Research shows that leprosy patients with foot ulcers have significantly lower vitamin D levels than those without ulcers—averaging 13.14 ng/mL compared to 20.18 ng/mL. According to Gram Research analysis of this case-control study of 82 patients, low vitamin D status was independently associated with a 4-fold increased risk of developing these serious wounds, suggesting vitamin D assessment may help prevent or reduce ulcer severity in leprosy.
According to Gram Research analysis, a new study found that leprosy patients with painful foot ulcers have significantly lower vitamin D levels than those without these wounds. Researchers in Indonesia compared 82 leprosy patients—41 with ulcers and 41 without—and discovered that low vitamin D was strongly associated with developing these serious sores. The study also identified a genetic variation that made ulcers more likely. While genetics can’t be changed, vitamin D levels can be improved through diet and supplements, suggesting this could be an important part of treating leprosy-related wounds.
Key Statistics
A 2026 case-control study of 82 leprosy patients found that those with trophic ulcers had vitamin D levels 35% lower than those without ulcers (13.14 ng/mL vs. 20.18 ng/mL, p < 0.001).
In multivariable analysis of 82 leprosy patients, low vitamin D status was independently associated with a 4.15-fold increased odds of developing trophic ulcers (95% CI 1.41-12.24, p = 0.010).
A 2026 case-control study found that a specific vitamin D receptor genetic variant (FokI ff genotype) was independently associated with a 7.86-fold increased odds of trophic ulcers in leprosy patients (95% CI 1.80-34.36, p = 0.006).
Among 82 leprosy patients studied in 2026, serum vitamin D levels showed a weak but significant inverse correlation with ulcer severity (r = -0.312, p = 0.047), suggesting higher vitamin D may be associated with less severe wounds.
The Quick Take
- What they studied: Whether vitamin D levels and specific genetic variations affect the development of painful, hard-to-heal foot ulcers in leprosy patients
- Who participated: 82 adult leprosy patients in Jakarta, Indonesia—41 with trophic ulcers (deep wounds on the feet) and 41 without these ulcers
- Key finding: Leprosy patients with foot ulcers had vitamin D levels that were 35% lower than those without ulcers (13.14 vs. 20.18 ng/mL), and this low vitamin D was independently linked to a 4-fold increased risk of developing ulcers
- What it means for you: If you have leprosy, checking your vitamin D levels and maintaining adequate levels through diet or supplements may help prevent or reduce the severity of foot ulcers. However, this is one study and should be discussed with your doctor before making changes.
The Research Details
This was a case-control study, which means researchers compared two groups of people: those who already had leprosy-related foot ulcers and those who had leprosy but no ulcers. They measured vitamin D levels in blood samples using a precise laboratory test and examined a specific genetic variation called FokI polymorphism using DNA analysis. The researchers then looked at whether differences in vitamin D and genetics were associated with who had ulcers and how severe those ulcers were.
The study took place at a major hospital in Jakarta, Indonesia, where leprosy is more common. All participants were adults with confirmed leprosy diagnoses. The researchers carefully measured ulcer severity using a standardized scoring system called the PUSH scale, which evaluates wound depth, drainage, and tissue type.
This approach is valuable because it allowed researchers to identify associations between vitamin D status, genetics, and ulcer development in a real-world setting. By comparing people with and without ulcers, they could determine whether vitamin D differences existed before the ulcers developed or appeared alongside them.
Case-control studies are particularly useful for studying conditions like leprosy-related ulcers because they’re relatively rare. Rather than waiting years to see who develops ulcers, researchers can efficiently compare people who already have them with similar people who don’t. This design allows researchers to identify potential risk factors and protective factors that might help prevent serious complications.
This study has several strengths: it used objective laboratory measurements rather than self-reported data, it examined both vitamin D levels and genetic factors, and it used statistical methods to determine whether findings were due to chance. The study was published in a peer-reviewed journal (PLoS Neglected Tropical Diseases), meaning other experts reviewed the methods. However, the sample size was relatively small (82 people), and the study was conducted in one location in Indonesia, so results may not apply equally to all populations worldwide.
What the Results Show
The most striking finding was the difference in vitamin D levels between the two groups. Patients with foot ulcers had an average vitamin D level of 13.14 ng/mL, while those without ulcers averaged 20.18 ng/mL—a statistically significant difference (p < 0.001, meaning there’s less than a 0.1% chance this difference occurred by random chance).
When researchers analyzed the genetic variation called FokI polymorphism, they found that a specific genetic variant (the homozygous mutant ff genotype) was more common in patients with ulcers. This genetic variation was independently associated with a nearly 8-fold increased odds of having ulcers.
In the most rigorous analysis (multivariable analysis), both low vitamin D status and the FokI genetic variant remained significantly associated with ulcer presence even when accounting for other factors. Low vitamin D status increased the odds of having ulcers by 4.15 times, while the genetic variant increased odds by 7.86 times.
