21st Century Calcium Plus D3 Tablets
- Calcium
- Tablet
- Calcium, Vitamin D3
- 90
A no-frills calcium and vitamin D3 tablet at 1000mg and 800 IU respectively, built for general bone health support rather than any specialized formula.
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How it ranks among the 107 calcium we track
4.6★ across 1,000 Amazon ratings, Bayesian-smoothed toward the category average.
1,000 Amazon ratings, weighted on a log scale so huge counts don't drown everything.
1,000+ bought on Amazon last month.
Brand identity, imagery, description and spec coverage.
The ProductDome score is separate from the Amazon rating shown above: it combines the Bayesian-smoothed Amazon rating with evidence volume, tracked demand, and data quality across the 107 calcium we track - how the scorecard works · full calcium data report. Confidence: high - strong rating volume and complete data.Last refreshed Aug 4, 2026. Data-computed, not a hands-on test. Compiled by the ProductDome Research Team.
Overview
21st Century combines 1000mg of calcium with 20mcg, or 800 IU, of vitamin D3 in a 90 count tablet, aimed at bone health support for men and women. The formula is gluten free and Non-GMO with no added yeast or artificial flavors.
Pairing calcium with vitamin D3 in one tablet reflects how the body actually uses the mineral, since D3 supports calcium absorption rather than working independently of it. The 800 IU of D3 sits within commonly used daily ranges, though total needs vary by age, diet and sun exposure. At 90 tablets, a full bottle covers a shorter stretch than some 180 or 250 count competitors if taken daily.
- 1000mg calcium per serving
- 800 IU vitamin D3
- 90 tablets
- Bone health positioning
Who it's for
Suited to adults looking for a straightforward calcium and D3 combination for bone health rather than a full multivitamin. Not the right fit for anyone who already gets calcium from a multivitamin and only needs to add vitamin D separately.
Strengths and trade-offs
Drawn from this product's published specifications.
- Calcium paired with D3 for absorption
- Gluten free, Non-GMO formula
- No added yeast or artificial flavors
- 90 count is a shorter supply than larger bottles
- Tablet form, not a capsule or chew
- No added magnesium or vitamin K, which some bone formulas include
Performance notes
Vitamin D3 helps the body absorb calcium from the digestive tract, which is why the two are frequently combined rather than sold as separate single-ingredient supplements. At 1000mg calcium and 800 IU D3, the tablet sits at commonly used daily support levels for bone maintenance. Consistent daily use matters here since calcium and vitamin D support bone density over months, not from a single dose.
Specifications
| Brand | 21st |
|---|---|
| Model | 27070 |
| Form | Tablet |
| Supplement Type | Calcium, Vitamin D3 |
| Count | 90 |
| Benefits | Bone Strength |
| Flavor | Unflavored |
| Diet | Gluten Free |
| Allergens | Gluten Free |
Other 21st calcium
How it compares
This product against the closest alternatives we track in calcium.
| Product | Amazon rating | Ratings | ProductDome score |
|---|---|---|---|
| 21st Century Calcium Plus D3 TabletsThis product | 4.6 / 5 | 1,000 | 4.3 / 5 |
| Nature Made Calcium Magnesium Zinc with Vitamin D3NATURE | 4.8 / 5 | 19,900 | 4.7 / 5 |
| Nature's Bounty Calcium Magnesium & Zinc CapletsNature's | 4.7 / 5 | 23,000 | 4.6 / 5 |
| Caltrate 600 Plus D3 Calcium and Vitamin D Supplement TabletsCaltrate | 4.7 / 5 | 16,400 | 4.6 / 5 |
| Citracal Slow Release- Calcium 1200 mg with Vitamin D3Citracal | 4.7 / 5 | 11,909 | 4.6 / 5 |
Similar calcium from other brands
Questions about the 21st 27070
Common buyer questions answered straight from the product spec data - no fluff, no "it depends".
How much vitamin D3 is in 21st Century 27070?
Each serving provides 20mcg, or 800 IU, of vitamin D3 alongside 1000mg calcium.
Is this calcium supplement gluten free?
Yes, it's labeled gluten free and Non-GMO.
How many tablets come in the bottle?
The bottle contains 90 tablets.