SuppHelper
search
Home›Supplements›Mineral›Calcium›Calcium 500+D3 21st Century
Product Image

Calcium 500+D3

21st Century
4.8
★ ★ ★ ★ ★
(10464 ratings)
Product Image
Score 75

An oyster shell calcium supplement providing 500 mg of calcium with Vitamin D3, offering a balanced approach to bone and nail health.

How scoring works
scaleQuantity:90 Tablet(s) • (90 servings)
track_changesGoals:

leaderboard Score 75

An oyster shell calcium supplement providing 500 mg of calcium with Vitamin D3, offering a balanced approach to bone and nail health.

How scoring works
Also available as 3 options
400 servings 1 Tablet(s) • 400 Tablet(s) • 400 servings $6.72 ($0.01 per serving) 400 servings 1 Tablet(s) • 400 Tablet(s) • 400 servings $10.99 ($0.02 per serving) 90 servings 1 Tablet(s) • 90 Tablet(s) • 90 servings $5.49 ($0.06 per serving)
$5.49($0.06 per serving)
iHerb
$ 5.49
iHerb
$ 5.49
flagReport prices
psychologyAnalysis

21st Century Calcium 500+D3 uses oyster shell as its calcium source, which is primarily calcium carbonate. The inclusion of Vitamin D3 is key, as Vitamin D helps facilitate the body's uptake and utilization of calcium, crucial for maintaining strong bones and teeth.

This supplement is suitable for individuals looking for a moderate dose of calcium combined with the important co-factor Vitamin D3. It can help bridge dietary gaps for those needing to increase their calcium and Vitamin D intake without taking excessively high doses at once.

thumb_upPros
  • Provides 500 mg of calcium per serving, a common and manageable dose.
  • Includes Vitamin D3 (5 mcg) to assist with calcium absorption.
  • Oyster shell calcium is a natural source of calcium carbonate.
  • Affordable price per serving.
thumb_downCons
  • Oyster shell calcium is primarily calcium carbonate, which may require sufficient stomach acid for absorption.
  • The Vitamin D3 dose (5 mcg) is on the lower side compared to some alternatives.
  • Tablet form might be large for some individuals.
warningWarnings
  • Oyster shell calcium can sometimes contain trace amounts of heavy metals; however, specific testing information is not provided here.
  • Take with food for potentially better absorption, especially for calcium carbonate.
  • Consult a professional if you have allergies to shellfish, although processing often removes allergenic proteins.
scienceNutrient quality
75 High impact

The inclusion of Vitamin D3 alongside oyster shell calcium is a good choice for supporting absorption and utilization. While 500mg is a moderate dose, the combination is beneficial.

visibilityIngredient transparency
90 Highest impact

The product clearly lists Calcium (from oyster) and Vitamin D3 with their respective quantities. This clarity allows consumers to easily understand the supplement's composition.

workspace_premiumValue for money
85 Highest impact

This product offers excellent value for money, combining a reasonable dose of calcium and Vitamin D3 at a very low price per serving. It's a practical option for daily supplementation.

thumb_upCustomer satisfaction
85 Highest impact

With over 10,402 reviews, this product demonstrates very high customer satisfaction. The large number of positive customer experiences suggests reliability and effectiveness for many users.

storefrontBrand
65 High impact

21st Century is recognized for its value-oriented supplements, making it an accessible brand. They provide foundational products for many health needs.

flagReport analysis
track_changesGoals
flagBone Health
Impact
High effect
The combination of 500 mg of calcium and Vitamin D3 offers good support for bone density and maintenance. Vitamin D3 is crucial for optimizing calcium's benefits for bones.
View goal →
flagNail Health
Impact
High effect
Providing a good dose of calcium with supportive Vitamin D3, this product can contribute to the structural integrity and health of nails. Consistent calcium intake is beneficial for nail strength.
View goal →
scienceIngredients
IngredientAmount per serving
Vitamin D3
5 mcg
Calcium
500 mg
grain_off Gluten Free person Adults 18–50
flagReport overview
Calcium 78
This product is a solid option within the calcium collection, offering a well-regarded form of calcium (oyster shell) paired with essential Vitamin D3. It meets the criteria for effective calcium supplementation.
scienceView ingredientinventory_2View products
inventory_2Alternative products
88 Value

Calcium 500 mg with Vitamin D3

Nature's Bounty
4.8
★★★★★
(1238 ratings)
This option offers a significantly higher analysis score for the same price per serving, providing a robust blend of calcium (from oyster shell) and Vitamin D3 to effectively support your bone and nail health goals.
Other sellers (1)
82 Value

