Researchers used advanced genetic analysis to study whether vitamin B12 deficiency (a condition where your body doesn’t have enough B12) could cause lung diseases. They looked at data from thousands of people and found that having low B12 levels appears to increase the risk of developing pulmonary fibrosis (scarring of the lungs) and eosinophilic asthma (a type of asthma). Interestingly, low B12 was actually linked to lower risk of one type of lung cancer. The study suggests that vitamin B12 plays an important role in lung health, though more research is needed to understand exactly how.

The Quick Take

  • What they studied: Does having low vitamin B12 levels cause or increase the risk of getting different types of lung diseases?
  • Who participated: The study analyzed genetic information from large groups of people worldwide. Researchers didn’t study individual patients directly but instead used existing genetic databases that included information about people with and without lung diseases.
  • Key finding: People with vitamin B12 deficiency had about 16% higher risk of pulmonary fibrosis and 18% higher risk of a specific type called idiopathic pulmonary fibrosis. They also had 39% higher risk of eosinophilic asthma. However, B12 deficiency was linked to lower risk of squamous cell lung cancer.
  • What it means for you: If you have low B12 levels, it may be worth getting checked and treated by a doctor, as maintaining healthy B12 could potentially help protect your lungs. However, this research shows a link, not proof that B12 deficiency causes lung disease, so don’t panic if you have low B12—talk to your doctor about treatment options.

The Research Details

This study used a special type of genetic research called Mendelian randomization, which is like a detective tool for finding cause-and-effect relationships using DNA information. Instead of following people over time, researchers looked at genetic variations that naturally occur in humans and used them to understand whether B12 deficiency actually causes lung disease or if it’s just a coincidence that they happen together.

The researchers gathered genetic data from large databases (called genome-wide association studies) that included information about millions of genetic markers from people around the world. They then used five different statistical methods to analyze this data, making sure their findings were solid and not just flukes. They also tested their results in different ways to make sure they were reliable, similar to how a scientist repeats an experiment to confirm results.

This research approach is important because it helps answer the question ‘does A cause B?’ rather than just ‘are A and B related?’ Regular studies can show that two things happen together, but they can’t always prove one causes the other. By using genetic information, researchers can get closer to understanding true cause-and-effect relationships without needing to follow thousands of people for many years.

The study used multiple statistical methods to check their work, which is a good sign. They also performed sensitivity analyses, which means they tested whether their results held up when they changed their approach slightly. The research was published in Scientific Reports, a well-respected scientific journal. However, because this is a genetic study using databases rather than direct patient observation, the results suggest associations that should be confirmed with additional research.

What the Results Show

The study found clear evidence that vitamin B12 deficiency appears to increase the risk of developing pulmonary fibrosis (scarring of lung tissue). People with B12 deficiency had about 16% higher risk of this condition. When researchers looked specifically at idiopathic pulmonary fibrosis (a more serious form where doctors don’t know the cause), the risk was about 18% higher.

The research also showed that B12 deficiency was linked to a 39% higher risk of eosinophilic asthma, a type of asthma involving certain white blood cells. Importantly, the researchers found that B12 deficiency affects lung fibrosis risk independently of body weight, meaning the effect isn’t just because people with low B12 tend to weigh more.

Interestingly, the results for lung cancer were opposite to what researchers might have expected. People with B12 deficiency actually had about 12% lower risk of developing squamous cell lung cancer. The study found no causal link between B12 deficiency and chronic obstructive pulmonary disease (COPD) or pulmonary embolism (blood clots in the lungs).

The researchers identified a specific gene called CUBN that appears to be important in the relationship between B12 and lung fibrosis. This gene is involved in how your body absorbs and uses vitamin B12. Finding this gene connection suggests that the B12-lung disease link is real and has a biological explanation, not just a statistical coincidence. The study also confirmed that their findings were consistent across different ethnic groups and populations, which strengthens confidence in the results.

This is one of the first studies to use genetic analysis to examine whether B12 deficiency actually causes lung disease. Previous research has shown that people with lung diseases sometimes have low B12 levels, but it wasn’t clear if the low B12 caused the disease or if the disease caused the low B12. This study suggests that B12 deficiency may actually contribute to developing certain lung diseases, which is a new and important finding that adds to our understanding of lung health.

This study has several important limitations to understand. First, it’s based on genetic data and statistical analysis rather than directly observing patients, so while it suggests a cause-and-effect relationship, it doesn’t prove one with absolute certainty. Second, the study couldn’t determine exactly how B12 deficiency might damage the lungs or what the best treatment would be. Third, genetic studies work best in people of European ancestry, so the results may not apply equally to all ethnic groups. Finally, while the study found associations, it doesn’t tell us how much B12 deficiency matters compared to other risk factors for lung disease.

The Bottom Line

Based on this research, maintaining healthy vitamin B12 levels appears important for lung health. If you have symptoms of B12 deficiency (like fatigue, weakness, or numbness), ask your doctor to check your B12 levels. If you’re deficient, treatment with B12 supplements or injections may help. However, this research shows an association, not definitive proof, so it should be one factor among many in your overall health decisions. Talk to your doctor about your individual risk factors for lung disease.

This research is most relevant for people who have low B12 levels, people with a family history of lung disease, older adults (who are more likely to have B12 deficiency), people with digestive disorders that affect nutrient absorption, and vegetarians or vegans (who may have lower B12 intake). People with existing lung conditions like asthma should be especially interested in maintaining good B12 levels. However, this doesn’t mean everyone needs B12 supplements—only those with actual deficiency or risk factors should consider treatment.

If you have B12 deficiency and start treatment, you might feel more energetic within weeks as your B12 levels normalize. However, the protective effects on lung health would likely develop over months to years of maintaining healthy B12 levels. This isn’t a quick fix, but rather part of long-term health maintenance. If you’re concerned about lung disease risk, talk to your doctor about a comprehensive approach that includes B12 status, not just B12 alone.

Want to Apply This Research?

  • Track your B12 levels quarterly if you have a deficiency or risk factors. Record the actual blood test values (measured in picograms per milliliter) and note any symptoms like fatigue or shortness of breath. This helps you and your doctor see if treatment is working and if your lung health might be affected.
  • If you have low B12, set a reminder to take your B12 supplement or schedule your monthly injection. Also track foods high in B12 (like meat, fish, eggs, and fortified cereals) to ensure you’re getting enough from your diet. If you notice new respiratory symptoms like persistent cough or shortness of breath, log these in the app and discuss with your doctor.
  • Create a long-term tracking system that monitors B12 levels annually, tracks respiratory symptoms monthly, and records any new lung-related diagnoses. Set alerts for when it’s time for B12 blood tests and follow-up doctor visits. Over time, this data helps you and your healthcare provider understand if maintaining healthy B12 levels is helping protect your lung health.

This research suggests an association between vitamin B12 deficiency and certain lung diseases but does not prove that B12 deficiency directly causes these conditions. This information is for educational purposes only and should not replace professional medical advice. If you have symptoms of B12 deficiency, lung disease, or are concerned about your respiratory health, consult with a qualified healthcare provider for proper diagnosis and treatment. Do not start, stop, or change any supplements or medications without talking to your doctor first. Individual results may vary based on genetics, overall health, and other factors.