Additionally, vitamin D levels showed a weak but statistically significant inverse relationship with ulcer severity—meaning patients with higher vitamin D tended to have less severe ulcers, though this relationship was modest.
The study found that vitamin D levels and ulcer severity were weakly correlated (r = -0.312), suggesting that while vitamin D may play a role in ulcer severity, other factors are also important. The genetic variation appeared to be a stronger predictor of ulcer presence than vitamin D levels alone, highlighting that both modifiable (vitamin D) and non-modifiable (genetics) factors contribute to ulcer risk.
Previous research has shown that vitamin D plays important roles in wound healing and immune function, but its specific role in leprosy-related ulcers wasn’t well understood. This study is among the first to directly examine vitamin D levels in leprosy patients with and without these specific types of wounds. The findings align with broader research showing vitamin D deficiency is associated with chronic wounds and impaired healing in other conditions.
The study included only 82 patients from one hospital in Indonesia, so results may not apply to leprosy patients in other regions or populations. The case-control design means researchers measured vitamin D after ulcers had already developed, so they couldn’t definitively prove that low vitamin D caused the ulcers rather than the reverse. The study didn’t account for all possible factors affecting ulcer development, such as nutrition, sun exposure, or treatment adherence. Additionally, the correlation between vitamin D and ulcer severity was weak, suggesting vitamin D is just one of many factors involved.
The Bottom Line
For leprosy patients: Discuss vitamin D screening and supplementation with your healthcare provider as part of comprehensive ulcer prevention and treatment. Vitamin D status is modifiable through diet (fatty fish, fortified dairy), supplements, and safe sun exposure. For healthcare providers: Consider assessing vitamin D status in leprosy patients, especially those at risk for or experiencing trophic ulcers. These recommendations are based on moderate evidence from this single case-control study and should be combined with established leprosy care protocols.
This research is most relevant to leprosy patients, especially those with a history of foot ulcers or at high risk for them. Healthcare providers treating leprosy in tropical and subtropical regions should be aware of these findings. People with other chronic wounds may also benefit from vitamin D assessment, though this study specifically examined leprosy. Those with genetic variations affecting vitamin D metabolism should discuss this with their doctor.
Improving vitamin D status typically takes 4-12 weeks to show measurable changes in blood levels. Benefits for wound healing may take several weeks to months to become apparent, as skin healing is a gradual process. Severe ulcers may require months of comprehensive care even with optimized vitamin D levels.
Frequently Asked Questions
Does vitamin D deficiency cause foot ulcers in leprosy patients?
This study found a strong association between low vitamin D and foot ulcers in leprosy patients, with those having ulcers showing 35% lower vitamin D levels. However, the study design cannot prove vitamin D deficiency directly causes ulcers—only that they’re linked. Other factors also contribute to ulcer development.
Can taking vitamin D supplements help heal leprosy ulcers?
This research suggests vitamin D status may be important for ulcer prevention and severity, but it doesn’t prove supplements will heal existing ulcers. Discuss vitamin D supplementation with your doctor as part of comprehensive ulcer care, which typically involves wound cleaning, pressure relief, and infection prevention.
What vitamin D level should leprosy patients aim for?
This study found patients with ulcers averaged 13.14 ng/mL while those without averaged 20.18 ng/mL. General health guidelines typically recommend vitamin D levels above 20 ng/mL, though optimal levels for leprosy patients specifically require discussion with your healthcare provider.
Is the FokI genetic variant something I can test for?
Yes, genetic testing for the vitamin D receptor FokI polymorphism is available through specialized laboratories. However, since this genetic variation cannot be changed, testing is mainly useful for understanding your ulcer risk and emphasizing the importance of maintaining adequate vitamin D levels.
How long does it take to see benefits from improving vitamin D levels?
Blood vitamin D levels typically improve within 4-12 weeks of supplementation or increased sun exposure. Benefits for wound healing may take several weeks to months, as skin repair is a gradual process. Severe ulcers require comprehensive care beyond vitamin D alone.
Want to Apply This Research?
- Log weekly vitamin D intake (through food and supplements) and track any changes in foot ulcer appearance, pain level, or wound drainage using a 1-10 severity scale. Note sun exposure time when possible.
- Set a daily reminder to take vitamin D supplements if recommended by your doctor, and log it in the app. Track dietary sources of vitamin D (fatty fish, fortified milk, egg yolks) to ensure consistent intake.
- Establish a baseline by photographing any existing ulcers and recording their size and severity. Check vitamin D blood levels every 3 months with your doctor, and track changes in ulcer healing progression monthly using the app’s wound tracking feature.
This research describes associations between vitamin D levels, genetic factors, and leprosy-related ulcers in a specific population. These findings should not replace professional medical advice. If you have leprosy or are experiencing foot ulcers, consult your healthcare provider before starting vitamin D supplements or making other changes to your treatment plan. Vitamin D supplementation may interact with certain medications. This study was conducted in Indonesia and may not apply equally to all populations. Diagnosis and treatment of leprosy-related complications require evaluation by a qualified healthcare professional.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.