Calcium 600 with Vitamin D3

Nature's Bounty
4.7
★★★★★
(1070 ratings)
For the same price per serving, this product provides a slightly higher dose of calcium (calcium carbonate) and a more robust dose of Vitamin D3, offering enhanced support for bone and nail health.
Other sellers (1)
85 Value

Calcium + Vitamin D

Swisse Ultiboost
4.6
★★★★★
(1270 ratings)
While a bit higher in cost per serving, this product features a good mix of calcium carbonate and calcium citrate with a strong dose of Vitamin D, offering a more comprehensive and highly rated approach to bone and nail support.
Other sellers (0)
88 Performance

Bone Builder Extra Strength

Metagenics
4.8
★★★★★
(81 ratings)
This product features Microcrystalline Hydroxyapatite Concentrate (MCHC), a comprehensive source of calcium and phosphorus in a natural bone matrix, offering superior support for bone density and nail integrity.
Other sellers (1)
88 Performance

Bone Solid

Country Life
4.6
★★★★★
(759 ratings)
This advanced bone health formula includes multiple forms of calcium, Vitamin D3, Vitamin K, and a wide spectrum of essential minerals, all designed to synergistically support robust bones and healthy nails.
Other sellers (3)
88 Performance

Bone Restore with Vitamin K2

Life Extension
4.7
★★★★★
(9991 ratings)
This alternative provides highly bioavailable forms of calcium along with Vitamin D3 and Vitamin K2, a crucial combination that helps optimize calcium utilization and its proper placement for strong bones and nails.
Other sellers (4)
70 Budget

Complete Multivitamin Adults 50+

Equate
4.7
★★★★★
(2231 ratings)
This option offers a broader nutritional profile, including calcium and Vitamin D3, at a slightly lower cost per serving, which can be beneficial for overall well-being beyond just bone and nail health.
Other sellers (0)
75 Budget

600+D3

21st Century
4.8
★★★★★
(7377 ratings)
This is an even more economical choice per serving, providing a good dose of calcium carbonate with Vitamin D3, which effectively contributes to bone and nail health if budget is a primary concern.
Other sellers (1)
72 Budget

Complete Multivitamin Adults 50+

Equate
4.8
★★★★★
(2297 ratings)
For a very low cost per serving, this multivitamin provides calcium and a good amount of Vitamin D3, along with many other beneficial nutrients, which offers broad nutritional support.
Other sellers (0)
88 Value

Calcium 500 mg with Vitamin D3

Nature's Bounty
4.8
★★★★★
(1238 ratings)
This option offers a significantly higher analysis score for the same price per serving, providing a robust blend of calcium (from oyster shell) and Vitamin D3 to effectively support your bone and nail health goals.
Other sellers (1)
82 Value

Calcium 600 with Vitamin D3

Nature's Bounty
4.7
★★★★★
(1070 ratings)
For the same price per serving, this product provides a slightly higher dose of calcium (calcium carbonate) and a more robust dose of Vitamin D3, offering enhanced support for bone and nail health.
Other sellers (1)
85 Value

Calcium + Vitamin D

Swisse Ultiboost
4.6
★★★★★
(1270 ratings)
While a bit higher in cost per serving, this product features a good mix of calcium carbonate and calcium citrate with a strong dose of Vitamin D, offering a more comprehensive and highly rated approach to bone and nail support.
Other sellers (0)
88 Performance

Bone Builder Extra Strength

Metagenics
4.8
★★★★★
(81 ratings)
This product features Microcrystalline Hydroxyapatite Concentrate (MCHC), a comprehensive source of calcium and phosphorus in a natural bone matrix, offering superior support for bone density and nail integrity.
Other sellers (1)
88 Performance

Bone Solid

Country Life
4.6
★★★★★
(759 ratings)
This advanced bone health formula includes multiple forms of calcium, Vitamin D3, Vitamin K, and a wide spectrum of essential minerals, all designed to synergistically support robust bones and healthy nails.
Other sellers (3)
88 Performance

Bone Restore with Vitamin K2

Life Extension
4.7
★★★★★
(9991 ratings)
This alternative provides highly bioavailable forms of calcium along with Vitamin D3 and Vitamin K2, a crucial combination that helps optimize calcium utilization and its proper placement for strong bones and nails.
Other sellers (4)
flagReport alternatives

SuppHelper

Compare supplements smarter. Science-backed, user-rated, updated daily.

Explore

  • Compare Supplements
  • Health Goals
  • Stacks

Legal

  • Privacy Policy
  • Terms of Use
  • Medical Disclaimer

Stay in the Loop

Medical disclaimer: Information on SuppHelper is for educational purposes only and is not medical advice. Statements on this site about dietary supplements have not been evaluated by the Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional before using supplements. Read full disclaimer

© 2025 SuppHelper. All rights reserved.