Calcium 1000 mg by 21st Century — Ingredients, Evidence & Safety

🟢 100/100

This product looks safe

No ingredients exceed tolerable upper intake levels
50% of ingredients have research evidence

A Label Compliance Grade

Product Label

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Label Data

1 Tablet(s) Serving Size

90 Servings

Single Vitamin and Mineral Product Type

50% Evidence Coverage

Supplement Facts — Evidence Check

Vitamin D3

20 mcg (100% DV)

✅ 1.3× RDA — within safe limits 📚 604 studies (Tier A: 16, B: 251)

RDA 0.015mg This product: 0.02mg UL 0.1mg

Calcium

1000 mg (77% DV)

Other Ingredients

Gum Acacia Croscarmellose Sodium FD&C Blue #2 Carmine FD&C Yellow #5 FD&C Yellow #6 Magnesium Silicate Magnesium Stearate Polyethylene Glycol Polyvinyl Alcohol Stearic Acid Titanium Dioxide

Label Claims — Verification

❓ Nutrient

❓ All Other

❓ Structure/Function

All Other (99% of products) Structure/Function (85% of products) Nutrient (54% of products) Approved Health (3% of products)

Target Groups

Adult (18 - 50 Years) Gluten Free

Product Information

📋 Directions for Use

Directions: As a calcium supplement, adults take one (1) tablet daily with any meal or as directed by a healthcare provider.

⚠️ Warnings & Precautions

Do not exceed recommended dosage. Stop use and contact a physician if adverse reactions occur. Do not use if product appears to be tampered with or seal is broken.

Warning: Consult a healthcare provider prior to use if pregnant, nursing, on medications, have a medical condition or are planning a medical procedure.

Keep out of reach of children.

🧪 Formulation Notes

Calcium is an important mineral for bone health. Vitamin D3 is added to assist with calcium absorption.

No added yeast or artificial flavors.

Calcium Plus D3 | 20 mcg (800 IU)

One daily calcium Bone health support Vitamin D3 added to assist calcium absorption

Gluten free | Non-GMO

Guaranteed quality Laboratory tested Trusted quality for over 30 years

Additional Information

Individual results may vary.

Store at room temperature.

Product Details

UPC / SKU 7 40985 27070 7

DSLD Entry Date 2025-04-24

Product Type Single Vitamin and Mineral

Form Tablet or Pill

Brand 21st Century

DSLD ID 334868

Data Updated 2026-04-11

Research Evidence

849 Research Sources

56 Avg Quality Score

450 Meta Analysis

152 Rct

137 Systematic Review

73 Clinical Trial

11 Regulatory Source

7 Other

7 Guideline

3 Openfda Safety

2 Cochrane Review

2 Observational

A Phosphate binders for preventing and treating chronic kidney disease-mineral and bone disorder (CKD-MBD)

Meta Analysis The Cochrane database of systematic reviews 2018

PubMed DOI Cochrane

A Calcium supplementation (other than for preventing or treating hypertension) for improving pregnancy and infant outcomes

Meta Analysis The Cochrane database of systematic reviews 2024

PubMed DOI Cochrane

A Calcium supplementation (other than for preventing or treating hypertension) for improving pregnancy and infant outcomes

Meta Analysis The Cochrane database of systematic reviews 2015

PubMed DOI Cochrane

A Vitamin and mineral supplementation for maintaining cognitive function in cognitively healthy people in mid and late life

Meta Analysis The Cochrane database of systematic reviews 2018

PubMed DOI Cochrane

A Calcium supplementation during pregnancy for preventing hypertensive disorders and related problems

Meta Analysis The Cochrane database of systematic reviews 2025

PubMed DOI Cochrane

A Dietary calcium supplementation for preventing colorectal cancer and adenomatous polyps

Systematic Review The Cochrane database of systematic reviews 2008

PubMed DOI Cochrane

A Calcium and vitamin D for increasing bone mineral density in premenopausal women

Systematic Review The Cochrane database of systematic reviews 2023

PubMed DOI Cochrane

A Dietary sodium, sodium-to-potassium ratio, and risk of stroke: A systematic review and nonlinear dose-response meta-analysis

Meta Analysis Clinical nutrition (Edinburgh, Scotland) 2019

PubMed DOI

A The association between circulating magnesium and clinically relevant outcomes in patients with chronic kidney disease: A systematic review and meta-analysis

Meta Analysis Clinical nutrition (Edinburgh, Scotland) 2021

PubMed DOI

A Calcium channel blockers versus other classes of drugs for hypertension

Systematic Review The Cochrane database of systematic reviews 2021

PubMed DOI

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