Researchers used a special genetic study method to investigate whether low vitamin D causes keloids (thick scars), acne, or hypertrophic scars (raised scars). While previous studies found that people with these skin conditions often had lower vitamin D levels, this new research suggests that vitamin D may not actually cause these problems. The study analyzed genetic data from thousands of people and found no direct causal link between vitamin D levels and developing these three skin conditions. This doesn’t mean vitamin D isn’t important for skin health overall, but it suggests the relationship with these specific conditions is more complicated than previously thought.

The Quick Take

  • What they studied: Whether having low vitamin D in your blood actually causes keloids, acne, or thick raised scars to develop
  • Who participated: The study used genetic information from large databases of thousands of people, rather than recruiting individual participants. This allowed researchers to look at patterns across many different populations.
  • Key finding: The study found no causal relationship between vitamin D levels and any of the three skin conditions studied. Even after using multiple statistical methods to check their work, the results remained consistent and showed no direct connection.
  • What it means for you: If you have acne, keloids, or hypertrophic scars, low vitamin D may not be the cause. While vitamin D is still important for overall health and wound healing, taking vitamin D supplements specifically to prevent or treat these skin conditions may not be effective. Talk to a dermatologist about other proven treatments for your specific skin concern.

The Research Details

This study used a special research method called Mendelian randomization, which uses genetic information to figure out whether one thing actually causes another. Instead of following people over time or doing experiments, researchers analyzed genetic data already collected from large studies involving thousands of people. They looked at genetic variations that affect vitamin D levels and checked whether these same variations were connected to keloids, acne, or hypertrophic scars. This genetic approach is powerful because genes are randomly inherited and can’t be changed by lifestyle factors, which helps prove whether something is truly a cause rather than just an association.

Previous studies showed that people with these skin conditions often had lower vitamin D levels, but those studies couldn’t prove that low vitamin D actually caused the problem. It’s like noticing that people with broken legs often use crutches—the crutches don’t cause the broken leg. This genetic study method is better at finding true causes because it avoids this confusion. By using genetics, researchers can be more confident about whether vitamin D truly causes these skin problems or if the connection is just coincidental.

The study used multiple statistical methods to verify their findings, which strengthens confidence in the results. The researchers carefully selected genetic markers and checked for outliers that might skew results. The consistent findings across different analytical approaches suggest the results are reliable. However, the study used existing genetic databases rather than recruiting new participants, so the quality depends on how well those original studies were conducted. The study was published in a peer-reviewed journal, meaning other experts reviewed it before publication.

What the Results Show

The main finding was that vitamin D levels showed no causal relationship with keloid formation, acne development, or hypertrophic scar formation. For keloids, the statistical analysis showed an odds ratio of 1.15 (meaning a 15% increased odds), but this result was not statistically significant, meaning it could easily be due to chance. For acne, the odds ratio was 0.94 (slightly lower odds), also not significant. For hypertrophic scars, the odds ratio was 1.20, again not reaching statistical significance. In simple terms, none of these results showed a meaningful connection between vitamin D and these skin conditions. When researchers removed potential outliers from their analysis, the results remained unchanged—still showing no causal link.

The study’s strength came from using multiple different statistical methods to analyze the data. All of these different approaches—including inverse-variance weighted analysis, MR-Egger regression, weighted median, simple mode, weighted mode, and MR-PRESSO—consistently showed the same result: no causal relationship. This consistency across multiple methods is reassuring because it suggests the findings aren’t dependent on one particular analytical approach. The researchers also carefully selected genetic markers that truly affect vitamin D levels, which increases confidence that they were measuring the right thing.

This study directly contradicts the assumption from earlier research that low vitamin D causes these skin conditions. Previous observational studies found that people with keloids, acne, or hypertrophic scars tended to have lower vitamin D levels. However, those studies couldn’t prove causation—they could only show an association. This new genetic study suggests that the lower vitamin D levels seen in people with these conditions may be a result of the condition itself, a side effect of treatments, or simply a coincidence rather than a cause. The findings suggest that the relationship between vitamin D and these skin conditions is more complex than a simple cause-and-effect.

The study relied on genetic data from existing databases, so the quality depends on how those original studies were conducted and who participated in them. Genetic studies often include more people of European ancestry, so the findings may not apply equally to all ethnic groups. The study looked at vitamin D levels in the blood but couldn’t examine other factors like sun exposure, diet, or vitamin D supplementation that might affect skin health. Additionally, the study couldn’t identify other genetic or environmental factors that might influence whether someone develops these skin conditions. Finally, while this study shows no causal link, it doesn’t explain why people with these conditions often have lower vitamin D—that question remains unanswered.

The Bottom Line

Based on this research, taking vitamin D supplements specifically to prevent or treat keloids, acne, or hypertrophic scars is not supported by evidence. However, maintaining adequate vitamin D levels is still important for overall bone health, immune function, and general wellness. If you have one of these skin conditions, work with a dermatologist to explore treatments proven effective for your specific problem, such as topical treatments for acne, steroid injections or laser therapy for keloids, or pressure garments for hypertrophic scars. Confidence level: Moderate—this is a well-designed genetic study, but more research is needed to fully understand these relationships.

This research is most relevant for people with keloids, acne, or hypertrophic scars who were considering vitamin D supplementation as a treatment. It’s also important for dermatologists and healthcare providers who advise patients about skin condition management. People with vitamin D deficiency should still maintain adequate levels for overall health, but shouldn’t expect this to resolve these specific skin issues. This research may be less relevant for people without these skin conditions.

If you already have keloids, acne, or hypertrophic scars, vitamin D supplementation would not be expected to improve them based on this research. If you’re concerned about preventing these conditions, vitamin D supplementation is not supported as a preventive strategy based on this study. Any skin condition improvements would require treatments specifically designed for that condition, which typically show results over weeks to months depending on the treatment type.

Want to Apply This Research?

  • Rather than tracking vitamin D specifically for these skin conditions, users should track their actual skin condition status (number of acne lesions, scar appearance, or keloid size) alongside their dermatologist-recommended treatments. Use photos taken in consistent lighting weekly to monitor changes in acne severity or scar appearance.
  • Instead of focusing on vitamin D supplementation for skin problems, users should focus on tracking adherence to dermatologist-recommended treatments like topical medications, steroid injections, or other proven therapies. The app could send reminders for treatment applications and help users log which treatments they’re using and how their skin responds.
  • Create a long-term skin condition tracking system that monitors the effectiveness of actual treatments rather than vitamin D levels. Users can log treatment type, frequency, and skin condition severity weekly. This data helps identify which treatments work best for their individual situation and provides useful information to share with their dermatologist at follow-up appointments.

This research suggests no causal relationship between vitamin D levels and keloids, acne, or hypertrophic scars. However, this study does not mean vitamin D is unimportant for overall health. If you have keloids, acne, or hypertrophic scars, consult with a dermatologist about proven treatment options rather than relying on vitamin D supplementation alone. Do not stop taking vitamin D supplements without discussing it with your healthcare provider, as vitamin D is important for bone health and other bodily functions. This information is for educational purposes and should not replace professional medical advice.