According to Gram Research analysis, a 2026 study of 44 dark-skinned keloid patients found that those with low vitamin D showed structural changes in their mitochondria and had reduced mitochondrial DNA integrity. Vitamin D positively correlated with mitochondrial health, suggesting adequate vitamin D levels may protect against keloid formation, though the relationship is complex and requires further research.
Keloids are thick, raised scars that form after skin injuries and are especially common in people with darker skin tones. Researchers studied 44 dark-skinned patients with keloids to understand what causes them. They looked at vitamin D levels, cell damage from oxidative stress, and the health of mitochondria (the energy centers inside cells). The study found that people with low vitamin D had subtle changes in their mitochondria, and vitamin D appeared to protect the genetic material inside these energy centers. While the findings are preliminary, they suggest vitamin D may play a role in keloid formation.
Key Statistics
A 2026 study of 44 dark-skinned patients with keloids found that vitamin D positively correlated with mitochondrial DNA integrity, with a correlation coefficient of 0.402 and statistical significance of p = 0.0224.
Among 44 keloid patients examined in 2026, 30 had normal vitamin D levels, 13 had low levels, and 1 was deficient, with structural mitochondrial changes observed in those with low vitamin D.
A 2026 research article found an inverse relationship between mitochondrial DNA integrity and oxidative stress markers in keloid patients, with a correlation coefficient of -0.5225 and p = 0.0036, suggesting oxidative stress damages mitochondrial genetic material.
The Quick Take
- What they studied: Whether vitamin D levels, oxidative stress (cell damage), and mitochondrial health are connected to keloid formation in dark-skinned patients
- Who participated: 44 dark-skinned patients aged 18 to 65 years old who had keloid scars
- Key finding: Patients with low vitamin D showed structural changes in their mitochondria under a microscope, and vitamin D was positively linked to the health of mitochondrial DNA
- What it means for you: Maintaining adequate vitamin D levels may help protect against keloid formation, though more research is needed. If you have dark skin and are prone to keloids, getting your vitamin D checked is worth discussing with your doctor
The Research Details
This was a cross-sectional study, meaning researchers collected information from 44 patients at one point in time rather than following them over months or years. The researchers took tissue samples from keloid scars and blood samples from each patient. They measured vitamin D levels using standard blood tests. They also measured a marker called malondialdehyde (MDA), which indicates oxidative stress or cellular damage. To examine the mitochondria, they used two methods: quantitative PCR to measure the amount of mitochondrial DNA, and transmission electron microscopy to actually see the shape and structure of the mitochondria under extremely high magnification.
This research approach is important because it allows researchers to look at multiple factors at the same time. By examining vitamin D, oxidative stress, and mitochondrial health together, the study can reveal connections between these factors that might not be obvious when studying them separately. The use of electron microscopy is particularly valuable because it shows actual structural changes in the mitochondria, not just measurements on a blood test
This is a small study with only 44 participants, which limits how much we can generalize the findings to all people with keloids. The study is descriptive rather than experimental, meaning it shows associations but cannot prove cause and effect. However, the researchers used rigorous laboratory methods including electron microscopy and quantitative PCR, which are gold-standard techniques. The study was published in a peer-reviewed journal, meaning other experts reviewed it before publication
What the Results Show
Among the 44 patients studied, 30 had normal vitamin D levels, 13 had low levels, and 1 was severely deficient. Surprisingly, oxidative stress markers (MDA levels) were similar across all vitamin D groups, meaning vitamin D status did not directly affect how much cell damage was present. However, when researchers looked at mitochondrial DNA integrity, they found an inverse relationship with oxidative stress: patients with more mitochondrial DNA damage had higher oxidative stress markers. This suggests that oxidative stress may damage the genetic material inside mitochondria. Vitamin D showed a positive correlation with mitochondrial DNA integrity, meaning patients with higher vitamin D levels had healthier mitochondrial DNA.
