Cancer patients receiving certain chemotherapy drugs often develop painful nerve damage called peripheral neuropathy. Researchers reviewed 11 studies to see if vitamin D levels might affect this side effect. They found that patients with low vitamin D appeared to have a higher risk of developing nerve damage, especially those with breast, cervical, or blood cancers. While the connection looks promising, scientists say more research is needed to confirm whether taking vitamin D supplements could actually prevent or reduce this painful complication.

The Quick Take

  • What they studied: Whether vitamin D levels in the blood affect the chances of developing nerve pain and damage from cancer chemotherapy drugs
  • Who participated: Researchers looked at 11 different studies involving cancer patients (mostly with breast, cervical, blood, and digestive cancers) who were receiving chemotherapy. The studies included patients of various ages receiving different types of cancer drugs
  • Key finding: Patients with low vitamin D levels appeared to have significantly higher rates of developing chemotherapy-related nerve damage compared to those with normal vitamin D levels, particularly in patients receiving specific drugs like paclitaxel, bortezomib, and oxaliplatin
  • What it means for you: If you’re starting chemotherapy, your doctor might want to check your vitamin D levels. While this research suggests low vitamin D may increase nerve damage risk, it doesn’t yet prove that vitamin D supplements will prevent it. Talk to your oncology team before making any changes

The Research Details

This was a scoping review, which means researchers searched through medical databases to find all published studies on vitamin D and chemotherapy nerve damage. They looked at studies published through September 2025 in five major medical databases. The researchers followed strict guidelines called PRISMA-ScR to make sure they did this search fairly and completely.

They found 11 observational studies—these are studies where researchers watch what happens to patients over time rather than randomly assigning them to different treatments. The studies included patients with various types of cancer who were receiving different chemotherapy drugs known to cause nerve damage.

The researchers then analyzed what these studies found about the connection between vitamin D levels and nerve damage risk. They looked for patterns across the different studies to see if low vitamin D consistently appeared linked to worse nerve damage outcomes.

A scoping review is useful for getting a big-picture view of what research already exists on a topic. This approach helps identify patterns and gaps in knowledge before investing in expensive large-scale studies. Understanding whether vitamin D might protect against chemotherapy nerve damage is important because this side effect is very common and causes real suffering for cancer patients

This review followed strict international guidelines for how to conduct and report scoping reviews, which makes it reliable. However, the studies included were observational (watching what happens naturally) rather than randomized controlled trials (the gold standard). This means we can see a connection between low vitamin D and nerve damage, but we can’t be completely certain that low vitamin D actually causes the damage. The researchers themselves noted that more rigorous testing is needed

What the Results Show

Across the 11 studies reviewed, a clear pattern emerged: patients with low vitamin D levels had higher rates of developing chemotherapy-related nerve damage. This pattern was especially strong in patients with breast cancer or cervical cancer receiving a drug called paclitaxel, and in patients with blood cancer (multiple myeloma) receiving drugs like bortezomib and lenalidomide.

Patients receiving oxaliplatin (a drug used for digestive tract cancers) also showed this pattern—those with low vitamin D had significantly more nerve damage. The researchers found that vitamin D levels could potentially predict who would develop this complication, suggesting it might be a useful marker doctors could check before treatment starts.

The findings suggest that vitamin D may protect nerves through several mechanisms: it may reduce inflammation, help nerves repair themselves, and protect nerve cells from damage. However, the studies reviewed didn’t test whether actually giving patients vitamin D supplements would prevent or reduce nerve damage.

The review found that the connection between vitamin D and nerve damage appeared consistent across different cancer types and different chemotherapy drugs, suggesting this might be a general protective effect rather than something specific to one drug or cancer type. The researchers noted that vitamin D’s protective properties—its ability to fight inflammation and support nerve health—could explain why deficiency increases risk

This is one of the first comprehensive reviews bringing together evidence on this specific topic. Previous research has shown that nutrition affects cancer treatment side effects, and separate research has shown vitamin D’s importance for nerve health. This review connects those two areas and suggests vitamin D may be particularly important for cancer patients receiving nerve-damaging chemotherapy

The main limitation is that all 11 studies were observational—they tracked what happened to patients but didn’t randomly assign some to get vitamin D and others not to. This means we can see a connection but can’t prove vitamin D deficiency causes the nerve damage. Additionally, the studies used different ways to measure vitamin D levels and define nerve damage, making direct comparisons difficult. The review also couldn’t determine the ideal vitamin D level for protection or whether supplements would actually help

The Bottom Line

Based on this evidence, doctors might consider checking vitamin D levels before starting chemotherapy, especially for patients receiving drugs known to cause nerve damage. However, there is currently insufficient evidence to recommend vitamin D supplements specifically to prevent nerve damage. If you have low vitamin D, your doctor may recommend supplementation for general health reasons. Confidence level: Moderate—the pattern is clear, but we need stronger evidence before making specific treatment recommendations

This research is most relevant to cancer patients about to receive chemotherapy drugs known to cause nerve damage (paclitaxel, oxaliplatin, bortezomib, lenalidomide, and vinca alkaloids). It’s also important for oncologists and cancer care teams. People with other conditions should not assume vitamin D supplements will help with nerve problems unless their doctor recommends it for their specific situation

Nerve damage from chemotherapy typically develops during or shortly after treatment. If vitamin D does provide protection, the benefit would likely appear over weeks to months of treatment. However, we don’t yet know if starting vitamin D supplements after treatment has already begun would help, or if prevention requires adequate levels before treatment starts

Want to Apply This Research?

  • If your doctor checks your vitamin D level before chemotherapy, track this baseline number and any follow-up measurements. Also track the timing and severity of any nerve symptoms (tingling, numbness, pain) in your hands and feet using a simple 0-10 scale, noting which week of treatment symptoms appeared
  • Work with your oncology team to get your vitamin D level checked before starting chemotherapy. If it’s low, discuss whether supplementation makes sense for you. Keep a simple log of any nerve-related symptoms and your vitamin D supplement intake (if prescribed) to share with your care team
  • Create a monthly check-in where you record your vitamin D supplement intake (if taking one), your current vitamin D level (if retested), and any changes in nerve symptoms. Share this with your oncology team at each visit to help them monitor how you’re tolerating treatment

This review summarizes research on the connection between vitamin D and chemotherapy nerve damage, but it does not constitute medical advice. Vitamin D supplementation decisions should only be made in consultation with your oncology team, as they understand your specific cancer type, treatment plan, and overall health. Do not start, stop, or change any supplements without discussing it with your doctor first. This research is preliminary and should not be used to make treatment decisions without professional medical guidance.