The short answer · Gastroesophageal reflux or heartburn
Take calcium carbonate for gastroesophageal reflux or heartburn. 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 500-1000 mg window
Of 3,277 products scored for Gastroesophageal reflux or heartburn, 21st Century, Calcium Plus D3, 90 Tablets ranks #1 with a DoseRank score of 86. Calcium Carbonate is the strongest evidence signal for this outcome.
Retailer links may be affiliate links. Rankings and placement are never paid.
The form“Why Calcium Carbonate — not Magnesium Oxide?”Evidence Strong evidence
Calcium Carbonate is the strongest evidence signal for this outcome.
- 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.
- Magnesium Oxide
Moderate evidence · 400 mg
High-elemental-content magnesium form (60% Mg by weight) but poorly absorbed and strongly laxative — typically used as a stool softener, not for systemic magnesium repletion.
The dose“Is the dose actually effective?”Dose fit 90
Calcium Carbonate at 1000 mg lands inside the studied 500-1000 mg window.
Calcium Carbonate
Studied window 500-1000 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.
- 3,277 products scored
- Never paid placement
- Evidence level: Strong · 92
- 327 brands
- 14 ingredients
The price“Can I do better than $0.07 a serving?”Value 77
$0.07 per serving — mid price tier for this outcome. The cheapest ranked pick here is $0.03 per serving.
- 321st Century, Calcium Supplement 600, 400 Tablets (600 mg per Tablet)Score 86 · $0.03/servingiHerb
- 221st Century, 600+D3, Calcium & Vitamin D3 Supplement, 400 TabletsScore 86 · $0.03/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 Gastroesophageal reflux or heartburn with a DoseRank score of 86. The score blends clinical strength, evidence, dose fit, trust signals and value across 3,277 products scored for this outcome.
Keep exploring
Other outcomes
- Abdominal painPain arising from the abdomen or digestive tract.
- BloatingAbdominal fullness or distension.
- ConstipationInfrequent, difficult, or hard bowel movements.
- DiarrheaLoose or frequent stools.
- Dyspepsia or indigestionUpper abdominal discomfort related to digestion.
- Gas or flatulenceExcess intestinal gas symptoms.