Calcium Carbonate Schedule (India)

Not scheduled (OTC)

Calcium Carbonate Routes

Oral

Calcium Carbonate Formulations

Tablets: 250 mg, 500 mg, 600 mg, 750 mg, 1000 mg (elemental calcium equivalents)

Chewable tablets: 250 mg, 500 mg, 750 mg, 1000 mg

Effervescent tablets: 500 mg, 1000 mg

Oral suspension: 250 mg/5 mL, 500 mg/5 mL

Sachets: Combination products with Vitamin D3 (commonly 500–1000 mg calcium + 400–1000 IU Vitamin D3)

Calcium Carbonate Adult indications

INDICATIONS + DOSING — FOR CLINICIAN USE ONLY

Primary Indications (Approved / Standard in India)

Calcium Supplementation in Deficiency States (Hypocalcaemia, Osteomalacia, Osteoporosis Prevention/Treatment)

ADULTS:

Parameter Recommendation

Starting dose 500–600 mg elemental calcium once or twice daily

Titration Increase by 500 mg increments based on serum calcium and clinical response

Usual maintenance dose 1000–1200 mg/day elemental calcium in divided doses

Maximum dose 2000 mg/day elemental calcium (unless otherwise directed by specialist)

Clinical Notes:

Best absorbed when given in doses ≤500 mg at a time

Administer with meals for optimal absorption (acid-dependent solubility)

Divide doses if total daily requirement exceeds 500 mg

Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD) — Hyperphosphatemia (as Phosphate Binder)

ADULTS:

Parameter Recommendation

Starting dose 1000–1500 mg elemental calcium/day in 2–3 divided doses with meals

Titration Increase by 500 mg increments based on serum phosphate levels

Usual maintenance dose 1500–3000 mg/day in divided doses with meals

Maximum dose Total elemental calcium from diet + supplements should not exceed 2500 mg/day

Clinical Notes:

Monitor calcium × phosphate product regularly (target <55 mg²/dL²)

Considered second-line in many Indian nephrology protocols

Sevelamer preferred if hypercalcaemia present or at risk

Concurrent monitoring of serum calcium, phosphate, and PTH mandatory

Secondary Indications – Adults (Off-label)

Indication Dose Duration Specialist Only Evidence Basis

Dyspepsia (as antacid) — OFF-LABEL 500–1000 mg orally, up to 3–4 times/day as needed Short-term relief only (≤2 weeks) No Traditional use; widespread OTC practice in India

Calcium Carbonate Paediatric indications

PAEDIATRIC DOSING (Specialist Only)

Primary Indication 1: Calcium Supplementation in Deficiency States

Age-based Daily Requirement (Elemental Calcium):

Age Group	Dose (mcg/kg/day)	Typical Total Daily Dose	Clinical Notes

Infant <6months 200 mg/day Not Applicable 200 mg/day 200 mg/day

6-12 months 260 mg/day Not applicable 260 mg/day 260 mg/day

1-3 years 350 mg/day Increase based on clinical need 700 mg/day 700 mg/day

4-8 years 500 mg/day Increase based on clinical need 1000 mg/day 1000 mg/day

9-18 years 650 mg/day Increase based on clinical need 1300 mg/day 1300 mg/day

Clinical Notes:

Divide total dose into 2–3 doses; administer with food for optimal absorption

Use oral suspension or chewable tablets depending on age and swallowing ability

Monitor for GI symptoms and hypercalcaemia with higher doses

Primary Indication 2: Rickets / Vitamin D-Resistant Rickets (Combined with Vitamin D)

PAEDIATRIC:

Parameter Recommendation

Starting dose 50 mg/kg/day elemental calcium in divided doses

Titration Increase to 75 mg/kg/day based on serum calcium and phosphate

Usual maintenance dose 50–75 mg/kg/day in divided doses

Maximum dose 75 mg/kg/day (specialist guidance required)

Clinical Notes:

Specialist management mandatory

Monitor serum calcium, phosphate, alkaline phosphatase, and PTH levels

Secondary Indications – Paediatrics (Off-label)

Indication Dose Duration Specialist Only Evidence Basis

Phosphate binding in paediatric CKD-MBD — OFF-LABEL 30–50 mg elemental calcium/kg/day in divided doses with meals As per nephrologist guidance Yes — Paediatric nephrology mandatory Indian paediatric nephrology protocols

⚠️ Not recommended below 6 months of age except under specialist supervision.

