A 2026 cohort study of over 515,000 adults found that people with vitamin D deficiency are 62% more likely to develop varicose veins within five years compared to those with adequate vitamin D levels. According to Gram Research analysis, this large real-world study suggests that maintaining healthy vitamin D status may help reduce varicose vein risk, though the research shows association rather than proof of causation. The connection was even stronger in older adults and people with diabetes.
A large study of over 500,000 adults found that people with vitamin D deficiency are significantly more likely to develop varicose veins—those bulging, twisted veins that often appear in the legs. Researchers compared people with consistently low vitamin D levels to those with healthy levels and tracked them for five years. The findings suggest that maintaining adequate vitamin D may help protect against varicose veins, though more research is needed to prove vitamin D supplements can actually prevent them. This is one of the largest studies to examine this connection.
Key Statistics
A 2026 cohort study of 515,302 adults aged 40 and older found that vitamin D deficiency was associated with a 62% increased risk of developing varicose veins over five years (hazard ratio 1.62, 95% CI 1.50-1.75).
In the same 2026 study of over 515,000 adults, the association between vitamin D deficiency and varicose veins was even stronger in older adults and individuals with diabetes, suggesting age and diabetes may amplify the connection.
According to a 2026 propensity score-matched cohort study involving 257,651 matched pairs, vitamin D deficiency was significantly associated with increased risk of varicose veins with complications including ulceration and inflammation.
The Quick Take
- What they studied: Whether people with low vitamin D levels are more likely to develop varicose veins compared to people with normal vitamin D levels
- Who participated: Over 515,000 adults aged 40 and older who had their vitamin D levels measured at least twice between 2010 and 2023. After careful matching to make groups comparable, 257,651 people were in each group (low vitamin D and normal vitamin D)
- Key finding: People with vitamin D deficiency were 62% more likely to develop varicose veins within five years compared to people with adequate vitamin D levels. This increased risk was even higher in older adults and people with diabetes
- What it means for you: Getting enough vitamin D through sunlight, food, or supplements might help reduce your risk of developing varicose veins. However, this study shows an association, not proof that vitamin D prevents varicose veins. Talk to your doctor about your vitamin D levels and whether supplementation is right for you
The Research Details
This was a large retrospective cohort study, meaning researchers looked back at medical records from real patients over time rather than conducting a new experiment. They used a special technique called propensity score matching to create two groups that were as similar as possible except for their vitamin D levels. One group had consistently low vitamin D (measured at 19.9 ng/mL or lower on two separate tests), while the other group had healthy vitamin D levels (30.0 ng/mL or higher on two tests). The researchers then followed both groups for five years to see who developed varicose veins.
The study used data from the TriNetX Global Collaborative Network, which includes medical records from millions of patients across many hospitals and clinics worldwide. This real-world approach is valuable because it reflects what actually happens in everyday medical practice, not just what happens in controlled laboratory settings. The researchers used a special statistical method called Cox proportional hazards models to calculate the risk of developing varicose veins in each group.
A landmark design was applied, meaning they started counting from one year after the vitamin D measurements were taken. This helps ensure that the vitamin D measurements came before the varicose veins developed, which is important for understanding cause and effect.
This study design is important because it uses real patient data from a huge number of people, making the results more applicable to everyday life than smaller studies. The propensity score matching technique helps ensure that differences in varicose vein risk are due to vitamin D levels rather than other factors like age, weight, or existing health conditions. The large sample size gives researchers confidence that the findings are reliable and not due to chance
Strengths of this study include its very large sample size (over 515,000 people), use of real medical records, and careful matching of comparison groups. The study was published in a peer-reviewed journal, meaning other experts reviewed it before publication. However, this is an observational study, so it can show that vitamin D deficiency and varicose veins are connected but cannot prove that low vitamin D causes varicose veins. The study relied on medical records, which may not capture all cases of varicose veins. Additionally, vitamin D levels were measured at specific points in time, and they can change over the years
What the Results Show
The main finding was striking: people with vitamin D deficiency had a 62% higher risk of developing varicose veins over five years compared to people with adequate vitamin D levels (hazard ratio of 1.62). This means that if 100 people with normal vitamin D developed varicose veins, approximately 162 people with vitamin D deficiency would develop them. The difference was statistically significant, meaning it’s very unlikely to have occurred by chance.
The increased risk was even more pronounced in certain groups. Older adults with vitamin D deficiency had an even higher risk of developing varicose veins. People with diabetes who also had vitamin D deficiency showed a particularly strong association with varicose vein development. These findings suggest that age and diabetes may make the connection between vitamin D and varicose veins even stronger.
The study also examined varicose veins with complications, such as those with ulceration (open sores) or inflammation. People with vitamin D deficiency showed increased risk for these more serious forms of varicose veins as well, though the study provided limited details on these secondary outcomes.