The most striking finding came from electron microscopy images of the mitochondria. In patients with low vitamin D, the mitochondria appeared smaller than normal and had subtle structural changes. Some mitochondria showed clear double-membrane outlines, while others had less distinct boundaries. These structural changes were not seen as prominently in patients with adequate vitamin D levels. These microscopic observations suggest that vitamin D deficiency may physically alter how mitochondria are shaped and organized
Previous research has suggested that mitochondrial dysfunction and oxidative stress play roles in keloid formation. This study adds new information by showing that vitamin D may protect mitochondrial health in keloid patients. The finding that vitamin D correlates with mitochondrial DNA integrity aligns with other research showing vitamin D’s role in cellular health. However, the lack of difference in oxidative stress markers across vitamin D groups was somewhat unexpected and suggests the relationship between vitamin D and keloid formation may be more complex than previously thought
The study is limited by its small sample size of only 44 patients, which makes it difficult to apply findings to larger populations. The study was cross-sectional, meaning it captured a single moment in time rather than following patients over time, so we cannot determine whether low vitamin D causes keloid problems or if keloid disease causes vitamin D deficiency. The study did not include a control group of dark-skinned people without keloids, making it impossible to know if these mitochondrial changes are specific to keloid disease. Additionally, the study did not measure other factors that might affect mitochondrial health, such as diet, sun exposure, or genetic factors
The Bottom Line
If you have dark skin and are prone to keloids or have had keloid scars, consider having your vitamin D levels checked by your doctor. Maintaining adequate vitamin D through sunlight exposure, diet, or supplementation may help protect against keloid formation, though this study provides preliminary evidence rather than definitive proof. Moderate confidence: the findings are interesting but need confirmation in larger studies before making strong recommendations
This research is most relevant to people with darker skin tones, who are at higher risk for keloids. It may also interest dermatologists who treat keloid disease and researchers studying wound healing. People with lighter skin tones who rarely develop keloids may find this less immediately relevant, though the underlying biology may apply to them as well
If vitamin D deficiency is contributing to keloid formation, correcting vitamin D levels would likely take several weeks to months to show effects. Keloids themselves develop slowly over months to years, so any protective benefit from adequate vitamin D would likely be seen over a longer timeframe, not immediately
Frequently Asked Questions
What is the connection between vitamin D and keloids?
A 2026 study of 44 keloid patients found that vitamin D positively correlates with mitochondrial DNA integrity. Patients with low vitamin D showed structural changes in their mitochondria, suggesting adequate vitamin D may help protect against keloid formation, though more research is needed.
Are keloids more common in people with dark skin?
Yes, keloids are significantly more prevalent in dark-skinned individuals compared to those with lighter skin tones. This 2026 study focused specifically on dark-skinned patients because they face higher keloid risk.
How does oxidative stress relate to keloid disease?
A 2026 study found an inverse relationship between mitochondrial DNA damage and oxidative stress markers in keloid patients. This means higher oxidative stress correlates with more damage to the genetic material inside mitochondria, suggesting oxidative stress may contribute to keloid formation.
Should I take vitamin D supplements if I have keloids?
Discuss vitamin D supplementation with your doctor, especially if you have dark skin and are prone to keloids. A 2026 study suggests adequate vitamin D may help protect mitochondrial health, but this research is preliminary and not yet definitive enough for universal recommendations.
What are mitochondria and why do they matter for keloids?
Mitochondria are the energy centers inside your cells. A 2026 study found that mitochondrial health correlates with vitamin D status in keloid patients, suggesting mitochondrial dysfunction may contribute to excessive scar tissue growth in people with keloids.
Want to Apply This Research?
- Track your vitamin D levels quarterly through blood tests and log them in the app. Record any new keloid formation or changes to existing keloids monthly using photos and measurements
- Set a reminder to get 15 to 30 minutes of midday sun exposure several times per week, or take a vitamin D supplement as recommended by your doctor. Log these activities in the app to maintain consistency
- Create a long-term tracking dashboard that shows vitamin D levels over time alongside keloid development. Use photos to document any changes in keloid appearance or new keloid formation, and correlate these with vitamin D status to identify personal patterns
This article summarizes research findings and is not medical advice. Keloid disease is a complex condition with multiple contributing factors. The findings presented are from a small study and should not be used to make treatment decisions without consulting a qualified dermatologist or healthcare provider. If you have keloids or are concerned about keloid formation, speak with your doctor about appropriate prevention and treatment options tailored to your individual situation. Vitamin D supplementation should only be undertaken under medical supervision.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.