Calcium Carbonate Renal Adjustments

eGFR (ml/min/1.73m²)	Recommendation
eGFR (ml/min/1.73m²)	Recommendation
eGFR (ml/min/1.73m²)	Recommendation
eGFR (ml/min/1.73m²)	Recommendation
Haemodialysis	Monitor calcium closely; adjust dose based on serum levels and phosphate control
Peritoneal dialysis	Same as haemodialysis; individualize based on biochemistry

Calcium Carbonate Hepatic adjustment

Severity	Recommendation
Mild impairment (Child-Pugh A)	No dose adjustment required
Moderate impairment (Child-Pugh B)	No dose adjustment required
Severe impairment (Child-Pugh C)	No dose adjustment required

Calcium Carbonate Contraindications

Hypercalcaemia

Hypercalciuria or nephrolithiasis (calcium-containing stones)

Severe renal failure with uncontrolled calcium-phosphate imbalance

Hypersensitivity to calcium salts or formulation excipients

Elevated calcium × phosphate product (>55 mg²/dL²)

Calcium Carbonate Cautions

History of calcium-containing kidney stones

Concurrent high-dose vitamin D therapy (increased hypercalcaemia risk)

Sarcoidosis or other granulomatous diseases (enhanced calcium absorption)

Cardiac arrhythmias (monitor if hypercalcaemia develops)

Achlorhydria or hypochlorhydria — absorption reduced; consider soluble calcium salts (citrate) in elderly or chronic PPI users

Concurrent digoxin therapy — hypercalcaemia potentiates toxicity

Immobilized patients (increased risk of hypercalcaemia)

Calcium Carbonate Pregnancy

Parameter Recommendation

Overall safety Considered safe throughout pregnancy when used within RDA limits

Preferred alternatives No specific alternative needed; calcium carbonate is first-line for supplementation

When to use Prevention/treatment of pregnancy-associated osteomalacia or hypocalcaemia; routine supplementation in second and third trimesters

Monitoring Serum calcium with higher doses; especially if co-administered with Vitamin D

Calcium Carbonate Lactation

Parameter Recommendation

Breastfeeding compatibility Compatible at nutritional supplementation doses

Preferred alternatives None needed; calcium carbonate is acceptable

Expected drug levels in milk Low (physiological regulation of calcium in milk)

Infant monitoring Rare: monitor for signs of hypercalcaemia (vomiting, poor feeding, constipation)

Calcium Carbonate Elderly

Parameter Recommendation

Starting dose 500 mg elemental calcium/day

Titration Increase gradually based on serum calcium and clinical need

Extra risks Constipation; poor absorption due to achlorhydria; vascular calcification risk with high-dose use in CKD

Clinical note Use chewable or effervescent forms in those with low gastric acid or difficulty swallowing; calcium citrate may be preferred in chronic PPI users

Calcium Carbonate Major drug interactions

Interacting Drug Mechanism/Effect Recommendation

Oral bisphosphonates (alendronate, risedronate) Reduced bisphosphonate absorption Separate by at least 30–60 minutes; take bisphosphonate first on empty stomach

Tetracyclines (doxycycline, minocycline) Chelation → reduced antibiotic absorption Separate by at least 2 hours

Fluoroquinolones (ciprofloxacin, levofloxacin) Chelation → reduced antibiotic absorption Separate by at least 2 hours (preferably 4 hours)

Levothyroxine Reduced absorption → therapeutic failure Separate by at least 4 hours

Thiazide diuretics Increased calcium reabsorption → hypercalcaemia risk Monitor serum calcium; reduce calcium dose if needed

