A new medical study has found that breast cancer patients with low vitamin D levels may experience more pain after surgery and require larger amounts of opioid painkillers during recovery.
The research, published in the journal Regional Anesthesia & Pain Medicine, suggests that checking vitamin D levels before surgery could potentially help improve patient care in the future.
Breast cancer is one of the most common cancers affecting women around the world. Many patients require surgery to remove cancerous tissue, and in some cases this includes a mastectomy, where one entire breast is surgically removed.
Although surgery can save lives, recovery afterward can be physically and emotionally difficult, especially when patients experience significant pain.
Managing pain after surgery is very important because severe pain can slow recovery, reduce movement, increase emotional stress, and lower overall quality of life. Doctors often use opioid drugs such as fentanyl and tramadol to control pain after major surgery.
While these medications can be effective, they also carry risks including nausea, vomiting, dizziness, drowsiness, constipation, confusion, and potential addiction if used for long periods.
Because of these concerns, researchers are constantly searching for ways to reduce postoperative pain and lower the need for opioid medications.
In recent years, scientists have become increasingly interested in vitamin D and its effects beyond bone health. Vitamin D is widely known for helping the body absorb calcium and maintain strong bones, but researchers now believe it also plays a role in the immune system, inflammation, muscle function, and nerve signaling.
Some earlier studies suggested that vitamin D may influence how pain is processed in the body. Low vitamin D levels have also been linked to chronic pain, muscle weakness, fatigue, and inflammatory conditions.
Vitamin D deficiency is very common worldwide, including among people with breast cancer. Limited sunlight exposure, poor diet, chronic illness, obesity, aging, and cancer treatments may all contribute to lower vitamin D levels.
To explore the connection between vitamin D and surgical pain, researchers at Fayoum University Hospital in Egypt carried out a prospective observational study between September 2024 and April 2025.
The study included 184 women with breast cancer who were scheduled to undergo unilateral modified radical mastectomy. Before surgery, the researchers measured each patient’s vitamin D levels.
Half of the women were found to have vitamin D deficiency, defined as vitamin D levels below 30 nanomoles per liter. The other half had levels above 30 nanomoles per liter and were considered vitamin D sufficient.
The two groups were otherwise similar in age and general characteristics. The average age was 44 years in the vitamin D deficient group and 42 years in the vitamin D sufficient group.
Importantly, the doctors and nurses caring for the patients did not know which women had low vitamin D levels. This helped ensure that treatment decisions and pain management remained unbiased.
During surgery, patients received fentanyl to control acute pain. After surgery, all patients were treated according to the hospital’s standard recovery protocol.
They received intravenous paracetamol every eight hours, and they could also control additional tramadol doses themselves by pressing a button connected to a patient-controlled analgesia device.
Researchers recorded pain scores at several time points during the first 24 hours after surgery. They also monitored side effects such as nausea, vomiting, sedation, and length of hospital stay.
The results showed that women with low vitamin D levels experienced significantly more moderate to severe pain after surgery than women with normal vitamin D levels. Overall, patients with vitamin D deficiency were about three times more likely to report moderate to severe postoperative pain.
Interestingly, none of the women in either group reported extremely severe pain. The difference mainly involved moderate pain levels rather than the most extreme forms of pain.
The researchers also found clear differences in opioid use. Patients with vitamin D deficiency required slightly higher doses of fentanyl during surgery. More importantly, they used much larger amounts of tramadol after surgery.
On average, women with low vitamin D used an additional 112 milligrams of tramadol during the recovery period compared to women with sufficient vitamin D levels.
This finding matters because reducing opioid use is an important goal in modern medicine. Opioid drugs can cause uncomfortable side effects and may increase the risk of dependence or addiction when used repeatedly.
The study also found that nausea after surgery was more common among women with low vitamin D levels. Vomiting occurred only in the vitamin D deficient group, although the number of cases was too small to prove a strong statistical difference.
The researchers believe vitamin D’s role in inflammation and immune system regulation may help explain the findings.
Surgery naturally triggers inflammation in the body, which contributes to pain. Since vitamin D appears to help control inflammatory responses, low levels may leave patients more sensitive to pain signals after surgery.
However, the researchers emphasized that the study has important limitations. Because it was observational, it cannot prove that vitamin D deficiency directly caused the increase in pain or opioid use. Other factors may also have influenced the results.
The study was conducted at only one hospital, and researchers did not collect information about several factors that could affect pain, including anxiety, depression, sleep quality, cancer stage, or previous cancer treatments.
The scientists also did not measure inflammatory markers, so they could not directly study the biological mechanisms behind the relationship between vitamin D and pain.
Even with these limitations, the findings are important because vitamin D deficiency is relatively easy to detect and treat. Vitamin D supplements are inexpensive and widely available. The researchers suggest that checking vitamin D levels before surgery may help identify patients who could face more difficult recoveries.
They also suggest that future clinical trials should investigate whether giving vitamin D supplements before breast cancer surgery could reduce pain and lower opioid use afterward.
If you care about nutrition, please read studies about the power of beetroot juice, and the risks of mixing medications with dietary supplements.
For more health information, please see recent studies about how to boost iron intake: natural solutions for anemia, and results showing vitamin K may lower your heart disease risk by a third.
Source: Fayoum University Hospital.
