Is Calcium Acetate Available Over-the-Counter?
Calcium acetate is NOT typically available over-the-counter in the United States; it is primarily available as a prescription medication (brand name PhosLo) used as a phosphate binder in patients with chronic kidney disease. 1
Regulatory Status and Availability
- Calcium acetate is classified as a prescription medication when used as a phosphate binder for hyperphosphatemia management in CKD and dialysis patients 1
- The brand name PhosLo (667 mg calcium acetate containing 167 mg elemental calcium per tablet) requires a prescription 1
- Some combination products containing calcium acetate with magnesium carbonate (such as MagneBind) are also prescription-only 1
Why Calcium Acetate Requires Prescription
- Calcium acetate is specifically indicated for phosphate binding in renal disease, not for general calcium supplementation 1, 2
- The dosing requires careful monitoring of serum calcium, phosphorus, and calcium-phosphorus product to avoid vascular calcification 1, 2
- Total elemental calcium intake from diet and phosphate binders should not exceed 2,000 mg/day due to risks of hypercalcemia and cardiovascular calcification 2
- When used with active vitamin D therapy (calcitriol), calcium acetate markedly increases intestinal calcium absorption, requiring close monitoring 2
OTC Alternatives for Calcium Supplementation
If you need calcium supplementation (not phosphate binding), calcium carbonate products like TUMS are available over-the-counter and are more appropriate:
- TUMS products provide 40% elemental calcium and are widely accepted calcium supplements 3
- Available formulations include TUMS EX (300 mg elemental calcium), TUMS Ultra (400 mg elemental calcium), and TUMS 500 (500 mg elemental calcium) 3
- These should be taken with meals in divided doses of ≤500 mg elemental calcium per dose to maximize absorption 3
Critical Distinction
- Calcium acetate (25% elemental calcium) is used as a phosphate binder taken WITH meals to bind dietary phosphorus in the gut 1, 2
- Calcium carbonate (40% elemental calcium) is used as a calcium supplement and is available OTC 3
- These are not interchangeable products—calcium acetate causes fewer hypercalcemic events than calcium carbonate when used as a phosphate binder 2
Common Pitfall to Avoid
Do not attempt to use OTC calcium carbonate products as a substitute for prescribed calcium acetate in CKD patients requiring phosphate binding, as calcium carbonate leads to more hypercalcemic events and provides less effective phosphate binding per unit of elemental calcium 2, 4