Supplements – OncWonk – Dr Bier's Oncology Research Reviews

Review: the impacts of circulating 25-hydroxyvitamin D levels on cancer patient outcomes: a systematic review and meta-analysis

November 19, 2025

💡 Comment: The Moderate certainty evidence presented in this meta-analysis underscores the profound impact of circulating 25-hydroxyvitamin D [25(OH)D] levels on cancer patient outcomes. Although this analysis is limited to colorectal cancer, breast cancer, and lymphoma, there’s no reason to believe it doesn’t apply across the board. Yes it is based on observational studies and […]

Dietary Supplement Use During Chemotherapy and Survival Outcomes of Patients With Breast Cancer Enrolled in a Cooperative Group Clinical Trial (SWOG S0221)

October 23, 2025

| No Comments

| Antioxidants, Cancer - Breast, Supplements, Vitamin B12

Comment: This article was a source of great concern to patients and oncologists when it first came out, and still is. As published in ASCO:“Using antioxidants and other dietary supplements before and during adjuvant chemotherapy for breast cancer may increase the risk of recurrence and “to a lesser extent, death,” according to an analysis of […]

Effect of Vitamin D2 Supplementation on 25-Hydroxyvitamin D3 Status: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

September 28, 2025

| No Comments

| Vitamin D

Comment I’ve been using a basic rule of thumb – D3 – D2 = real vitamin D This study doesn’t exactly say that, but does give me a basis for my general statement that D2 may be worse than no D at all as it negatively impacts D3 status. Summary Title of the Article: […]