Iron supplements Reduced iron absorption Separate by 2–4 hours

Calcium Carbonate Moderate drug interactions

Interacting Drug Effect Recommendation

PPIs, H2 blockers Reduced calcium carbonate absorption (requires acidic environment) Take with meals; consider calcium citrate in chronic PPI users

Digoxin Hypercalcaemia increases digoxin toxicity risk Monitor serum calcium and digoxin levels

Glucocorticoids Long-term use decreases calcium absorption Calcium supplementation often needed; monitor

Phenytoin Reduced calcium absorption; calcium may reduce phenytoin absorption Separate doses; monitor phenytoin levels

Isoniazid Reduced isoniazid absorption Separate by at least 2 hours

Calcium Carbonate Common Adverse effects

Constipation (most common)

Bloating and flatulence

Chalky taste

Nausea (at high doses)

Belching (especially with effervescent formulations)

Calcium Carbonate Serious Adverse effects

Hypercalcaemia — especially with concurrent high-dose vitamin D; presents as confusion, polyuria, nausea, cardiac arrhythmias

Nephrolithiasis (calcium oxalate stones) — especially if fluid intake is inadequate

Milk-alkali syndrome — rare; occurs with high calcium doses + alkali intake; presents as hypercalcaemia, metabolic alkalosis, and renal impairment

⚠️ Serious hypercalcaemia requires immediate discontinuation and supportive management.

Calcium Carbonate Monitoring requirements

Phase Parameters

Baseline Serum calcium, phosphate, renal function (if risk factors present); dietary calcium intake assessment

During therapy (CKD patients) Serum calcium, phosphate, and PTH every 4–12 weeks; calcium × phosphate product

Long-term use Periodic serum calcium and renal function; assess for signs of hypercalcaemia (polyuria, constipation, confusion)

Calcium Carbonate Brands in India

Shelcal

Ostocalcium

Calcirol-C

Calcium Sandoz

Brand Name	Composition	Manufacturer
*	CCM (Calcium Citrate Malate + Calcium Carbonate	blends)

Supracal

Citracal

Common FDCs: Shelcal HD (with Vitamin D3), Shelcal 500, Supracal D3

Calcium Carbonate Price range (INR)

Formulation	Approximate Price (per tablet)
Tablets (500–1000 mg)	₹1–5 per tablet
FDC Sachets (1 g Calcium + 1000 IU D3)	₹10–20 per sachet
Suspension (250–500 mg/5 mL, 200 mL)	₹50–150 per bottle
Chewable tablets (500 mg)	₹2–6 per tablet

Note: Not under NLEM price control when used as supplement

Calcium Carbonate Clinical pearls

Calcium carbonate requires acidic gastric environment for optimal absorption — administer with meals

For elderly or chronic PPI users, calcium citrate or effervescent formulations may be preferred due to better absorption independent of gastric pH

Split doses exceeding 500 mg into two or more times daily for better GI tolerance and absorption

Avoid concurrent administration with antibiotics (tetracyclines, quinolones) and iron — reduced bioavailability

Long-term use in CKD requires meticulous calcium-phosphate balance monitoring; consider sevelamer if hypercalcaemia risk is high

Assess dietary calcium intake before prescribing supplements to avoid excess and hypercalcaemia

Calcium Carbonate Tags

Calcium Carbonate; calcium supplementation; osteoporosis; CKD-MBD; hyperphosphataemia; phosphate binder; pregnancy-safe; paediatric rickets; renal-caution; bone health; OTC

Calcium Carbonate Version

RxIndia v1.0 — 30 Jan 2026

Calcium Carbonate Reference

CDSCO Formulations List

Indian Pharmacopoeia (IP)

AIIMS 2023 Drug Formulary

API Textbook of Medicine

ICMR Guidelines on Nutritional Requirements 2020

Indian Academy of Paediatrics (IAP) Guidelines

Indian Society of Nephrology practice protocols for CKD-MBD

RxIndia

The Drug Registry

Calcium Carbonate