Researchers combined results from multiple studies to understand how vitamin D affects peripheral arterial disease (PAD), a condition where blood vessels in the legs become narrowed. They found that people with PAD tend to have lower vitamin D levels than those without the disease. While vitamin D deficiency appears connected to PAD, the research shows that vitamin D alone isn’t a reliable way to diagnose or predict who will develop this condition. The findings suggest vitamin D may play a role in leg artery health, but other factors are also important.

The Quick Take

  • What they studied: Whether low vitamin D levels are connected to peripheral arterial disease (a condition where arteries in the legs get clogged) and whether checking vitamin D could help doctors diagnose or predict this disease.
  • Who participated: This analysis combined data from multiple previous studies comparing people with leg artery disease to people without it. The exact total number of participants wasn’t specified in the summary.
  • Key finding: People with leg artery disease had vitamin D levels about 2 nanograms per milliliter lower than healthy people. Those with very low vitamin D (below 20 ng/mL) were 52% more likely to have leg artery disease compared to those with normal levels.
  • What it means for you: If you have low vitamin D, it may be worth discussing with your doctor, especially if you have risk factors for leg artery disease. However, a vitamin D test alone cannot reliably diagnose this condition. Maintaining healthy vitamin D levels is still important for overall heart and bone health.

The Research Details

This was a systematic review and meta-analysis, which means researchers searched for all available studies on vitamin D and leg artery disease, then combined the results to find patterns. They looked at studies comparing vitamin D levels between people with and without peripheral arterial disease. The researchers also examined whether vitamin D levels could predict who would develop the disease or help diagnose it.

The analysis included studies that measured vitamin D in the blood and tracked whether people had leg artery disease. Researchers used statistical methods to combine results from different studies, looking at average differences in vitamin D levels and calculating odds ratios (which show how much more likely someone with low vitamin D is to have the disease).

They also tested whether a specific vitamin D cutoff level (20 ng/mL, which is often considered deficient) could accurately identify people with leg artery disease.

By combining multiple studies, researchers can see bigger patterns that might not be obvious in single studies. This approach is stronger than looking at one study alone because it includes more people and different research groups. Understanding whether vitamin D is truly connected to leg artery disease helps doctors know if checking vitamin D levels could be useful for patient care.

This analysis combined published research, which means the quality depends on the original studies included. The researchers found that vitamin D levels were consistently lower in people with leg artery disease across multiple studies, which strengthens the finding. However, some results had wide ranges of uncertainty, suggesting the connection isn’t perfectly clear. The poor performance of vitamin D as a diagnostic test (only 34% specificity) indicates it cannot reliably identify who has the disease.

What the Results Show

The analysis found that people with peripheral arterial disease had vitamin D levels averaging 2.12 nanograms per milliliter lower than people without the disease. This difference was small but consistent across studies.

When researchers looked at vitamin D deficiency specifically (levels below 20 ng/mL), they found that deficient people were 52% more likely to have leg artery disease compared to those with normal or insufficient levels. This suggests a real connection between very low vitamin D and the disease.

However, when researchers tried to predict who would develop leg artery disease based on vitamin D levels alone, the connection weakened after accounting for other risk factors like age, smoking, and diabetes. This suggests that while vitamin D may be involved, it’s not the main driver of the disease by itself.

When testing whether a vitamin D level of 20 ng/mL could diagnose leg artery disease, the test performed poorly. It correctly identified 76% of people with the disease but incorrectly flagged 66% of healthy people as having it, making it unreliable for diagnosis.

The analysis did find one useful result: using a slightly higher cutoff of 19.65 ng/mL, there was a 94% negative predictive value. This means if your vitamin D is above this level, there’s a 94% chance you don’t have leg artery disease. However, this doesn’t mean low vitamin D causes the disease—it just means very low vitamin D is rarely seen without the disease in these studies.

Previous research has shown that vitamin D plays roles in blood vessel health and inflammation, which are both involved in artery disease. This analysis confirms that vitamin D deficiency is more common in people with leg artery disease, supporting the idea that vitamin D matters for this condition. However, unlike some earlier suggestions, this analysis shows vitamin D alone isn’t a strong predictor of who will develop the disease.

The analysis couldn’t determine exact sample sizes from all studies included. The connection between vitamin D and disease weakened when researchers accounted for other risk factors, suggesting vitamin D may just be a marker of other problems rather than a direct cause. The poor diagnostic accuracy means vitamin D testing shouldn’t be used to diagnose leg artery disease. Different studies used different methods to measure vitamin D and define deficiency, which can affect results. The analysis couldn’t prove that low vitamin D causes the disease—only that they’re associated.

The Bottom Line

Maintain adequate vitamin D levels (generally 20-50 ng/mL) through sunlight exposure, diet, or supplements as recommended by your doctor. If you have risk factors for leg artery disease (smoking, diabetes, high cholesterol, or family history), discuss vitamin D status with your healthcare provider as part of overall cardiovascular health. Do not rely on vitamin D testing alone to diagnose or rule out leg artery disease. Confidence level: Moderate—the connection exists but isn’t strong enough to change standard medical practice.

People with risk factors for heart and blood vessel disease should pay attention to vitamin D levels. This includes smokers, people with diabetes, high cholesterol, or family history of heart disease. People living in northern climates or with limited sun exposure should consider vitamin D status. People already diagnosed with leg artery disease may benefit from ensuring adequate vitamin D as part of overall health. This research doesn’t change recommendations for healthy people without risk factors.

If you start improving vitamin D levels, you won’t see immediate changes in leg artery disease. Benefits to blood vessel health from adequate vitamin D develop over months to years. If you’re diagnosed with leg artery disease, vitamin D is one piece of a larger treatment plan that includes exercise, medication, and lifestyle changes.

Want to Apply This Research?

  • Track your vitamin D supplementation or sun exposure weekly, and log any symptoms of poor circulation (leg pain with walking, numbness, or coldness) to share with your doctor at appointments.
  • If your vitamin D is low, set a daily reminder to take a vitamin D supplement or spend 15-30 minutes in midday sunlight several times per week. Log these activities in the app to build consistency.
  • Check vitamin D levels annually through your doctor, especially if you have cardiovascular risk factors. Use the app to track seasonal changes in sun exposure and adjust supplementation accordingly. Monitor and log any new symptoms of leg artery disease to discuss with your healthcare provider.

This research shows an association between low vitamin D and leg artery disease but does not prove that low vitamin D causes the disease. Vitamin D testing should not be used as the sole method to diagnose or rule out peripheral arterial disease. If you have symptoms of leg artery disease (pain, numbness, or weakness in the legs), consult your healthcare provider for proper evaluation and diagnosis. Always discuss vitamin D supplementation with your doctor before starting, especially if you take medications or have kidney disease. This summary is for educational purposes and should not replace professional medical advice.