Calcium Acetate Overdose: Symptoms, Risks, and What to Do

When you take calcium acetate, a phosphate binder used mainly for people with kidney disease to control high phosphorus levels. Also known as Phoslo, it helps stop your body from absorbing too much phosphorus from food. But if you take too much, it can push your calcium levels dangerously high — a condition called hypercalcemia, a buildup of calcium in the blood that can damage organs and disrupt heart rhythm.

People on dialysis or with chronic kidney disease are most at risk because their kidneys can’t flush out extra calcium. Taking more than prescribed — whether by accident, confusion, or trying to speed up results — can cause nausea, vomiting, confusion, extreme thirst, and frequent urination. In severe cases, it leads to irregular heartbeat, muscle weakness, or even kidney stones. This isn’t theoretical: real cases have been reported where patients doubled their dose thinking it would help more, and ended up in the ER. Calcium acetate doesn’t work faster with higher doses — it just becomes toxic.

It’s not just about the pill count. Other things can make overdose worse. Taking calcium acetate with vitamin D supplements, antacids, or other calcium-based products stacks up the total calcium load. Some people don’t realize their multivitamin already contains calcium, or they’re taking Tums for heartburn on top of their prescribed binder. That’s a hidden double dose. Also, if your kidney function drops suddenly — say, from dehydration or an infection — your body can’t clear calcium the way it used to, making even normal doses risky.

What should you do if you suspect an overdose? Stop taking the medication immediately. Call your doctor or poison control — don’t wait for symptoms to show up. Blood tests will check your calcium, phosphorus, and kidney function. Treatment might include IV fluids to flush out excess calcium, or medications to lower it fast. In rare, severe cases, dialysis is needed. Prevention is simple: always take it exactly as prescribed, with meals, and never adjust your dose without talking to your care team. Keep a list of all your meds — including supplements — and review it with your pharmacist every few months.

There’s a reason your doctor chose calcium acetate over other phosphate binders like sevelamer or lanthanum. It’s cheaper, widely available, and works well — if used correctly. But it’s not a one-size-fits-all solution. If you’re struggling with side effects or keeping track of your pills, ask about alternatives. Some people do better with non-calcium binders, especially if they already have high calcium levels. Your treatment plan should adapt as your health changes.

Below are real-world guides from others managing similar conditions — from understanding how calcium acetate fits into daily kidney care, to spotting when other meds might be safer. You’ll find practical advice on avoiding hidden calcium sources, recognizing early warning signs, and talking to your doctor about switching treatments if needed. This isn’t just about one drug — it’s about staying in control of your health when you’re juggling multiple meds and complex needs.