What to Know About Vitamin D and COPD

Medically Reviewed by Paul Boyce, MD on August 22, 2022
3 min read

Many people who have chronic obstructive pulmonary disease (COPD) don’t get enough vitamin D. If that applies to you, you may be able to stave off some complications that COPD can cause if you can get your levels up.

Doctors think there are many reasons why people with COPD often have low vitamin D:

Symptoms keep you indoors. Your body naturally makes vitamin D when you get sunlight. If you have COPD, you may not feel well enough to spend much time outdoors.

You don’t get enough vitamin D from food. It’s hard for many people to get enough of the vitamin through diet alone. Only a few foods are naturally rich in the nutrient. Some things, like cereal and milk, have vitamin D added to them. What's more, COPD can take away your energy and appetite. That can make it even harder to get the vitamin D you need.

You take steroids to treat your COPD. If you take high doses for a long time, steroids can make it harder for your body to absorb vitamin D.

If you don't get enough -- what doctors call “vitamin D deficiency” -- researchers believe it can make you more likely to get lung and airway infections that can cause flares. That can make your symptoms get worse suddenly.

If you avoid these flares, your lungs may stay healthier. Flares make it harder for your lungs to work. Over time, they can make your COPD worse. Serious ones can put you in the hospital. Some can be life-threatening.

Vitamin D also helps keep your bones and muscles healthy. In fact, it can keep you from having bone loss, especially if you're older. It can also prevent and treat osteoporosis.

So if you get enough vitamin D, it may be easier for you to build strength and be active. Both of those things can help you live better with COPD.

If you already have healthy levels of it, you probably don’t need more vitamin D. Studies of people with COPD show that supplements only bring fewer flares to those who don't get enough vitamin D.

Your doctor can check your levels with a blood test. If yours are too low, they can tell you how much you need and the best way to get it.

Some people think an easy way to get more vitamin D is to get more sunlight. While it's true that sun exposure creates vitamin D, be careful. Too much can cause skin cancer and other types of skin damage.

Some foods rich in vitamin D, such as salmon, tuna, sardines, and fortified milk and orange juice, can help. It may make sense to add them to your diet, but it can be hard to reach healthy levels through diet alone.

Another way to get more vitamin D is to quit smoking and avoid secondhand smoke. Cigarette smoke makes it harder for your body to absorb vitamin D.

If your levels are too low, your doctor will probably prescribe supplements to get them where they need to be. There are several kinds. Your doctor can recommend the dose and type that are most likely to help with your COPD and your overall health.

With vitamin D, more is not always better. The highest daily dose that's safe for adults is 4,000 international units (IU). Most people need much less. In fact, too much can cause serious problems.

High doses of vitamin D supplements can trigger a rare, serious condition called vitamin D toxicity. It causes too much calcium to build up in your blood. That can bring:

  • Nausea
  • Vomiting
  • Unplanned weight loss
  • Weakness
  • A need to pee often

In more serious cases, vitamin D toxicity can lead to:

Make sure to talk with your doctor to find out if you need to get more vitamin D.