Low Vitamin D Linked to Increased Post-Surgery Pain

Breast cancer patients with low vitamin D levels may experience more pain and require more opioid medication after surgery. A study of 184 women undergoing mastectomy found that those with vitamin D deficiency were three times more likely to report moderate to severe pain in the 24 hours following their operation. These patients also used significantly more of the opioid painkiller tramadol.

The research, published in *Regional Anesthesia & Pain Medicine*, suggests a potential link between vitamin D status and postoperative pain management. Patients with vitamin D deficiency, defined as levels below 30 nanomoles per liter, also received slightly more fentanyl during surgery. They experienced increased postoperative nausea compared to patients with sufficient vitamin D levels.

Vitamin D is primarily known for its role in bone health. However, growing evidence indicates it may also influence pain perception and processing. This influence could be related to vitamin D's effects on inflammation and the immune system. Both of these systems can impact the body's pain responses.

The prospective observational study was conducted at Fayoum University Hospital in Egypt. It followed patients from September 2024 to April 2025. Half of the participants had vitamin D deficiency, while the other half had sufficient levels. All patients received standard care, and medical staff were unaware of the patients' vitamin D status. This design helped to prevent bias in pain treatment.

Patients with vitamin D deficiency used an average of 112 milligrams more tramadol after surgery. They also received eight micrograms more fentanyl during the procedure. While the study identifies an association, it does not prove that low vitamin D directly causes increased pain or opioid use. Researchers did not measure inflammatory markers or account for other factors like anxiety or cancer stage, which could influence pain.

Despite these limitations, the findings indicate a strong correlation. The researchers suggest that preoperative vitamin D supplementation for breast cancer patients with levels below 30 nanomoles per liter might help modulate postoperative pain. This could potentially reduce the need for opioid painkillers and their associated side effects.