Key takeaways:
Calcium is the most abundant mineral in your body. And it does more than keep your bones strong. It helps with muscle strength, nerve conduction, and even blood clotting.
Most people get enough calcium from their diet. But if you take a supplement, it’s possible to take too much — leading to high calcium levels in the blood.
Too much calcium in the blood can be dangerous. It can lead to health complications, like a low heart rate or high blood pressure.
Save on related medications
When you’re experiencing heartburn, you might reach for an antacid with calcium — like Tums or Rolaids. Or maybe you’re taking calcium supplements to help keep your bones strong. But unlike other nutritional supplements, it’s possible to take too much calcium.
For most adults, experts recommend staying below 2,000 mg to 2,500 mg of calcium each day, depending on your age. This includes calcium from your diet and supplements. But you only need about half that to get your daily recommended dose.
So, let’s review how to stay safe when taking calcium supplements, along with how much is too much.
Search and compare options
How much calcium is safe to take?
To be safe when taking calcium, it’s important to stay within the recommended daily amounts. This is the amount of daily calcium needed by most healthy people.
Before we dive into how much calcium is safe to take, there are a few things to keep in mind:
Certain health conditions, medications, and other factors can affect how much calcium is safe to take. Your healthcare team should be able to tell you what a safe dose is for you.
The recommended amounts (see below) include calcium from both your diet and supplements.
Your body is only able to absorb a certain amount of calcium from supplements at a tim: about 500 mg. If you rely on supplements to get enough calcium, you may need to divide your daily amount into smaller doses taken twice daily.
Age | Recommended daily amount |
|---|---|
Babies up to 6 months | 200 mg |
Infants ages 7 to 12 months | 260 mg |
Children ages 1 to 3 | 700 mg |
Children ages 4 to 8 | 1,000 mg |
Children and adolescents ages 9 to 18 | 1,300 mg |
Adults ages 19 to 50 | 1,000 mg |
Adult men ages 51 to 70 | 1,000 mg |
Adult women ages 51 to 70 | 1,200 mg |
Adults ages 71 and older | 1,200 mg |
How much calcium is too much?
In addition to recommended daily intake amounts, experts provide maximum amounts you should stay below each day. Taking more than the maximum amount may lead to side effects and other health risks, which we review below.
Age | Maximum daily amount |
|---|---|
Babies up to 6 months | 1,000 mg |
Infants ages 7 to 12 months | 1,500 mg |
Children ages 1 to 3 | 2,500 mg |
Children ages 4 to 8 | 2,500 mg |
Children and adolescents ages 9 to 18 | 3,000 mg |
Adults ages 19 to 50 | 2,500 mg |
Adults ages 51 to 70 | 2,000 mg |
If you have certain medical conditions, the maximum amount may be different. For example, people with chronic kidney disease (CKD) are at risk for high blood levels of minerals like calcium and phosphorus. And so too much calcium can cause problems in your heart, blood vessels, and bones.
The National Kidney Foundation recommends limiting calcium to less than 2,000 mg per day if you have CKD. This includes calcium from your diet, supplements, and other medications.
What medications and supplements should I be careful to mix calcium supplements with?
Calcium can affect the absorption of certain medications when you take them at the same time. Most commonly, these include certain antibiotics, thyroid medications, and osteoporosis medications.
There are also some medications and supplements that can increase calcium levels in the blood. And when they’re combined with calcium supplements, your calcium levels may get too high. Examples of these include:
Lithium (Lithobid)
Thiazide diuretics, like hydrochlorothiazide (Microzide)
Vitamin D supplements
Teriparatide (Forteo)
Read more like this
Explore these related articles, suggested for readers like you.
To help avoid this, make sure your healthcare team has a complete list of all the medications and supplements you take. They can check for potential interactions with your calcium supplements.
How can you tell if you’ve taken too much calcium?
Taking too much calcium can lead to high calcium levels in the blood. The medical term for this is hypercalcemia. It’s usually caused by an overactive parathyroid gland or cancer. But it can also happen just from taking too much calcium. This may be more likely if you’re combining it with other medications or supplements that increase calcium levels.
It may also happen if you’re taking too much calcium carbonate, which is the main ingredient in certain antacids like Tums. This can lead to something called milk-alkali syndrome, which leads to high calcium levels and shifts in your body’s acid/base balance. This can be harmful to your kidneys.
