer by dr david schreiber, great tips

March 28, 2016

Thank you for sharing this valuable info.

March 12, 2017

I used to take cofq10 and selenium until I came across research that indicated that it could be counterproductive. I am not taking dairy and so stopped Budwigs diet. I am taking vitamin d3, k2, curcumin, alpha lipoic acid, bromelain, ldn( low dose Natroxene),dairy free diet, sugar free diet, low carbohydrate diet, wheat free diet, mushroom extract supplement, vitamin B complex, vitamin C, salvestol, probiotics (progreens), ashwangdha, Amla, Boswellia Extract, low dose aspirin, simvastatin, low dose metformin, tagamet. avemar, i am not sure what works but i have had colon cancer followed by liver tumors but have been cancer free for three years.

March 16, 2017

Some people have personal experiences and beliefs, but discussing megadoses is not a good guide for most people. ConsumerLab might consider removing such posts.

February 25, 2018

Tell that to Linus Pauling, nobel award winner who rec. megadoses of vit c for healing.
February 26, 2018

Hi Foster - Even experts at the Linus Pauling Institute acknowledge that intake of about 400 mg of vitamin C should be sufficient to saturate your blood plasma and circulating cells with vitamin C ( High doses of vitamin C can cause short-term and long-term problems. Please see this CL Answer for more about that:
February 26, 2018

As noted in our response directly above your comment, high doses of vitamin C, vitamin D, calcium and magnesium can be harmful. Please see the "Concerns and Cautions" sections in the Vitamin C Review (, the Calcium Supplements Review (, and the Magnesium Supplements Review ( as well as the "How much is too much?" section of the Vitamin D Supplements Review (

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