Product Image

Calcium Citrate +D3 Maximum

21st Century
4.8
★ ★ ★ ★ ★
(48873 ratings)
Calcium 630 mg
Product Image
Score84
A strong calcium citrate and D3 option with a useful supply, though the full calcium amount is better considered as divided intake.
How scoring works
Quantity:120 Tablet(s) • (60 servings)
Goals:
Bone Health

Score 84

A strong calcium citrate and D3 option with a useful supply, though the full calcium amount is better considered as divided intake.
How scoring works

Also available as

2 options
400mg • 200 Tablet(s) servings Calcium 400 mg • 200 Tablet(s) • 100 servings $10.99 ($0.10 per serving) 75 servings Calcium 630 mg • 75 Tablet(s) • 37 servings $6.49 ($0.17 per serving)
$8.49($0.14 per serving)
iHerb
$ 8.49
iHerb
$ 8.49
Amazon
$ 8.49
Report prices

Analysis

The citrate form offers dependable absorption without the same reliance on meals or high stomach acid as carbonate. Vitamin D3 complements the mineral by supporting calcium absorption and regulation.

The 630 mg amount can close a sizable dietary gap but may exceed what is used most efficiently at once. A split serving may improve absorption and gastrointestinal comfort.

The larger bottle offers more servings than the otherwise similar smaller package. The active formula remains narrow, with no magnesium, vitamin K2, or structural protein support.

Who is it for
  • Adults seeking calcium citrate
  • Users who want a larger supply
  • People with a substantial calcium shortfall
Best for
  • Bone mineral support
  • Calcium and vitamin D supplementation
  • Citrate-based calcium intake

Pros

  • Uses calcium citrate
  • Includes vitamin D3
  • Clear active amounts
  • Larger supply

Cons

  • Substantial amount may need division
  • Lacks magnesium
  • Lacks vitamin K2
  • Does not support the collagen matrix

Warnings

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

Nutrient quality

89 Highest impact

Calcium citrate is a well-absorbed form that does not depend heavily on stomach acid. The 630 mg serving is slightly above the usual absorption-focused amount and may work better when divided.

.

Ingredient transparency

81 Highest 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.

.

Customer satisfaction

67 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.

.

Value for money

96 Highest impact

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

.
Report analysis

Goals

Bone Health
Bone Health
Impact
Highest effect
A Goal FitA Strength of SupportC+ CoverageA+ Formula Quality
Calcium · 630 mgVitamin D · 13 mcg

Calcium citrate provides a meaningful structural-mineral dose, while vitamin D3 supports its absorption. Both ingredients use appropriate forms and are clearly disclosed.

The focused pairing gives good depth for mineral supply and transport but does not address magnesium, vitamin K2, or the collagen matrix. People prone to calcium kidney stones or high blood calcium should avoid adding this 630 mg supplement without considering total calcium intake.

Study evidence
Calcium Supportive 144 studies
Vitamin D Supportive 202 studies

Ingredients

IngredientAmount per serving
Vitamin D3 (Cholecalciferol)
 13 mcg
Calcium (Calcium Citrate)
 630 mg
Gluten Free Adults 18–50
Report overview
Calcium (Calcium Citrate) · 630 mg OverallScore80
A- Active Ingredient Quality & BioavailabilityC Dose, Safety & Label TransparencyA+ Value

Calcium citrate offers dependable absorption and clear mineral disclosure. The serving is slightly above the preferred single-dose range, making divided intake more efficient. Very low cost supports excellent practical value.

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. It preserves a well-absorbed calcium approach while improving either serving flexibility or practical value over the original.</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 citrate-only approach, with some trade-off in formula simplicity.</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 citrate-only approach, with some trade-off in formula simplicity. 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 costs less per serving, though carbonate is less flexible than the original citrate and works best with food.</p>
85 Budget

Calcium Carbonate

NOW
<p>A pure calcium carbonate powder supplies a substantial dose with simple active disclosure. It costs less per serving, though carbonate is less flexible than the original citrate and 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. It costs less per serving, though carbonate is less flexible than the original citrate and 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. It preserves a well-absorbed calcium approach while improving either serving flexibility or practical value over the original. 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. It preserves a well-absorbed calcium approach while improving either serving flexibility or practical value over the original.</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 improves cost or cofactor coverage, though carbonate is less flexible than the original citrate and works best with food. Calcium should be separated from levothyroxine and tetracycline or quinolone antibiotics.</p>
Report alternatives

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