A high calcium level may not cause many symptoms at first. But eventually it can affect many different organ systems and cause the following symptoms:
Constipation
Stomach pain
Loss of appetite and nausea/vomiting
Increased thirst
Increased or decreased urination
Mood changes
Disorientation and confusion
Bone pain
Muscle weakness and fatigue
Hypercalcemia can also lead to other problems, like:
Pancreatitis
Heart rhythm problems or low heart rate
Peptic ulcer disease
Kidney stones, but this is less likely to happen from calcium supplements
Low heart rate
High blood pressure
Let a healthcare professional know if you’re experiencing these symptoms while taking a calcium supplement, including antacids like Tums.
What should I do if I accidentally take too much calcium?
If you’re concerned that you or a loved one took too much calcium, or has high calcium levels, it’s important to seek medical help. If your symptoms are severe, go to your nearest emergency room (ER). This is especially important if you’re experiencing:
Disorientation
Confusion
Trouble staying awake
Repeated vomiting
A significant decrease in urination, or dark brown urine
Severe hypercalcemia requires immediate treatment in a hospital.
If you’re worried you took too much calcium but don’t have any symptoms, you can also contact Poison Control at 1-800-222-1222. The center can provide recommendations based on how much calcium you took.
Frequently asked questions
Calcium supplements come in several different types. The most common forms include calcium carbonate and calcium citrate. Others include calcium gluconate and calcium lactate. Each of these forms contain different amounts of calcium, with calcium carbonate containing the most. Calcium supplements are typically taken by mouth in the form of tablets, chewable tablets, or capsules.
You can also find calcium in multivitamins and some combination products, usually with vitamin D. Common OTC antacids, like Tums and Rolaids, contain calcium carbonate.
Calcium-rich foods include:
Dairy products, like milk, cheese, and yogurt
Vegetables, like spinach and kale
Fish with soft, edible bones, like sardines
Drinks (like juices or soy milk) that have calcium added to them
Food and drink items will usually have the amount of calcium listed on their nutrition facts label. This can help tell you how much calcium is in each serving.
Your body uses calcium for many different functions. About 99% of your body’s calcium is stored in your bones and teeth. This helps keep them strong and hard. But your body also uses calcium for other purposes. Your muscles use calcium to move and contract. Your nerves use calcium to send signals between your brain and other parts of your body. It’s also important for blood flow and releasing certain hormones in your body.
Calcium supplements come in several different types. The most common forms include calcium carbonate and calcium citrate. Others include calcium gluconate and calcium lactate. Each of these forms contain different amounts of calcium, with calcium carbonate containing the most. Calcium supplements are typically taken by mouth in the form of tablets, chewable tablets, or capsules.
You can also find calcium in multivitamins and some combination products, usually with vitamin D. Common OTC antacids, like Tums and Rolaids, contain calcium carbonate.
Calcium-rich foods include:
Dairy products, like milk, cheese, and yogurt
Vegetables, like spinach and kale
Fish with soft, edible bones, like sardines
Drinks (like juices or soy milk) that have calcium added to them
Food and drink items will usually have the amount of calcium listed on their nutrition facts label. This can help tell you how much calcium is in each serving.
Your body uses calcium for many different functions. About 99% of your body’s calcium is stored in your bones and teeth. This helps keep them strong and hard. But your body also uses calcium for other purposes. Your muscles use calcium to move and contract. Your nerves use calcium to send signals between your brain and other parts of your body. It’s also important for blood flow and releasing certain hormones in your body.
The bottom line
Calcium is an important mineral involved in many different functions in your body. Most people get enough calcium from their diet, but some need to take calcium supplements to make up the difference.
Staying within the recommended intake amounts of calcium is generally safe. But it’s possible to get too much calcium from supplements. This can cause calcium levels in your blood to get too high. And this may be more likely if you’re taking other medications or supplements that increase calcium levels too.
Why trust our experts?
References
Amberg, G. C., et al. (2013). Calcium dynamics in vascular smooth muscle. Microcirculation.
Bargagli, M., et al. (2021). Calcium and vitamin d supplementation and their association with kidney stone disease: A narrative review. Nutrients.
Goltzman, D., et al. (2018). Physiology of the calcium-parathyroid hormone-vitamin D axis. Frontiers of Hormone Research.
MedlinePlus. (2023). Milk-alkali syndrome.
MedlinePlus. (2024). Calcium.
National Capital Poison Center. (n.d.). Get poison control help.
National Institutes of Diabetes and Digestive and Kidney Diseases. (2021). Mineral and bone disorder in chronic kidney disease.
National Institutes of Health Office of Dietary Supplements. (2022). Calcium.
National Kidney Foundation. (2003). KDOQI clinical practice guidelines for bone metabolism and disease in chronic kidney disease.
Sadiq, N. M., et al. (2021). Hypercalcemia. StatPearls.
