Vitamin D: What you should know

It’s important to protect your skin from the cancer-causing ultraviolet light from the sun. But the sun also provides vitamin D, an important vitamin that can help lower your cancer risk.

So, what’s the right answer? Should you rush outside and try to soak up more vitamin D?

Our in-house sun expert says no.

“Vitamin D is critical to good health,” says Susan Y. Chon, M.D., associate professor in the Department of Dermatology at MD Anderson. “However, there are safer ways to increase your vitamin D levels without laying in the sun.”

So, why do we need vitamin D? Well, it’s the main building block for maintaining bone health. Without it, you can develop thin and brittle bones. Vitamin D also can boost your immune system to help fight off germs, bacteria and diseases, including certain cancers.

Vitamin D and the sun

People tend to think of sunshine when they think of vitamin D, and with good reason. When UV rays come in contact with the skin, it triggers the creation of vitamin D.

Researchers believe most people can absorb enough vitamin D from just your “typical” outdoor comings and goings.

But, while absorbing the sun’s rays can have health benefits, it can lead to skin cancer.

“On a hot summer day, unprotected skin can be damaged in as little as 15 minutes,” Chon says. “There’s no safe amount of time you can stay in the sun without increasing your cancer risk.”

To avoid skin cancer, Chon recommends getting your daily fill of vitamin D from foods and, if necessary, supplements.

Add vitamin D to your diet

A handful of foods provide a large serving of this vitamin, including:

• Fish: One serving (about three ounces) of certain types of fish can give you a healthy dose of vitamin D. This includes:
  • Salmon: Provides 447 IUs per serving
  • Mackerel: Provides 388 IUs per serving
  • Tuna: Provides 154 IUs per serving
• Milk: Milk really does a body good. Just one cup of whole, reduced fat or non-fat milk is fortified with vitamin D and provides 115 – 124 IUs. 

Vitamin D needs aren’t one-size-fits-all

Not sure how much vitamin D your body requires? Use this breakdown from the Food and Nutrition Board. 

• Birth to 12 months: 400 IUs
• Age  1 to 70: 600 IUs
• Age 70 and older: 800 IUs

So, most people can get their daily quota of vitamin D by drinking a cup of milk and eating a three-ounce serving of salmon.

Some may need supplements

If you have limited sun exposure, eat a vegan diet or have liver or kidney disease or any other concerns, you should consider having your vitamin D levels checked. All it takes is a simple blood test for your doctor to determine if you’re receiving too much, not enough or just the right amount of this important nutrient.

If you aren’t getting enough through your diet, your doctor may recommend you take a daily vitamin D supplement. You may need supplements if you:

• Have milk allergies
• Are lactose intolerant
• Stick to a vegetarian diet
• Get limited sun exposure

There’s no doubt that vitamin D is vital when it comes to healthy bones and preventing diseases like cancer. But, there’s no need to sacrifice sun safety (like skipping the sunscreen or spending countless hours soaking in the rays) to get your fill.

Request an appointment at MD Anderson's Lyda Hill Cancer Prevention Center online or call 877-632-6789.