What is the amount of elemental calcium in Caltrate Plus (calcium supplement)?

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Elemental Calcium Content in Caltrate Plus

Caltrate 600™ contains 600 mg of elemental calcium per tablet, which is 40% of the 1,500 mg calcium carbonate content. 1

Understanding Calcium Supplements

  • Calcium supplements are available in various formulations, with calcium carbonate being the most common and cost-effective form, providing 40% elemental calcium by weight 1
  • Calcium citrate provides less elemental calcium (21%) but may be better absorbed when taken without food 1
  • Other forms include calcium lactate (13% elemental calcium) and calcium gluconate (9% elemental calcium), which are less commonly used due to their lower calcium content 1

Caltrate Plus Composition and Dosing

  • Caltrate 600™ contains 1,500 mg of calcium carbonate, which provides 600 mg of elemental calcium per tablet 1
  • To obtain 1,500 mg of elemental calcium (a common therapeutic dose), one would need to take 2.5 tablets of Caltrate 600™ 1
  • Calcium carbonate supplements like Caltrate should be taken with meals to ensure optimal absorption, as gastric acidity improves absorption 1

Optimal Calcium Supplementation Practices

  • The maximum dose of elemental calcium that should be taken at one time is 500 mg to optimize absorption 2
  • If daily supplementation exceeds 500 mg of elemental calcium, divided doses are recommended to improve absorption and minimize gastrointestinal side effects 1
  • Calcium carbonate is more likely to cause constipation and bloating compared to other calcium supplements 1

Clinical Considerations

  • Recommended daily calcium intake varies by age and sex: 1,000 mg for adults 19-50 years and men 51-70 years; 1,200 mg for women over 50 and men over 70 1
  • Upper intake levels should not exceed 2,500 mg per day (2,000 mg per day in persons >50 years of age) 1
  • Calcium from dietary sources (dairy products, leafy greens, fortified foods) is generally preferred over supplements when possible 1

Common Pitfalls

  • Taking calcium supplements simultaneously with bisphosphonates can reduce the absorption of the latter 3
  • Calcium carbonate requires gastric acid for optimal absorption; patients on acid-reducing medications may benefit from calcium citrate instead 1
  • Excessive calcium supplementation (>1,500 mg/day) has been associated with increased risk of advanced prostate cancer 2 and may potentially increase the risk of vascular calcification, particularly in patients with chronic kidney disease 4

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Calcium supplementation in clinical practice: a review of forms, doses, and indications.

Nutrition in clinical practice : official publication of the American Society for Parenteral and Enteral Nutrition, 2007

Research

Calcium supplementation in chronic kidney disease.

Expert opinion on drug safety, 2014

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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