The short answer · Calcium status
Take calcium citrate & vitamin d3 (cholecalciferol) for calcium status. This is the one to buy.
21st Century, Calcium Citrate + D3 Maximum, 120 Tablets
4.8· 21,504 ratings· $0.13/serving
Calcium Citrate 630 mg — inside the studied 500-1200 mg window
Of 8,124 products scored for Calcium status, 21st Century, Calcium Citrate + D3 Maximum, 120 Tablets ranks #1 with a DoseRank score of 89. Calcium Citrate and Vitamin D3 (Cholecalciferol) are the strongest evidence signals for this outcome.
Retailer links may be affiliate links. Rankings and placement are never paid.
The form“Why Calcium Citrate & Vitamin D3 (Cholecalciferol)?”Evidence Strong evidence
Calcium Citrate and Vitamin D3 (Cholecalciferol) are the strongest evidence signals for this outcome.
- Calcium CitrateThe pick
Strong evidence · 630 mg
Calcium bound to citric acid; absorbed well even without food or with low stomach acid, so it suits older adults and PPI users.
- Vitamin D3 (Cholecalciferol)The pick
Strong evidence · 12.5 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 Hydroxyapatite
Strong evidence · 907 mg
Calcium drawn from bone mineral, supplying calcium and phosphorus in a natural ratio with trace collagen; marketed for bone-density support.
The dose“Is the dose actually effective?”Dose fit 66
1 of 2 dosed ingredients land in the studied range. Calcium Citrate at 630 mg lands inside the studied 500-1200 mg window.
Calcium Citrate
Studied window 500-1200 mg · this pick 630 mg
Vitamin D3 (Cholecalciferol)
Studied window 400-5000 IU · this pick 12.5 mcg
The ranking“Why should I trust this pick?”Trust 95
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.
- 8,124 products scored
- Never paid placement
- Evidence level: Strong · 92
- 588 brands
- 18 ingredients
The price“Can I do better than $0.13 a serving?”Value 80
$0.13 per serving — low price tier for this outcome. The cheapest ranked pick here is $0.13 per serving.
- 3Swanson Vitamins, Calcium Citrate & Vitamin D3, 250 TabletsScore 87 · $0.13/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 $0.13 a serving.21st Century, Calcium Citrate + D3 Maximum, 120 Tablets — in stock at a tracked retailer.
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21st Century, Calcium Citrate + D3 Maximum, 120 Tablets ranks #1 for Calcium status with a DoseRank score of 89. The score blends clinical strength, evidence, dose fit, trust signals and value across 8,124 products scored for this outcome.
Calcium Citrate and Vitamin D3 (Cholecalciferol) are the strongest evidence signals for this outcome.
1 of 2 dosed ingredients land in the studied range. Calcium Citrate at 630 mg lands inside the studied 500-1200 mg window. DoseRank scores this product's dose fit at 66 out of 100.
21st Century, Calcium Citrate + D3 Maximum, 120 Tablets works out at $0.13 per serving. $0.13 per serving — low price tier for this outcome. The cheapest ranked pick here is $0.13 per serving.
No. Retailer links may be affiliate links, but rankings and placement are never paid. Every product is scored by the same public model, and the ranking is recomputed from the underlying product data rather than edited by hand.