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Calcium 500 + D3

4.8
★ ★ ★ ★ ★
(4358 ratings)
Calcium 500 mg
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Score79
A convenient long-supply calcium and D3 tablet with sensible dosing but incomplete calcium-form disclosure.
How scoring works
Quantity:400 Tablet(s) • (400 servings)
Goals:
Bone Health

Score 79

A convenient long-supply calcium and D3 tablet with sensible dosing but incomplete calcium-form disclosure.
How scoring works

Also available as

3 options
90 servings Calcium 500 mg • 90 Tablet(s) • 90 servings $5.49 ($0.06 per serving) 600mg • 75 Tablet(s) servings Calcium 600 mg • 75 Tablet(s) • 75 servings $4.99 ($0.06 per serving) 1000mg • 90 Tablet(s) servings Calcium 1000 mg • 90 Tablet(s) • 90 servings $6.21 ($0.06 per serving)
$10.99($0.02 per serving)
iHerb
$ 10.99
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Analysis

Five hundred milligrams of calcium is a practical amount for one dose and can help close a meaningful dietary gap. Vitamin D3 supports calcium uptake and use.

The oyster-derived source is visible, but the actual calcium salt is not identified. That omission prevents a precise assessment of meal dependence and absorption characteristics.

The large tablet count may suit established users who need a long supply. It does not address magnesium, vitamin K, or the protein matrix that also contributes to bone quality.

Who is it for
  • Adults with a moderate calcium gap
  • Long-term users who want a large supply
  • People seeking calcium plus D3
Best for
  • Focused calcium supplementation
  • Bone mineral intake
  • Long-supply convenience

Pros

  • Meaningful 500 mg amount
  • Includes vitamin D3
  • Large supply
  • Simple active list

Cons

  • Calcium salt is not specified
  • No magnesium
  • No vitamin K
  • Limited pathway breadth

Warnings

  • Calcium can reduce absorption of levothyroxine, bisphosphonates, tetracycline antibiotics, and quinolone antibiotics; follow dose-separation guidance.
  • People with high blood calcium or recurrent calcium-containing kidney stones should account for total calcium intake before use.

Nutrient quality

81 Highest impact

The calcium compound is not identified, so absorption quality cannot be judged confidently. The 500 mg elemental calcium amount is meaningful for supplementation.

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Ingredient transparency

77 High impact

Active ingredients generally have stated amounts and no proprietary blend hides the doses. Missing other ingredients and complete intake directions leave important label details unresolved.

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Customer satisfaction

66 High impact

The supplied average rating is strong and the rating volume provides a useful aggregate signal. No comment-level evidence is provided to assess recurring complaints or confirm how experience matches the intended purpose.

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Value for money

94 Highest impact

The active amount and formula quality support favorable serving value. The supplied formula is not inflated by obvious low-value extras.

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Goals

Bone Health
Bone Health
Impact
Highest effect
A+ Goal FitB- Strength of SupportB CoverageA+ Formula Quality
Calcium · 500 mgVitamin D · 15 mcg

Calcium at 500 mg provides structural material, while vitamin D3 supports its absorption. The pairing is strongly supported for bone maintenance when dietary intake or vitamin D status is inadequate.

an oyster source without a named calcium compound is clearly disclosed, and the 15 mcg vitamin D3 amount provides useful cofactor support. Vitamin K and protein-matrix support are not included, so pathway coverage remains limited.

Study evidence
Calcium Supportive 144 studies
Vitamin D Supportive 202 studies

Ingredients

IngredientAmount per serving
Vitamin D3 (Cholecalciferol)
 15 mcg
Calcium (Oyster)
 500 mg
Gluten Free Adults 18–50
Report overview
Calcium (Oyster) · 500 mg OverallScore72
F Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyA+ Value

The label names oyster as the source but does not disclose a specific calcium compound. The serving amount is well aligned with efficient absorption, and the mineral quantity is clear. Exceptionally low cost is the main strength despite uncertainty about form quality.

View ingredientView products
Loading alternative details
88 Performance

Calcium Hydroxyapatite Caps

NOW
<p>Hydroxyapatite supplies a practical calcium amount with naturally paired phosphorus and clear dosing. The identified calcium source improves form clarity compared with the original, although the remaining label details are still limited.</p>
85 Performance

Cal/Mag 500 mg/250 mg

NaturesPlus
<p>Chelated calcium and magnesium provide a balanced mineral formula with strong form quality. The identified calcium source improves form clarity compared with the original, although the remaining label details are still limited.</p>
82 Performance

Ultra BoneUp

Jarrow Formulas
<p>Calcium, vitamin D3, magnesium, MK-7, silicon, boron, and cartilage collagen cover several bone pathways. The identified calcium source improves form clarity compared with the original, although the remaining label details are still limited. Magnesium oxide is a weakness, and vitamin K2 needs caution with warfarin-type medicines.</p>
84 Budget

600 Calcium Supplement

21st Century
<p>A straightforward 600 mg calcium carbonate tablet provides a focused serving without unrelated actives. No eligible supplied option at this position is strictly cheaper, so it is included as a closest-cost fallback; carbonate works best with food.</p>
85 Budget

