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Calcium 500+D3

4.8
★ ★ ★ ★ ★
(5357 ratings)
Calcium 500 mg
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Score81
A sensible calcium dose and vitamin D3 support everyday bone intake. The undisclosed calcium compound is the key drawback.
How scoring works
Quantity:400 Tablet(s) • (400 servings)
Goals:
Bone Health

Score 81

A sensible calcium dose and vitamin D3 support everyday bone intake. The undisclosed calcium compound is the key drawback.
How scoring works
$6.72($0.01 per serving)
iHerb
$ 10.99
Pure Formulas
$ 6.72
Walmart
$ 14.58
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Analysis

A moderate calcium serving can help close a dietary gap without overwhelming one dose. Vitamin D3 supports calcium use and gives the formula more relevance than calcium alone.

The oyster source does not state the chemical form of calcium, so absorption cannot be judged precisely. Food is a sensible dosing context in case the source is primarily carbonate.

A high tablet count supports a convenient long-term routine for users comfortable with the source. People wanting a fully specified form or broader nutrient coverage should look elsewhere.

Who is it for
  • Adults seeking long-term basic calcium support
  • Users comfortable with oyster-derived calcium
  • People who prefer a simple tablet
Best for
  • Moderate calcium supplementation
  • Routine use with meals
  • Calcium plus modest vitamin D3

Pros

  • Calcium serving is efficiently sized
  • Includes vitamin D3
  • Simple formula supports easy routine use

Cons

  • Exact calcium compound is unknown
  • Vitamin D3 amount is limited
  • No magnesium or vitamin K

Warnings

  • Calcium can reduce levothyroxine absorption, so follow the medication instructions for spacing the doses.
  • Separate calcium from tetracycline or quinolone antibiotics by the interval stated by the prescriber or pharmacist.
  • Supplemental calcium can cause constipation or bloating; dividing intake may improve tolerance when the label permits it.
  • Calcium carbonate generally works best with food and may be less dependable when stomach acid is low or acid-suppressing medicine is used.
  • The oyster-derived source may not fit people who avoid shell-derived ingredients.

Nutrient quality

83 Highest impact

The calcium amount is well sized, and vitamin D3 supports its use. The unspecified oyster-derived calcium form and modest vitamin D3 amount limit formulation confidence.

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Ingredient transparency

75 High impact

Active amounts and serving counts are mostly clear from the supplied label facts. Missing non-active ingredients and complete directions leave practical disclosure gaps.

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Customer satisfaction

73 High impact

The aggregate rating is strong and supported by a very large feedback volume. Specific experience details are missing, so recurring problems and purpose fit remain uncertain.

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Value for money

97 Highest impact

The very low serving cost supports excellent value despite uncertainty about the calcium form. The large supply delivers exceptional serving value.

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Report analysis

Goals

Bone Health
Impact
High effect
A- Goal FitB- Strength of SupportC- CoverageA- Formula Quality
Calcium · 500 mgVitamin D · 5 mcg

Calcium and vitamin D3 provide focused support for skeletal mineralization. The calcium amount is well suited to a single dose.

The oyster source does not identify the exact calcium compound, which limits confidence in absorption. The vitamin D3 amount is modest, and the formula does not address mineral transport or bone-matrix support.

Study evidence
Calcium Supportive 144 studies
Vitamin D Supportive 202 studies

Ingredients

IngredientAmount per serving
Vitamin D3 (Cholecalciferol)
5 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 500 mg serving is well sized for absorption, but the oyster source does not identify the calcium compound. Elemental calcium is clearly stated, while the exact form's bioavailability remains uncertain. Vitamin D3 and an exceptionally low serving cost make it economical despite that disclosure gap.

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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. Bone turnover and the response to alendronate treatment in postmenopausal osteoporosis.
    Gonnelli S; Cepollaro C; Pondrelli C; Martini S; Montagnani A; Monaco R; Gennari C · Calcified tissue international · 1999
    Randomized trial100 participantsBone Health forCalcium
  4. Associations of dietary calcium intake with metabolic syndrome and bone mineral density among the Korean population: KNHANES 2008-2011.
    Kim MK; Chon SJ; Noe EB; Roh YH; Yun BH; Cho S; Choi YS; Lee BS; Seo SK · Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA · 2018
    Cross-sectional study14,705 participantsBone 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. Calcium and osteoporosis.
    Nordin BE · Nutrition (Burbank, Los Angeles County, Calif.) · 1998
    Meta-analysis20 studies pooledBone Health forCalcium
  7. Dietary calcium intake protects women consuming oral contraceptives from spine and hip bone loss.
    Teegarden D; Legowski P; Gunther CW; McCabe GP; Peacock M; Lyle RM · The Journal of clinical endocrinology and metabolism · 2005
    Randomized trial154 participantsBone Health forCalcium
  8. 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
  9. 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
  10. Effect of milk and calcium supplementation on bone density and bone turnover in pregnant Chinese women: a randomized controlled trail.
    Liu Z; Qiu L; Chen YM; Su YX · Archives of gynecology and obstetrics · 2011
    Randomized trial36 participantsBone Health forCalcium
  11. 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
  12. 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
  13. 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
  14. 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
  15. 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
  16. 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
  17. 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
  18. 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
  19. 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
  20. 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