Calcium
Best for
Build stronger bones in growing kids
Likely strong benefit · 807–850 mg/day for 48 weeks · 1 meta-analysis , n=728
49 papers · 12 claims · 87 outcomes scored · 7 positive
Outcomes
What calcium actually does, by outcome
Each row is one outcome with effect size, evidence base, the dose that worked in trials, and time to first effect. Magnitude tiers come from native-unit MCID where available, Cohen's d otherwise.
Children lay down more bone mass during the years that matter most.
Closes the deficiency gap most people don't know they have.
Restores a nutrient the immune system burns through faster during active TB.
Fewer hip, spine, forearm, and other fractures from weakened bones.
Keeps mineral packed tightly into hip, spine, and whole-body bone.
Restores a mineral your muscles, nerves, and bones rely on every second.
Brings down both systolic and diastolic, especially when baseline runs high.
You naturally gravitate toward more fiber, better fats, and less junk.
Your skeleton tips toward building bone faster than it breaks down.
Corrects the urine chemistry imbalances that let crystals form.
Gets you to sufficient levels before delivery.
| Outcome | Effect | Evidence | Dose | Weeks | Rank |
|---|---|---|---|---|---|
| Build stronger bones in growing kids Likely strong benefit | | 2 meta-analyses n=728 Meta-analyzed | 807–850 mg | 48 wk | — |
| Raise vitamin D levels Large effect, needs confirmation | | 2 RCTs n=40 | 500 mg | 8 wk | #2/2 |
| Replenish immune fuel during TB treatment Large effect, needs confirmation | | 2 RCTs n=40 | 500 mg | 8 wk | #2/2 |
| Lower fracture risk in older adults Proven benefit | | 3 meta-analyses n=135k Meta-analyzed | 500–1600 mg | — | #2/3 |
| Build and maintain bone density Likely benefit | | 7 meta-analyses n=6.0k Meta-analyzed | 250–3320 mg | 19–104 wk | #1/9 |
| Raise calcium when blood levels run low Faint early signal | | 1 RCT n=20 | 500–1800 mg | 52 wk | #1/4 |
| Lower your blood pressure Proven but unnoticeable | | 11 meta-analyses n=6.9k Meta-analyzed | 500–2000 mg | 12–104 wk | #8/81 |
| Improve overall diet quality Not enough research | | 1 meta-analysis n=— Meta-analyzed | — | — | — |
| Strengthen bones by favoring buildup Not enough research | | 1 RCT n=— | 1200–1800 mg | 52 wk | — |
| Reduce kidney stone risk Not enough research | | 2 meta-analyses n=— Meta-analyzed | 500–1800 mg | 10–104 wk | — |
| Raise key nutrient levels in pregnancy Not enough research | | 2 meta-analyses n=— Meta-analyzed | 1500 mg | 19–104 wk | — |
| Protect bones while breastfeeding Doesn't appear to help | | 3 meta-analyses n=1.4k Meta-analyzed | 250–3320 mg | 19–104 wk | — |
Recommended Calcium products
Real products that dose Calcium where the research does, in a clean formulation, from brands we've audited. We only list ones we'd stand behind.
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NOW
Calcium Carbonate Pure Powder
Well dosed 600 mg/day A formulaBrand audit 87/100
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NOW
Calcium Citrate Pure Powder
Well dosed 600 mg/day A formulaBrand audit 87/100
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21st Century
600 Calcium Supplement
Well dosed 1,200 mg/day A formulaBrand audit 77/100
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SuperSmart
Calcium D-Glucarate
Well dosed 1,500 mg/day A formulaBrand audit 63/100
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Solaray
Vitamin C Powder 5000 mg
Well dosed 610 mg/day A formulaBrand audit 76/100
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Nutricost
Calcium Ascorbate 1 g
Well dosed 1,000 mg/day A formulaBrand audit 57/100
Chosen for adequate Calcium dosing vs. the studied range, a clean formulation (grade A–C), and independent brand-quality audits. Not sponsored.
Risk profile
Adverse events and known drug interactions
Safety events
Drug interactions
Co-studied with
Supplements that share evidence with calcium
Sources
- 1. Effects of calcium supplementation on bone density in healthy children: meta-analysis of randomised controlled trials. (2006) ↑
- 2. No effects of low and high consumption of dairy products and calcium supplements on body composition and serum lipids in Puerto Rican obese adults. (2011) ↑
- 3. Effect of calcium supplementation on bone resorption in pregnancy and the early postpartum: a randomized controlled trial in Mexican women. (2014) ↑
- 4. Calcium intake and bone mineral density: systematic review and meta-analysis. (2015) ↑
- 5. The effect of calcium supplementation in people under 35 years old: A systematic review and meta-analysis of randomized controlled trials. (2022) ↑
- 6. Effect of calcium supplementation in pregnancy on maternal bone outcomes in women with a low calcium intake. (2010) ↑
- 7. Calcium intake and risk of fracture: systematic review. (2015) ↑
- 8. Association Between Calcium or Vitamin D Supplementation and Fracture Incidence in Community-Dwelling Older Adults: A Systematic Review and Meta-analysis. (2017) ↑
- 9. Effect of Calcium Fortified Foods on Health Outcomes: A Systematic Review and Meta-Analysis. (2021) ↑
- 10. Calcium-enriched foods and bone mass growth in prepubertal girls: a randomized, double-blind, placebo-controlled trial. (1997) ↑
Generated August 14, 2026
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