Transcript for Can Vitamin D help prevent colon cancer?
We have a "Gma" health alert. We know vitamin D is god for your bones. It may lower your risk of colon cancer. Nutritionist Maya feller has more. A big study, huge international study. What does it tell us about vitamin D? This found an association between higher levels of vitamin D in your blood and colon cancer risk. The association was stronger for women than it was for men. However, they found that when both women and men were deficient they were 30% -- 31% more likely to have colon cancer. You know, colon cancer is the third most common cancer in the country. This is big. Really huge. So we want to do a little true/false. You guys will help us out. You have your paddles. Audience involvement here. We're going to ask a question. Let us know what you think, true or false. Here we go. Broccoli has more vitamin D than milk? True or false, guys? Broccoli, more vitamin D? False. Absolutely false. But, you know, broccoli is healthy. However, it is not a source of vitamin D that you should be looking toward. All right. Sorry, guys. Now you know. Important to know. All right, so spending time in the sun a recommended way to increase vitamin D? What do you guys think? True or false? Oh, false. Look, in the past, I know, sorry. In the past we used to say go sit in the sun but now with everything that we know about skin cancer it's not our first line. We're getting a "D" in our vitamin D lesson but learning and it's important. Last thing I want to ask you is how much vitamin D do we need? What does it look like for us. The average American under the age of 70 needs 600 ius of vitamin D per day. This is four ounces of salmon right here. That's giving you your full recommendation for vitamin D. This is my absolute favorite. Port Bella, 950 ius. One delicious sandwich and you're done. Supplements should you want. Right? I'm always going to say talk to your dietician or doctor before you supplement.
This transcript has been automatically generated and may not be 100% accurate.