Beyond the primary outcome, the study examined varicose veins that came with complications like ulceration and inflammation. The association between vitamin D deficiency and these more serious forms of varicose veins was also statistically significant, suggesting that vitamin D deficiency may be linked not just to developing varicose veins but to developing more problematic cases
Previous research on this topic has been limited, mostly involving small studies or cross-sectional designs (which only look at one point in time). According to Gram Research analysis, this is one of the largest studies to examine the connection between vitamin D deficiency and varicose veins. The findings align with biological plausibility—vitamin D plays important roles in blood vessel health and inflammation regulation, so it makes sense that deficiency could affect vein function. However, most previous studies were too small to draw firm conclusions
This study cannot prove that vitamin D deficiency causes varicose veins, only that they are associated. People with low vitamin D might differ in other ways not captured in the data (like physical activity levels or diet). The study relied on medical records, so some cases of varicose veins may have gone undiagnosed or unrecorded. Vitamin D levels can change over time, but this study only measured them at specific points. The study included mostly people aged 40 and older, so results may not apply to younger adults. Finally, the study was observational, meaning researchers couldn’t control all variables like they could in a randomized controlled trial
The Bottom Line
Based on this research, maintaining adequate vitamin D levels appears prudent for overall health, including potential vein health. Current guidelines recommend 600-800 IU daily for most adults, though some experts suggest higher amounts. Get your vitamin D level checked if you have risk factors for varicose veins (family history, prolonged standing, obesity). If you have vitamin D deficiency, work with your doctor to correct it through sunlight exposure, dietary sources, or supplements. However, this study shows association, not causation, so vitamin D supplementation alone is not proven to prevent varicose veins. Confidence level: Moderate—the study is large and well-designed, but causality cannot be established from observational data
This research is particularly relevant for people aged 40 and older, those with family histories of varicose veins, people with diabetes, and anyone with known vitamin D deficiency. It’s also important for healthcare providers managing venous disease. People without varicose vein risk factors should still maintain adequate vitamin D for overall health, but this study doesn’t suggest they need special supplementation solely to prevent varicose veins
If vitamin D deficiency is contributing to varicose vein risk, correcting it would likely take months to show effects, as vein changes develop gradually. The study tracked people for five years, so benefits would likely accumulate over time rather than appearing immediately. Don’t expect varicose veins to disappear from vitamin D supplementation alone, but maintaining healthy levels may help prevent new ones from developing
Frequently Asked Questions
Does low vitamin D cause varicose veins?
A 2026 study of over 515,000 adults found that people with vitamin D deficiency have a 62% higher risk of developing varicose veins, but this shows association, not causation. The research suggests vitamin D may be relevant to vein health, but more studies are needed to prove supplementation prevents varicose veins.
How much vitamin D do I need to prevent varicose veins?
Current guidelines recommend 600-800 IU daily for most adults. The study defined adequate vitamin D as 30 ng/mL or higher. However, this research doesn’t prove that reaching these levels will prevent varicose veins—it only shows an association. Consult your doctor about your individual needs.
Can vitamin D supplements get rid of existing varicose veins?
This study doesn’t address whether vitamin D can treat existing varicose veins, only whether deficiency increases the risk of developing them. Varicose veins typically require medical treatment like compression stockings or procedures. Talk to your doctor about treatment options for existing varicose veins.
Who is most at risk for varicose veins from vitamin D deficiency?
The 2026 study found the connection was strongest in adults over 40 and people with diabetes. If you’re in these groups with low vitamin D, getting your levels checked and corrected may be especially important for overall vascular health.
How long does it take for vitamin D to affect varicose vein risk?
The study tracked people for five years, suggesting benefits would accumulate over months to years rather than weeks. Correcting vitamin D deficiency takes time, and vein changes develop gradually. Consistent supplementation and monitoring over several months is needed to see potential effects.
Want to Apply This Research?
- Track your vitamin D supplementation (dose and frequency) alongside any new symptoms of varicose veins (leg heaviness, visible veins, swelling). Record this weekly to identify patterns over months
- If your vitamin D is low, set a daily reminder to take your supplement at the same time each day. Also increase sun exposure (10-30 minutes daily) and eat more vitamin D-rich foods like fatty fish, egg yolks, and fortified milk. Log these activities in the app
- Have your vitamin D level rechecked every 3-6 months after starting supplementation to ensure it reaches adequate levels (30 ng/mL or higher). Track leg symptoms monthly using a simple scale (none, mild, moderate, severe). Share this data with your doctor to monitor your progress
This research shows an association between vitamin D deficiency and varicose veins but does not prove causation. These findings should not replace professional medical advice. If you have varicose veins, leg pain, swelling, or concerns about your vitamin D levels, consult your healthcare provider for proper diagnosis and treatment. Do not start or stop vitamin D supplementation without discussing it with your doctor, especially if you take medications or have existing health conditions. This article is for educational purposes and should not be used for self-diagnosis or self-treatment.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.