Researchers studied over 5,000 people to understand how different vitamins affect tooth decay. They found that people with higher levels of vitamin B12 were less likely to develop cavities. The study also looked at eight different vitamins and discovered that having good levels of multiple vitamins together seemed to protect teeth better than having just one. While this research suggests vitamin B12 is especially important for tooth health, scientists need to do more studies to confirm these findings and understand exactly how it works.

The Quick Take

  • What they studied: Whether having enough vitamins in your body helps prevent cavities, with special focus on eight different vitamins including B12, vitamin C, and others
  • Who participated: 5,145 people from a large health survey in the United States, of which 1,715 had been diagnosed with cavities
  • Key finding: People with higher vitamin B12 levels had significantly fewer cavities. When researchers looked at all eight vitamins together, having higher levels of multiple vitamins appeared to reduce cavity risk
  • What it means for you: Getting enough vitamin B12 through food or supplements may help protect your teeth, but this doesn’t replace brushing, flossing, or visiting the dentist. Talk to your doctor before starting any supplements

The Research Details

Scientists used information from a large national health survey that tracks what Americans eat and their health conditions. They looked at blood test results showing vitamin levels and dental records showing who had cavities. This type of study is called “cross-sectional” because researchers took a snapshot of people at one point in time rather than following them over years. The researchers used advanced statistical methods to figure out which vitamins were most connected to cavity prevention, and they also used a special technique called Mendelian randomisation to try to determine if low vitamin B12 actually causes cavities or if it’s just a coincidence.

This approach is important because it looks at real people’s actual vitamin levels and dental health rather than just testing vitamins in a lab. By using multiple statistical methods, the researchers could check if their findings were reliable. The Mendelian randomisation technique helps suggest whether vitamin B12 might actually cause cavity protection rather than just being associated with it.

The study included a large number of people (over 5,000), which makes the findings more trustworthy. However, because this is a cross-sectional study, it only shows a snapshot in time and can’t prove that vitamins definitely prevent cavities. The researchers adjusted their analysis for many other factors that affect cavity risk, like age and diet. More research, especially long-term studies where people take vitamins and researchers track their cavities over time, would strengthen these findings.

What the Results Show

When researchers looked at vitamin B12 specifically, people in the three highest groups of B12 levels had fewer cavities compared to people with the lowest B12 levels. This was true even after accounting for other factors like age, diet, and oral hygiene habits. When the scientists looked at all eight vitamins together using a special analysis method, they found that having higher levels of multiple vitamins was connected with lower cavity risk. Vitamin B12 appeared to be the most important vitamin in this protective effect. The researchers also found that inflammation markers in the blood might be one way that vitamin B12 helps protect teeth—basically, vitamin B12 may reduce inflammation in the mouth, which could help prevent cavities.

The study examined other vitamins like A, C, E, and B vitamins, but vitamin B12 stood out as the strongest protector against cavities. The analysis suggested that the combination of multiple vitamins working together might be more protective than any single vitamin alone. The mediation analysis identified four specific inflammatory markers that appeared to be involved in how vitamin B12 protects teeth.

Previous research has suggested that various vitamins play roles in tooth health, but this study is one of the first to look at eight vitamins together and use advanced statistical methods to determine which ones matter most. The finding that vitamin B12 is particularly important aligns with some earlier research suggesting B vitamins support oral health, though most previous studies were smaller or less detailed.

This study only looked at people at one point in time, so we can’t be sure if vitamin B12 prevents cavities or if people with fewer cavities happen to have better nutrition overall. The study was done in the United States, so results might be different in other countries with different diets. The researchers couldn’t prove that vitamin B12 directly causes cavity prevention—they only showed an association. More research where people take vitamin supplements and researchers track their cavities over several years would provide stronger evidence.

The Bottom Line

Based on this research, maintaining adequate vitamin B12 levels appears to be associated with better tooth health (moderate confidence level). This should be part of a complete oral health routine that includes brushing twice daily, flossing, limiting sugary foods and drinks, and visiting the dentist regularly. If you’re concerned about vitamin B12 deficiency, talk to your doctor about getting your levels checked rather than self-treating with supplements.

This research is relevant for anyone concerned about cavity prevention, especially people at higher risk for vitamin deficiencies (older adults, vegetarians, people with certain digestive conditions). People with normal vitamin B12 levels shouldn’t assume they need supplements. Those with specific health conditions or taking medications should consult their doctor before making changes.

If vitamin B12 deficiency is contributing to cavity risk, correcting the deficiency would likely take several weeks to months to show effects. However, cavities develop over time, so you wouldn’t see dramatic changes immediately. Consistent oral hygiene habits remain the most important factor for cavity prevention in the short term.

Want to Apply This Research?

  • Track your vitamin B12 intake daily by logging foods rich in B12 (meat, fish, eggs, dairy, fortified cereals) or any supplements taken. Set a goal to meet the recommended daily intake (2.4 mcg for adults) and monitor weekly totals.
  • Add one B12-rich food to your daily diet (like an egg at breakfast, a glass of fortified milk, or a serving of fish) and log it in the app. If you’re vegetarian or vegan, consider tracking fortified foods or discussing supplements with your doctor.
  • Create a monthly report showing your average B12 intake and correlate it with your dental health notes (like dentist visit results or cavity observations). This helps you see if maintaining better vitamin levels connects with improved oral health over time.

This research suggests an association between vitamin B12 levels and cavity risk, but it does not prove that vitamin B12 supplements will prevent cavities. This information is for educational purposes only and should not replace professional dental or medical advice. Before starting any vitamin supplements, consult with your doctor or dentist, especially if you have existing health conditions or take medications. Regular brushing, flossing, and professional dental care remain the most important strategies for preventing cavities. If you suspect a vitamin deficiency, ask your healthcare provider about testing rather than self-diagnosing.