When we talk about cancer, most people first think of something scary and distant that happens to others. Unfortunately, the numbers tell a different story. According to the World Health Organization, more than 19.3 million people are diagnosed with cancer every year, with 1.9 million of them having colon and rectal cancer. This is the third most common cancer in the world, yet one that can be greatly reduced with good habits and timely measures.

There is a lot of talk about healthy eating, exercise, and avoiding alcohol and tobacco. Less is said about one simple, almost everyday supplement that you may already have at home, calcium. Yes, the same calcium you know as a builder of bones and teeth. Research shows that it can do even more, reducing the risk of colon cancer by up to 30%.

What do studies say about calcium and cancer?

A study published in the prestigious National Cancer Institute Journal in 2024 examined how different people responded to dietary supplements with calcium. The results were surprising: those who took calcium supplements had a 31% lower risk of developing colon cancer compared to those who did not.

Particularly interesting is that only calcium from food, such as from milk, cheese, or yogurt, did not provide the same protection. The difference occurred when people started taking calcium in the form of a dietary supplement. The strongest effect was seen in those who consumed around 500 mg of calcium per day, which is about half of the recommended daily amount for an adult.

Is the effect of calcium proven?

Here, science gets a bit complicated. Some studies, such as the one published by the University of Auckland in 2013, did not find a strong connection between calcium and a lower risk of cancer. In this study, calcium did not show protection against cancer in general, nor against breast cancer. However, interestingly, they found signs that it could help with prostate cancer, which is the most common form of cancer in men.

Looking at a broader perspective, researchers agree on one thing: calcium has potential, but it is not a miraculous cure. The effect depends on the individual, their diet, lifestyle, and even whether they have enough vitamin D in their body to help calcium absorb better.

How can you help yourself with home remedies today?

In folk medicine, calcium has long been used as something that strengthens the body. In the past, people would drink water in which they soaked eggshells for a few days. Today we know that eggshell indeed contains almost 95% calcium in the form of calcium carbonate. Although experts do not recommend this trick for daily use (due to bacteria), it shows us that people have been looking for ways to help themselves with natural sources for centuries.

If you want to ensure an adequate intake of calcium safely and inexpensively, you can opt for:

• milk products - a glass of milk contains around 250 mg of calcium,
  
  
• leafy green vegetables - a cup of broccoli has approximately 60 mg,
  
  
• sardines - one can contains over 300 mg of calcium,
  
  
• almonds - a handful of almonds (30 g) has around 75 mg of calcium.

While food contains calcium, studies show that a supplement in tablet form is more effective for cancer prevention. The price of such supplements is low - around 5 to 10 euros for a month of intake - which is significantly less than the costs of treatment if the disease progresses.

Why does calcium help?

Scientists are still not entirely sure, but there are several theories. One theory suggests that calcium binds harmful substances in the intestines and eliminates them from the body before they can damage cells. Another theory suggests that calcium helps cells in the intestines to renew and repair minor damages faster, which could otherwise lead to cancer.

To put it simply, calcium acts as a shield in the intestines, preventing harmful substances from lingering where they could cause the most damage.

What about risks?

As with everything, balance is important. Too much calcium can cause kidney problems or constipation. Therefore, experts recommend that adults do not exceed 2000 - 2500 mg of calcium per day. The safest dose for supplements is between 500 and 1000 mg per day.

If you are already taking other medications, it is good to consult a doctor before starting calcium supplementation. For most healthy individuals, calcium supplementation is considered one of the safer and more accessible forms of prevention.

In 2020, a large campaign on the importance of calcium in preventing bone diseases and cancer took place in the USA. According to the National Institutes of Health, the sales of calcium supplements increased by more than 15% that year, as many people started to care more about their health due to the pandemic.

By 2025, many European countries have incorporated recommendations on calcium into their public health guidelines. For example, in the Netherlands, people over 50 were recommended to take calcium supplements together with vitamin D, as they found that these individuals had a 20% lower likelihood of developing colon cancer compared to those who did not take it.

How to link science and traditional knowledge?

In traditional practice, the rule is: what strengthens bones also strengthens the inside. This rule aligns well with today's research. Calcium is not just a building block for bones; it has a broader effect on the body. When there is enough of it, our cells behave more orderly and are less likely to mutate (meaning they do not change into something harmful).

Looking more broadly - folk wisdom and modern science align in this case. Calcium is inexpensive, accessible, and can indeed reduce the risk of one of the most dangerous diseases of modern times.

A small step with a big impact

Cancer is a disease that we all fear, but the good news is that we can do a lot ourselves to reduce the risk. Calcium as a dietary supplement is not a miracle, but studies show that with a daily dose of 500 mg, the risk of colon cancer can be reduced by up to 30%. This is a number that should not be overlooked.

If we add to this healthy eating, exercise, and avoiding harmful habits, we can significantly increase our chances for a long and healthy life. Sometimes the solution is simpler than we think. Perhaps it is truly hidden in just one small calcium tablet a day.