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· 21,574 ratings· $0.13/serving
Calcium Citrate 630 mg — inside the studied 500-1200 mg window
Of 7,033 products scored for Calcium status, 21st Century, Calcium Citrate + D3 Maximum, 120 Tablets ranks #1 with a DoseRank score of 88. 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 Carbonate
Strong evidence · 500 mg (calculated)
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 Citrate at 630 mg lands inside the studied 500-1200 mg window.
Calcium Citrate
Studied window 500-1200 mg · this pick 630 mg
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.
- 7,033 products scored
- Never paid placement
- Evidence level: Strong · 92
- 550 brands
- 18 ingredients
The price“Can I do better than $0.13 a serving?”Value 79
$0.13 per serving — mid price tier for this outcome. Nothing else in this ranking costs less per serving.
Ready?
The #1 pick is $0.13 a serving.21st Century, Calcium Citrate + D3 Maximum, 120 Tablets — in stock at a tracked retailer.
View on iHerbA saved, shareable breakdown: your matched products, dose math, and interaction flags to discuss with a clinician.
Or take the 60-sec quiz →Questions
Frequently asked
21st Century, Calcium Citrate + D3 Maximum, 120 Tablets ranks #1 for Calcium status with a DoseRank score of 88. The score blends clinical strength, evidence, dose fit, trust signals and value across 7,033 products scored for this outcome.