The short answer · Bone mineral density
Take vitamin d3 (cholecalciferol) & calcium carbonate for bone mineral density. This is the one to buy.
21st Century, Calcium Plus D3, 90 Tablets
4.7· 11,111 ratings· $0.07/serving
Calcium Carbonate 1000 mg — inside the studied 500-1200 mg window
Of 6,784 products scored for Bone mineral density, 21st Century, Calcium Plus D3, 90 Tablets ranks #1 with a DoseRank score of 92. Vitamin D3 (Cholecalciferol) and Calcium Carbonate are the strongest evidence signals for this outcome.
Retailer links may be affiliate links. Rankings and placement are never paid.
The form“Why Vitamin D3 (Cholecalciferol) & Calcium Carbonate?”Evidence Strong evidence
Vitamin D3 (Cholecalciferol) and Calcium Carbonate are the strongest evidence signals for this outcome.
- Vitamin D3 (Cholecalciferol)The pick
Strong evidence · 20 mcg
The form made by skin on sun exposure and used in most supplements; converts to active calcitriol and raises serum 25(OH)D more effectively than D2.
- Calcium CarbonateThe pick
Strong evidence · 1000 mg
The cheapest, most concentrated calcium form at 40% elemental; needs stomach acid, so take with food and expect weak uptake on acid-reducing medications.
The dose“Is the dose actually effective?”Dose fit 66
Calcium Carbonate at 1000 mg lands inside the studied 500-1200 mg window.
Calcium Carbonate
Studied window 500-1200 mg · this pick 1000 mg
The ranking“Why should I trust this pick?”Trust 93
Strong trust signals — consistently high marks from verified buyer ratings. Each product gets a DoseRank score blending clinical strength, evidence, dose fit, trust and value. Retailer links may be affiliate links — the scoring model decides placement, never payment from a brand.
- 6,784 products scored
- Never paid placement
- Evidence level: Strong · 88
- 542 brands
- 25 ingredients
The price“Can I do better than $0.07 a serving?”Value 88
$0.07 per serving — low price tier for this outcome. The cheapest ranked pick here is $0.03 per serving.
- 221st Century, 600+D3, Calcium & Vitamin D3 Supplement, 400 TabletsScore 92 · $0.03/servingiHerb
- 621st Century, 600+D3 Plus Minerals, 120 TabletsScore 90 · $0.04/servingiHerb
Why not the absolute cheapest? The DoseRank score also weighs clinical strength, evidence, dose fit and trust — the very cheapest listings rarely hold up everywhere else.
Ready?
The #1 pick is $0.07 a serving.21st Century, Calcium Plus D3, 90 Tablets — in stock at a tracked retailer.
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21st Century, Calcium Plus D3, 90 Tablets ranks #1 for Bone mineral density with a DoseRank score of 92. The score blends clinical strength, evidence, dose fit, trust signals and value across 6,784 products scored for this outcome.
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