08/13/2026
Alliance SOLARIS Trial: Vitamin D3 Fails to Boost Colorectal Cancer Survival
For patients with advanced colorectal cancer, adding high-dose vitamin D3 to standard first-line treatment does not improve progression-free survival, according to the results from the Alliance Phase III SOLARIS trial published in the JAMA.
Key takeaways
• Main result: Patients who received high-dose vitamin D3 had a median progression-free survival of 11.8 months, compared with 10.3 months for those who received standard-dose vitamin D3. This difference was not statistically significant.
• Overall survival and tumor response: Overall survival was also similar between the groups (25.6 months vs. 27.0 months), as were objective response rates (51% vs. 44%). Neither difference was statistically significant.
• Safety and tolerability: High-dose vitamin D3 was generally well tolerated when given with standard treatment. Vitamin D-related complications, such as high blood calcium and kidney stones), were rare, with no significant difference between the treatment groups.
• Vitamin D levels: The high-dose vitamin D3 regimen successfully increased participants' vitamin D blood levels into the target range.
“While we are disappointed that high-dose vitamin D3 did not improve overall outcomes in patients with metastatic colorectal cancer, these definitive findings provide clear guidance for oncology clinicians and patients navigating treatment decisions,” said lead author Kimmie Ng, MD, MPH, Professor of Medicine at Harvard Medical School, Associate Chief of the Division of Gastrointestinal Oncology at Dana-Farber Cancer Institute (DFCI), and the Founding Director of the Young-Onset Colorectal Cancer Center at DFCI.
Read the Alliance news story at: https://bit.ly/SOLARIS-trial
Read the JAMA article at: https://bit.ly/SOLARIS-JAMA