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Calcium 500 mg with Vitamin D3

Nature's Bounty
4.8
★ ★ ★ ★ ★
(2502 ratings)
Calcium 500 mg
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Score81

A practical calcium amount and vitamin D3 offer good value, but the oyster-derived compound is not clearly identified.

How scoring works
Quantity:300 Tablet(s) • (300 servings)
Goals:
Bone Health

Score 81

A practical calcium amount and vitamin D3 offer good value, but the oyster-derived compound is not clearly identified.

How scoring works

Also available as

1 option
600.00mg Calcium • 250 servings Calcium 600 mg • 250 Tablet(s) • 250 servings $14.62 ($0.05 per serving)
$14.83($0.04 per serving)
iHerb
$ 14.83
Vitacost
$ 19.13
iHerb
$ 17.40
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Analysis

The calcium amount fits one sitting and vitamin D3 supports its use. A very long supply makes the tablet practical for routine supplementation.

Oyster sourcing does not tell shoppers whether the calcium is carbonate or another compound. Taking it with a meal is prudent because oyster-shell calcium is commonly carbonate-based and depends more on stomach acid.

The source may not suit people with shellfish-related concerns or those avoiding animal-derived ingredients. The formula should fill a dietary gap rather than automatically push total calcium higher.

Who is it for
  • Adults with a moderate calcium gap
  • People comfortable with oyster-derived ingredients
  • Users seeking a long low-cost supply
Best for
  • Routine calcium maintenance
  • Calcium plus vitamin D3 support
  • Low-cost long-term use

Pros

  • Practical calcium amount
  • Vitamin D3 included
  • Very long supply
  • Low serving cost

Cons

  • Exact calcium compound is unclear
  • Animal-derived source
  • Likely works best with food
  • No magnesium or vitamin K

Warnings

  • The oyster-derived source may not suit people with shellfish allergy concerns or specific dietary restrictions.
  • Separate calcium from levothyroxine and certain antibiotics according to medication guidance.
  • Kidney stones, high blood calcium, or significant kidney disease require medical guidance.

Nutrient quality

86 Highest impact

Calcium and vitamin D are sensibly paired in practical amounts. The oyster-derived source is likely carbonate and may depend more on food and stomach acid.

Ingredient transparency

70 High impact

Calcium is clearly quantified, but duplicate vitamin D entries make the label less certain. Intake directions and non-active tablet ingredients are not included in the supplied facts.

Customer satisfaction

73 High impact

The aggregate rating is strong and has a useful response base. No review text is supplied, so repeated complaints and purpose-specific experiences cannot be verified.

Value for money

97 Highest impact

A practical calcium dose and vitamin D are delivered at a very low ongoing cost. The focused formula compares favorably with similar basic products.

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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 · 10 mcg

Calcium and vitamin D3 form a focused combination for bone mineral supply and calcium absorption. The calcium amount fits a practical single dose, while vitamin D3 adds a relevant cofactor.

Oyster-sourced calcium is usually carbonate-based and may depend on food and adequate stomach acid for better absorption. The formula does not cover vitamin K, magnesium, trace-mineral cofactors, or the collagen matrix.

Study evidence
Calcium Supportive 144 studies

Ingredients

IngredientAmount per serving
Vitamin D (Cholecalciferol, Vitamin D3)
 10 mcg
Calcium (Oyster)
 500 mg
Sodium
10 mg
Gluten Free Adults 18–50 Dairy Free Sugar Free
Report overview
Calcium (Oyster) · 500 mg OverallScore86
C+ Active Ingredient Quality & BioavailabilityA+ Dose, Safety & Label TransparencyA+ Value

The serving delivers a practical calcium amount that fits typical per-dose absorption limits. Oyster-sourced calcium is usually carbonate-based, so absorption may depend more on food and stomach acid than with citrate or chelated forms. Vitamin D3 and very low serving cost add practical value.

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Loading alternative details
88 Performance

Calcium Hydroxyapatite Caps

NOW
<p>Hydroxyapatite supplies a practical calcium amount with naturally paired phosphorus and clear dosing. Citrate or chelated forms offer more absorption flexibility than the original carbonate or oyster-derived source.</p>
85 Performance

Cal/Mag 500 mg/250 mg

NaturesPlus
<p>Chelated calcium and magnesium provide a balanced mineral formula with strong form quality. It adds magnesium and other bone cofactors beyond the original calcium-and-vitamin-D pairing.</p>
82 Performance

Ultra BoneUp

Jarrow Formulas
<p>Calcium, vitamin D3, magnesium, MK-7, silicon, boron, and cartilage collagen cover several bone pathways. It adds magnesium and other bone cofactors beyond the original calcium-and-vitamin-D pairing. 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. It lowers routine cost while maintaining direct calcium support, although carbonate still 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. Citrate or chelated forms offer more absorption flexibility than the original carbonate or oyster-derived source. 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. Citrate or chelated forms offer more absorption flexibility than the original carbonate or oyster-derived source.</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. It keeps calcium support economical, although the same food-dependent carbonate limitation remains. 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. Calcium supplementation during pregnancy and maternal and offspring bone health: a systematic review and meta-analysis.
    Tihtonen K; Korhonen P; Isojärvi J; Ojala R; Ashorn U; Ashorn P; Tammela O · Annals of the New York Academy of Sciences · 2022
    Meta-analysis1,566 participants7 studies pooledBone Health forCalcium
  2. Calcium supplementation and bone mineral density in postmenopausal women using estrogen replacement therapy.
    Haines CJ; Chung TK; Leung PC; Hsu SY; Leung DH · Bone · 1995
    Randomized trialBone Health forCalcium
  3. Calcium supplementation provides an extended window of opportunity for bone mass accretion after menarche.
    Rozen GS; Rennert G; Dodiuk-Gad RP; Rennert HS; Ish-Shalom N; Diab G; Raz B; Ish-Shalom S · The American journal of clinical nutrition · 2003
    Randomized trial100 participantsBone Health forCalcium
  4. Relationship between bone mineral density changes and risk of fractures among patients receiving calcium with or without vitamin D supplementation: a meta-regression.
    Rabenda V; Bruyère O; Reginster JY · Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · 2011
    Meta-analysis47,365 participants15 studies pooledBone Health forCalcium
  5. Treatment with alendronate plus calcium, alendronate alone, or calcium alone for postmenopausal low bone mineral density.
    Bonnick S; Broy S; Kaiser F; Teutsch C; Rosenberg E; DeLucca P; Melton M · Current medical research and opinion · 2007
    Randomized trial701 participantsBone Health forCalcium
  6. 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
  7. 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
  8. 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
  9. 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
  10. 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