Researchers studied 257 cancer patients receiving chemotherapy and compared them to 257 healthy people of similar age and gender. They found that cancer patients have much weaker bones than healthy people, with about 21% developing osteoporosis (very weak bones) compared to only 2% of healthy people. The study also discovered that cancer patients are seven times more likely to develop weak bones. Vitamin D deficiency was common in cancer patients and linked to weaker bones. The good news? A higher body weight actually protected bones somewhat. These findings suggest that doctors should pay special attention to bone health in cancer patients to help them maintain quality of life during and after treatment.

The Quick Take

  • What they studied: Whether cancer patients receiving chemotherapy develop weaker bones compared to people without cancer, and what factors might predict who gets weak bones
  • Who participated: 514 people total—257 cancer patients getting chemotherapy and 257 healthy people matched by age and gender. The average age was 59, with about two-thirds being women and one-third being men
  • Key finding: Cancer patients were 6.8 times more likely to have osteoporosis (very weak bones). About 21% of cancer patients had osteoporosis in their spine compared to only 2% of healthy people. Additionally, 37% of cancer patients had osteopenia (moderately weak bones) versus 16% of healthy people
  • What it means for you: If you’re being treated for cancer with chemotherapy, your bones may become weaker during treatment. This suggests you should talk to your doctor about bone health monitoring and possibly getting vitamin D checked. However, this study shows a connection but doesn’t prove chemotherapy directly causes weak bones in every person

The Research Details

This was a matched comparison study conducted across multiple hospitals. Researchers recruited 257 cancer patients who had received chemotherapy and carefully selected 257 healthy people who were similar in age and gender to create a fair comparison. They used a special statistical method called propensity score matching to make sure the two groups were as similar as possible except for the cancer diagnosis. Both groups had their bone density measured using a standard test called DXA scanning, which takes pictures of bones to see how dense and strong they are. The researchers also collected blood samples to check vitamin D levels and other markers related to bone health.

By matching cancer patients with similar healthy people, researchers could see the true effect of cancer and chemotherapy on bones without other factors getting in the way. This approach is stronger than just comparing any cancer patients to any healthy people, because it controls for age and gender differences that naturally affect bone strength

This study was conducted at multiple hospitals, which makes the results more reliable because they likely apply to different populations. The researchers carefully excluded people taking bone-affecting medications or with other bone diseases, which made the comparison cleaner. However, because this is a cross-sectional study (taking a snapshot in time rather than following people over years), we can see that cancer patients have weaker bones but can’t be completely certain that chemotherapy caused the weakness. The study also excluded people with severe health problems, so results may not apply to the sickest cancer patients

What the Results Show

Cancer patients had significantly weaker bones than healthy people. In the spine (lumbar vertebrae), 21% of cancer patients had osteoporosis compared to only 2.3% of healthy people—that’s about 9 times higher. Additionally, 37% of cancer patients had osteopenia (moderately weak bones) compared to 16.3% of healthy people. When researchers measured actual bone density numbers, cancer patients’ spine bones were 26.2% weaker on average, and hip bones were 9.2% weaker. The overall risk of having osteoporosis was 6.8 times higher in cancer patients, meaning cancer dramatically increased weak bone risk. Different cancer types showed different patterns: breast cancer patients had the most normal bone density overall but also had the highest osteoporosis rate at 31.5%, while gastric cancer patients showed the highest hip bone weakness at 33.3%.

Vitamin D deficiency was much more common in cancer patients (50.6%) than healthy people (18.1%), and low vitamin D was linked to weaker bones. Interestingly, higher body weight appeared protective—for every unit increase in BMI (body mass index), the risk of osteoporosis decreased by 4.5%. Blood tests for kidney function, liver enzymes, calcium, and phosphate levels were similar between groups and didn’t predict who would develop weak bones, suggesting these weren’t the main factors driving bone loss in cancer patients

Previous research has suggested that cancer and its treatments can weaken bones, but this study provides clearer numbers about how much weaker they become. The finding that cancer increases osteoporosis risk nearly 7-fold is more dramatic than some earlier estimates, suggesting the problem may be more serious than previously thought. The strong connection between vitamin D deficiency and weak bones in cancer patients aligns with other research showing vitamin D’s importance for bone health

This study took a snapshot at one point in time rather than following patients over months or years, so we can’t be completely certain that chemotherapy directly caused the bone weakness—other factors related to cancer itself might be responsible. The study excluded people taking certain bone-protecting medications and those with other bone diseases, so results may not apply to all cancer patients. We don’t know how long patients had been receiving chemotherapy or how long ago they finished treatment, which could affect bone density. The study also excluded people with severe organ problems, so results may not apply to the sickest patients

The Bottom Line

If you’re receiving or have received chemotherapy for cancer, ask your doctor about: (1) getting your bone density checked with a DXA scan, (2) having your vitamin D levels tested and supplemented if low, (3) ensuring adequate calcium intake through diet or supplements, and (4) doing weight-bearing exercise if your doctor approves. These steps may help protect your bones during and after cancer treatment. Confidence level: Moderate—the study shows a clear connection, but more research is needed to prove these interventions prevent bone loss in cancer patients

This research is most relevant to cancer patients receiving chemotherapy, their doctors, and cancer care teams. It’s especially important for breast cancer, colorectal cancer, and gastric cancer patients based on this study’s findings. Family members of cancer patients should also be aware, as they can help encourage bone-healthy behaviors. Healthy people without cancer don’t need to change their approach based on this study, though the vitamin D findings may have general relevance

Bone loss from chemotherapy likely develops gradually over months of treatment. You probably won’t notice symptoms immediately, as weak bones often don’t cause pain or obvious signs. It may take several months to a year after starting treatment before bone density changes become measurable on scans. Benefits from protective measures like vitamin D supplementation and exercise may take 6-12 months to show up in bone density tests

Want to Apply This Research?

  • Track vitamin D intake daily (target 1000-2000 IU for cancer patients) and log any bone-related symptoms like bone pain, fractures, or height loss. Also track weight-bearing exercise minutes per week (aim for 150 minutes) to help maintain bone strength
  • Set a daily reminder to take vitamin D supplements if prescribed, log calcium-rich foods at meals (dairy, leafy greens, fortified foods), and schedule weekly weight-bearing exercise like walking or light strength training. Create a reminder for bone density screening appointments recommended by your doctor
  • Use the app to track bone health markers over time: record DXA scan results when available, monitor vitamin D supplement adherence, track exercise consistency, and log any bone-related symptoms or concerns. Set quarterly check-in reminders to review progress with your healthcare team and adjust the plan as needed

This research shows that cancer patients receiving chemotherapy have weaker bones than healthy people, but it doesn’t prove that chemotherapy directly causes all bone loss. If you have cancer or are receiving chemotherapy, talk to your oncologist or doctor before making any changes to your diet, supplements, or exercise routine. This information is not a substitute for medical advice from your healthcare team. Bone health decisions should be personalized based on your specific cancer type, treatment plan, and overall health status. Always consult with your doctor before starting vitamin D supplements, calcium supplements, or new exercise programs, especially during active cancer treatment.