Calcium Carbonate

NOW
<p>A pure calcium carbonate powder supplies a substantial dose with simple active disclosure. No eligible supplied option at this position is strictly cheaper, so it is included as a closest-cost fallback; carbonate works best with food.</p>
84 Budget

Calcium 600 with Vitamin D3

Nature's Bounty
<p>Calcium carbonate and vitamin D3 provide a direct bone-support pairing in a focused formula. No eligible supplied option at this position is strictly cheaper, so it is included as a closest-cost fallback; carbonate works best with food.</p>
88 Value

Calcium Citrate Pure Powder

NOW
<p>Calcium citrate powder provides a substantial, well-absorbed dose with flexible use and strong serving value. The identified calcium source improves form clarity compared with the original, although the remaining label details are still limited. It does not include vitamin D, vitamin K, or magnesium.</p>
82 Value

Calcium Citrate

Nature's Way
<p>Citrate and malate improve absorption flexibility within a practical mixed-calcium serving at strong value. The identified calcium source improves form clarity compared with the original, although the remaining label details are still limited.</p>
85 Value

600+D3

21st Century
<p>A reasonably sized calcium carbonate serving with vitamin D3 provides focused bone support at very low routine cost. The identified calcium source improves form clarity compared with the original, although the remaining label details are still limited. Calcium should be separated from levothyroxine and tetracycline or quinolone antibiotics.</p>
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Sources

Published studies used for the product analysis and the top-ranked studies for each ingredient and goal.

  1. What is the impact of daily oral supplementation of vitamin D3 (cholecalciferol) plus calcium on the incidence of hip fracture in older people? A systematic review and meta-analysis.
    Manoj P; Derwin R; George S · International journal of older people nursing · 2023
    Meta-analysis12,620 participants7 studies pooledBone Health forCalcium
  2. Calcium supplementation prevents seasonal bone loss and changes in biochemical markers of bone turnover in elderly New England women: a randomized placebo-controlled trial.
    Storm D; Eslin R; Porter ES; Musgrave K; Vereault D; Patton C; Kessenich C; Mohan S; Chen T; Holick MF; Rosen CJ · The Journal of clinical endocrinology and metabolism · 1998
    Randomized trial60 participantsBone Health forCalcium
  3. The effects of calcium supplementation (milk powder or tablets) and exercise on bone density in postmenopausal women.
    Prince R; Devine A; Dick I; Criddle A; Kerr D; Kent N; Price R; Randell A · Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research · 1995
    Randomized trial168 participantsBone Health forCalcium
  4. The efficacy of calcium supplementation alone in elderly Thai women over a 2-year period: a randomized controlled trial.
    Rajatanavin R; Chailurkit L; Saetung S; Thakkinstian A; Nimitphong H · Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · 2014
    Randomized trial404 participantsBone Health forCalcium
  5. Calcium-enriched foods and bone mass growth in prepubertal girls: a randomized, double-blind, placebo-controlled trial.
    Bonjour JP; Carrie AL; Ferrari S; Clavien H; Slosman D; Theintz G; Rizzoli R · The Journal of clinical investigation · 1997
    Randomized trial149 participantsBone Health forCalcium
  6. Pregnancy vitamin D supplementation and offspring bone mineral density in childhood follow-up of a randomized controlled trial.
    Moon RJ; D' Angelo S; Curtis EM; Ward KA; Crozier SR; Schoenmakers I; Javaid MK; Bishop NJ; Godfrey KM; Cooper C; Harvey NC; MAVIDOS Trial Group · The American journal of clinical nutrition · 2024
    Randomized trial454 participantsBone Health forVitamin D
  7. Vitamin D analogs and bone: preclinical and clinical studies with eldecalcitol.
    Matsumoto T; Takano T; Saito H; Takahashi F · BoneKEy reports · 2014
    Narrative reviewBone Health forVitamin D
  8. Efficacy of vitamin D fortified foods on bone mineral density and serum bone biomarkers: A systematic review and meta-analysis of interventional studies.
    Tangestani H; Djafarian K; Emamat H; Arabzadegan N; Shab-Bidar S · Critical reviews in food science and nutrition · 2020
    Meta-analysis1,786 participants20 studies pooledBone Health forVitamin D
  9. Cholecalciferol Supplementation Attenuates Bone Loss in Incident Kidney Transplant Recipients: A Prespecified Secondary Endpoint Analysis of a Randomized Controlled Trial.
    Tsujita M; Doi Y; Obi Y; Hamano T; Tomosugi T; Futamura K; Okada M; Hiramitsu T; Goto N; Isaka Y; Takeda A; Narumi S; Watarai Y · Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research · 2022
    Randomized trial193 participantsBone Health forVitamin D
  10. Vitamin D supplementation and bone health in post-menopausal women: a 24-month randomized controlled intervention with enhanced bioavailability formulations.
    Rasool N; Munir Y · European journal of clinical nutrition · 2026
    Randomized trial612 participantsBone Health forVitamin D