Colorectal cancer (which includes cancers of the colon and rectum) is one of the most common types of cancer around the world. In fact, it ranks second in men and third in women globally. In the U.S. alone, the risk of developing colorectal cancer over a lifetime is about 1 in 24 for men and 1 in 26 for women.
With these alarming numbers, scientists and health experts are constantly on the lookout for ways to reduce this risk. One promising area of research? Vitamin D.
A recent review published in April 2025 in the journal Nutrients has sparked interest, suggesting that vitamin D may play a significant role in lowering the risk of colorectal cancer. Let’s take a closer look.
What Was This Study About?
This wasn’t a single experiment but a review of 50 different studies that looked at the connection between vitamin D and colorectal cancer. Out of over 10,000 studies, researchers narrowed it down to those that involved adults who either had colorectal cancer (or were at high risk) or were vitamin D deficient. They also focused on studies where participants took vitamin D supplements.
What Was This Study About?
This wasn’t a single experiment but a review of 50 different studies that looked at the connection between vitamin D and colorectal cancer. Out of over 10,000 studies, researchers narrowed it down to those that involved adults who either had colorectal cancer (or were at high risk) or were vitamin D deficient. They also focused on studies where participants took vitamin D supplements.
What Did They Discover?
Vitamin D is known for supporting bone health, but it turns out it does much more. According to the review, vitamin D helps:
Support immune function
Reduce inflammation
Maintain gut health
Regulate blood sugar and blood pressure
Slow down abnormal cell growth
Promote the death of damaged or harmful cells
Inhibit the growth of blood vessels that feed tumors
One particular finding stood out:
Women who consumed the highest levels of vitamin D were 58% less likely to develop colorectal cancer compared to those with the lowest intake. Other studies showed similar trends with both dietary sources and supplements.
Even more encouraging, vitamin D was linked to a lower risk of developing polyps and adenomas, which are often early signs of colorectal cancer.
Why Are So Many People Deficient?
It’s estimated that 30% to 50% of people globally are low in vitamin D. That number may be even higher in certain groups, especially:
People living in colder regions with limited sunlight
Individuals with darker skin
Women
Older adults
Those with poor dietary habits or limited access to nutritious food
People dealing with obesity, diabetes, or chronic inflammation
Vitamin D is often called the “sunshine vitamin” because our skin produces it when exposed to sunlight. But long winters, indoor lifestyles, pollution, and even sunscreen use can all limit how much vitamin D our body makes.
How Can You Increase Your Vitamin D Levels?
Here are some simple, effective ways to boost your vitamin D naturally:
Spend time in the sun (preferably during mid-morning or late afternoon for 10–30 minutes, depending on skin type)
Eat vitamin D-rich foods, such as:
Fatty fish (salmon, tuna, sardines)
Egg yolks
Mushrooms
Fortified foods like dairy products and orange juice
Consider taking a supplement, especially during winter or if your levels are low (but consult a doctor or dietitian first)
The Mediterranean Diet Connection
The review also found that people who followed diets rich in fruits, vegetables, whole grains, healthy fats, and lean proteins—such as the Mediterranean diet—tended to have better vitamin D levels and lower inflammation overall. This type of eating pattern may offer more protective benefits than focusing on one single nutrient.
Final Thoughts
The findings from this study are clear: Maintaining healthy vitamin D levels could significantly reduce your risk of developing colorectal cancer.
While more research is needed to determine the ideal dosage and long-term impact, one thing is certain—taking care of your vitamin D intake is a simple and powerful step toward better health.
If you haven’t checked your vitamin D levels lately, consider asking your healthcare provider for a blood test. And whether through sunlight, diet, or supplements, make sure you’re getting enough of this essential nutrient.
Stay informed. Stay healthy.
And don’t forget—sometimes the smallest changes, like adding more sunshine and salmon to your routine, can make the biggest difference.
