These common, doctor-recommended supplements linked to colon cancer

I regularly urge you to get your calcium from food sources, since research links calcium supplements to a bevy of health problems (most notably, hardening of the arteries).

And now, according to a new study conducted by researchers at the University of North Carolina School of Medicine in Chapel Hill, there’s another reason to avoid calcium supplementation…

Increased colon cancer risk.

It’s ironic, really. Mainstream doctors generally believe that all the needed, safe, and effective nutritional supplements are dangerous. Or — at best — useless.

But they have no problem recommending calcium supplements — which actually do cause harm. (They also regularly promote iron, which is one of the very few other supplements that is truly harmful.)

I suppose this ignorance stems from earlier research that suggested people with higher dietary intake of calcium ran a lower risk of developing colon polyps, including the precancerous types.

But, as I often remind you, there is a world of difference between getting your calcium from foods in your diet versus artificial calcium supplements. And for 25 years, in my medical textbook, Fundamentals of Complementary and Alternative Medicine, and elsewhere, I’ve warned against embarking on multi-million dollar studies of dietary supplements without first knowing and understanding the fundamentals science of diet, nutrition, and dietary supplementation.

The researchers in the new study were so ignorant of the fundamental sciences, they initially thought the calcium supplementation might reduce the risk of precancerous polyps in the colon. And they designed this study to test their hypothesis.

Calcium supplements tied to more than double the risk of precancerous polyps

The new study involved 2,259 participants, ages 45 to 75 years old, from 11 U.S. academic medical centers. All the participants had a history of polyps.

To start, the researchers randomly divided the participants into four groups. The first groups took 1,200 mg per day of calcium for three to five years. The second group took 1,000 IU per day of vitamin D. The third group took both calcium and vitamin D. And the fourth group took a placebo.

During the initial treatment phase of three to five years, the researchers observed no significant differences among the groups.

But six to 10 years after stopping supplementation, the participants who had received calcium supplements or calcium plus vitamin D supplements had a 2.7-times increased risk of developing precancerous polyps.

The analysis found only an increased risk in the years that followed, after stopping calcium supplementation, and not during actual calcium supplementation. So, it’s not entirely clear what this finding means for the bigger picture. Especially given the way this study was designed.

But one thing remains clear to me: That’s one more reason not to take calcium supplements.

It’s also important to note that participants who took only vitamin D supplements without calcium, and participants who had a high dietary intake calcium, did not have an increased risk of precancerous polyps.

This finding doesn’t surprise me, as study after study ties higher blood levels of vitamin D to a lower risk of cancer. (In fact, in Thursday’s Daily Dispatch, I’ll tell you about a new Japanese study showing how men and women with higher blood levels of vitamin D run a decreased risk of developing cancer.)

The devil’s in the details

One of the great ironies of modern mainstream medicine is its attitude toward dietary supplements. As I mentioned a moment ago, mainstream practitioners continue to recommend the two supplements that we actually shouldn’t take. And they remain reluctant to recommend the key vitamins and minerals that virtually everyone should take.

Even when the research shows that common prescription drugs reduce levels of key nutrients in the body…

For example, metformin — the otherwise generally effective and safe drug for Type II diabetes — reduces absorption of vitamin B.

Yet, amazingly, doctors still debate whether or not to recommend B vitamin supplements to patients taking metformin. (I recommend taking a high-quality daily B vitamin complex with 12 mcg of vitamin B12 as methylcobalamin, especially if you take metformin.)

Similarly, cholesterol-lowering statin drugs cause the depletion of coenzyme-Q10 (CoQ10), which harms your heart, brain, and energy levels. Yet mainstream practitioners don’t routinely recommend that patients taking statins also take CoQ10 supplements. ( I recommend taking a Ubiquinol CoQ10 softgel supplement. As part of a daily regimen of health promotion and disease prevention, a good dosage is 50 mg daily. For people on statins or recovering from statin poisoning, a recommended dose is in the range of 100 to 200 mg per day.)

Of course, I never recommend taking a statin drug to begin with, as it can cause a host of other problems as well. Plus, maintaining higher cholesterol, especially as you get older offers some significant health benefits, as I’ll explain in Friday’s Daily Dispatch.

Bottom line?

If you’re concerned about maintaining bone health as you get older, skip the calcium supplements and useless once-a-day multivitamins with calcium. Instead, follow these simple tips to build strong bones:

1. Focus on good dietary sources of calcium
You can easily add more calcium to your daily diet. Rich dietary sources include beans, dairy, dark leafy greens (like spinach, kale, collards, and bok choy), oranges, meat, seafood, and sesame and chia seeds. And you don’t need to eat that much. For example, just one cup of milk or yogurt provides 300 to 400 mg of calcium, which is about one-third of your daily requirement.

2. Supplement with the four micronutrients you DO need for strong bones
As we all learned in medical school in the 1970s, vitamin D helps the body absorb and balance calcium in bones and other tissues. In fact, clinical trials for treating women with osteoporosis show that vitamin D is paramount to building and sustaining bone health.

So, I recommend you supplement daily with 10,000 IU of vitamin D year-round. And remember, don’t let the dosage amount in international units (IU) fool you. That unit of measurement can make vitamin D doses “seem” high when they’re not high at all; especially when compared to other dietary supplements or to drugs.)

Magnesium also helps your body absorb calcium from food. I recommend supplementing your diet with 400 mg per day of magnesium daily. Although, for optimal bone health, you may require double that amount. Remember, you can also absorb magnesium through the skin. So — swim in seawater or add Epsom salts (magnesium sulfate) to your bathwater.

Science also shows women with higher levels of omega-3 fatty acids, as found in fatty fish like salmon and sardines, run a lower risk of suffering a hip fracture. Of course, if you don’t like fish, purified omega-3s and fish oil supplements are widely available. I recommend everyone take at least 3 to 4 grams per day of omega-3 fatty acids from fish oil, especially if you don’t eat seafood several times per week.

Last, as I reported in the December 2016 issue of my Insiders’ Cures newsletter, the body also needs vitamin C for bone health. So, make sure to take 250 mg of vitamin C twice a day to help support healthy bones.

3. Get some sun on your face
Now that spring has arrived, and the sun is high enough in the sky to trigger vitamin D production in your skin, go for a nice, daily walk or do some yard work. Just 15 minutes a day of sun exposure will do wonders for your health. Plus, studies show moderate walking and other physical activities can also help build strong bones.

And while outside, I recommend not wearing sunscreen (unless you plan to be outdoors for hours on end). I’ve written before how sunscreen advisories are driven by profit, not science.

One final piece of advice: Check out the latest April and May issues of my Insiders’ Cures newsletter, where I take an in-depth look at the current state of colon health. In fact, I exposed even more deadly risks and complications of colonoscopies — and gave full details the safe, effective, less-invasive screenings to ask your doctor about. (In case you missed it, you can log in to the Subscribers Sign-In via to access my archives. And if you’re not a subscriber, I can’t think of a better time than now to start your journey to better health.)



1. “Calcium and vitamin D supplementation and increased risk of serrated polyps: results from a randomised clinical trial,” Gut ( 3/1/2018

“The association of red blood cell n-3 and n-6 fatty acids with bone mineral density and hip fracture risk in the women’s health initiative.” J Bone Miner Res 2013; 28(3): 505-515