← Issue №5/ week of Aug 2, 2026/Colorectal

Addition of High-Dose Vitamin D3 to Standard Treatment in Patients With Metastatic Colorectal Cancer: The SOLARIS Randomized Clinical Trial (Alliance A021703).

From GI Signals issue №5: what this paper found, what it changes, and where it sits against the current standard of care, reviewed by Simon Mathews, MD.

Colorectal rct · n=455 · Aug 3, 2026 · JAMA · IF 63.1

Addition of High-Dose Vitamin D3 to Standard Treatment in Patients With Metastatic Colorectal Cancer: The SOLARIS Randomized Clinical Trial (Alliance A021703).

New evidencecolorectal cancerbasic sciencebiomarker
Clinical takeawayNo clinical action: high-dose vitamin D3 is not superior to standard-dose in mCRC treatment.
What it foundHigh-dose vitamin D3 (8000 IU loading then 4000 IU daily) did not improve PFS (11.8 vs 10.3 months) or OS (25.6 vs 27.0 months) compared to standard-dose vitamin D3 (400 IU daily) in patients with metastatic colorectal cancer (mCRC) receiving chemotherapy. There were no significant differences in adverse events between the two doses.
ContextChallenges prior phase 2 data suggesting benefit of high-dose vitamin D3 in mCRC; confirms standard-dose remains appropriate.
No standard claimed for this paper

Every paper is compared to the standard governing its question. This one is not: either no standard in the corpus matches it, or the comparison did not hold up on review and was withdrawn rather than published unverified. Both are logged.

Ng K … Meyerhardt JA · JAMA · IF 63.1 · PubMed ↗Permalink
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