Research
Mixed
Daily supplementation with 1000 mg elemental calcium and 400 IU vitamin D3 does not reduce the incidence of invasive breast cancer in postmenopausal women.
For postmenopausal women, taking 1000 mg of calcium and 400 IU of vitamin D3 daily will not reduce the risk of developing invasive breast cancer. While these supplements are important for bone health, they should not be used as a strategy for breast cancer prevention.
StrongRefutesHIGH confidence
Calcium and vitamin D supplementation did not reduce invasive breast cancer incidence in postmenopausal women.
Why this rating
Large-scale, randomized, double-blind, placebo-controlled clinical trial (N=36,282) with long follow-up (mean 7 years).
Source
Calcium Plus Vitamin D Supplementation and the Risk of Breast Cancer
Rowan T. Chlebowski et al. · JNCI Journal of the National Cancer Institute · 2008
DOI 10.1093/jnci/djn360
rct · n=36282Cited 424×
Read the paper DOI resolved against Crossref · corpus check 2026-06-10
More from this paper
Related findings · Mixed
- Bariatric surgery (VSG and RYGB) is the most effective and sustainable treatment for obesity, producing marked and sustained weight loss that non-surgical interventions cannot match.Strong
- Severely protein-deficient diets (2–3% energy) induce lean body mass loss and metabolic imbalance, whereas adequate protein intake (0.66 g/kg/d minimum) is a prerequisite for maintaining muscle, bone, and physiological function.Strong
- For patients with Class III obesity (BMI >39.9 kg/m2), metabolic bariatric surgery (MBS) is significantly more effective than any currently approved medication, with BilioPancreatic Diversion (BPD) showing the highest estimated weight loss.Strong
This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →