Low Vitamin D Levels Up Risk of Chemotherapy-Induced Neuropathy
Women with low vitamin D levels who were receiving Taxol (chemical name: paclitaxel) to treat breast cancer had a higher risk of neuropathy than women with sufficient vitamin D levels.
The research was published in the November 2023 issues of the Journal of the National Comprehensive Cancer Network. Read “Vitamin D Insufficiency as a Risk Factor for Paclitaxel-Induced Peripheral Neuropathy in SWOG S0221.”
What is neuropathy?
Neuropathy, also called peripheral neuropathy, is damage to nerves that causes tingling, numbness, or pain in the area that’s affected. Neuropathy often affects your hands and feet, but other parts of your body can be affected.
When neuropathy is caused by chemotherapy, it’s called chemotherapy-induced peripheral neuropathy, or CIPN.
Certain chemotherapy medicines, including Taxol, are known to cause neuropathy.
There are two main types of neuropathy:
sensory neuropathy, which causes pain, numbness, and tingling
motor neuropathy, which causes muscle weakness and can affect balance and the ability to walk and move
Listen to The Breastcancer.org Podcast episode with Dr. Michael Stubblefield explaining how chemotherapy can cause neuropathy.
Medicines such as Cymbalta (chemical name: duloxetine), Neurontin (chemical name: gabapentin), and Lyrica (chemical name: pregabalin) can help ease neuropathy in some people. Acupuncture and massage may also help.
Newer research suggests that cannabis may help treat neuropathy.
Listen to the episode of The Breastcancer.org Podcast featuring Dr. Marisa Weiss, Breastcancer.org founder and chief medical officer, discussing her research on using cannabis to ease peripheral neuropathy caused by chemotherapy.
Earlier research suggests that there are several risk factors for chemotherapy-induced neuropathy, including:
having diabetes, especially if sugar levels aren’t well controlled
abusing alcohol
having an autoimmune disease, such as lupus or rheumatoid arthritis
Black women are also much more likely to develop neuropathy after chemotherapy for breast cancer than white women. It’s not clear why this happens.
Other studies have suggested that low levels of certain vitamins may increase the risk of neuropathy, but more research is needed.
About the study
In this study, the researchers wanted to know if low vitamin D levels were a risk factor for neuropathy in women receiving Taxol for early-stage breast cancer.
They used information collected as part of the SWOG S0221 clinical trial, which was comparing six dosing schedules of the standard chemotherapy regimen of Adriamycin (chemical name: doxorubicin) and Cytoxan (chemical name: cyclophosphamide) followed by Taxol after breast cancer surgery. This regimen is commonly called AC-T.
This analysis included information from 1,191 women diagnosed with early-stage breast cancer. The women’s average age was 51.1 years. About 84% of the women were white and 9% were Black.
Before chemotherapy started, 33% of the women had low vitamin D levels.
During chemotherapy:
16.4% of the women developed grade 3 or more severe sensory neuropathy
17.1% of the women developed grade 3 or more severe sensory or motor neuropathy
Side effects are classified into five levels of severity:
1 is mild
2 is moderate
3 is severe
4 is life-threatening
5 is death-causing
The researchers’ analysis showed that women with low vitamin D levels were 65% more likely to develop neuropathy than women with sufficient vitamin D levels.
Black women were more likely to develop neuropathy than white women. Black women also were more likely to have low vitamin D levels than white women:
77.1% of Black women had low vitamin D levels
28.2% of white women had low vitamin D levels
The researchers also did an experiment in mice and found that low vitamin D levels caused nerve damage. Mice with low vitamin D levels that received Taxol had even more severe nerve damage.
“Pre-treatment vitamin D insufficiency is associated with a higher risk of [chemotherapy-induced peripheral neuropathy] from paclitaxel,” the researchers concluded. “Prospective trials are needed to investigate the potential effectiveness of vitamin D supplementation for [chemotherapy-induced peripheral neuropathy] prevention.”
What this means for you
If you’re scheduled to receive a chemotherapy regimen that includes Taxol to treat breast cancer, this study adds more evidence to support the idea that low vitamin D levels can increase your risk for neuropathy.
What we don’t know yet is whether taking vitamin D supplements can help reduce the risk of neuropathy.
Right now, it makes sense to ask your doctor to check your vitamin D levels before you start chemotherapy. If your levels are low, ask your doctor whether a supplement makes sense for you.
It’s important to know that some supplements and vitamins can interact with certain cancer medicines. So it’s extremely important to talk to your doctor before you start taking a supplement or increase the dose of any supplement you take.
It’s also important to know that too much vitamin D can lead to too much calcium in the blood. Over time, this can damage soft tissues, such as the lungs, and may cause kidney stones.
Together, you and your doctor can decide if taking vitamin D supplements makes sense for your unique situation.
— Last updated on March 9, 2024 at 9:27 PM