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Head-to-head evidence comparison — which supplement is right for you?
Calcium wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
18 of 20 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
13 of 14 studies with measurable effects showed benefit.
Top outcomes
1000–1200mg daily (split doses)
Split doses with meals, 500mg with breakfast, 500mg with dinner
Calcium Citrate
500-1000mg
With meals containing fat, Split into 2 doses
Quercetin phytosome (improved absorption)
6-24 months
12-36 months
Throughout pregnancy
Within days of starting
2-4 weeks
2-4 weeks
4-8 weeks
Effects of combined calcium and vitamin D supplementation on osteoporosis in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials.
Food & Function (2020) · Meta analysis · n=12000
Combined calcium and vitamin D significantly improved lumbar spine BMD in postmenopausal women
Association Between Calcium or Vitamin D Supplementation and Fracture Incidence in Community-Dwelling Older Adults: A Systematic Review and Meta-analysis.
JAMA (2017) · Meta analysis · n=51145
33 trials involving 51,145 participants were analyzed
Vitamin D and Calcium for the Prevention of Fracture: A Systematic Review and Meta-analysis.
JAMA Network Open (2019) · Meta analysis · n=51419
Meta-analysis of 11 randomized clinical trials with 51,419 participants
Quercetin as a therapeutic agent for skin problems: a systematic review and meta-analysis on antioxidant effects, oxidative stress, inflammation, wound healing, hyperpigmentation, aging, and skin cancer
Naunyn-Schmiedeberg's archives of pharmacology (2025) · Meta analysis · n=1398
Furthermore, quercetin significantly inhibited tyrosinase activity (Z-score, 1.95), resulting in a significantly reduced melanin content (Z-score, 2.56).
Efficacy and safety of dietary polyphenol supplements for COPD: a systematic review and meta-analysis
Frontiers in immunology (2025) · Meta analysis · n=894
This systematic review confirms that the efficacy of dietary polyphenols is significantly composition-specific.
Safety and efficacy of antioxidant therapy in children and adolescents with attention deficit hyperactivity disorder: A systematic review and network meta-analysis
PloS one (2024) · Meta analysis · n=3650
The rankings of safety and efficacy of the 12 antioxidants vary.
Based on meta-analysis of 59 RCTs showing 0.6-1.8% BMD increases. Requires vitamin D co-supplementation for optimal effect. Effectiveness plateaus beyond 1200mg daily.
Meta-analysis of 896 subjects showed modest reductions in systolic (-3.09 mmHg) and diastolic (-2.86 mmHg) BP. Effect size is small and bioavailability varies significantly by form.
AI-estimated from published studies. Interpret as directional guidance.
Calcium has a higher evidence score (8/10 vs 6/10) and wins in 2 of 3 categories.
For bone health, Calcium has a higher relevance score (95 vs 70).
No known interactions between Calcium and Quercetin have been documented in our database. However, always consult a healthcare provider before combining supplements.