How Important Is Calcium to My Health?

What is calcium?

You might be aware that the mineral calcium is important for strong bones and teeth. But calcium is also important for the health of your muscles (including your heart), nerves, and blood. It's the most abundant mineral in your body.

However, the human body does not contain enough calcium on its own, and most Americans don’t get enough calcium in their diets. Calcium supplements are a useful way to get the needed amount.

Calcium: Sources and supplements

Your body doesn’t make calcium, so it’s important to get it through diet and supplementation. The good news is that many foods contain calcium. The most well-known source is dairy, but several other types of foods are also rich in calcium. They include:

• Dairy products such as milk, yogurt, or cheese

• Leafy greens such as kale, collard greens, and spinach

• Nuts and seeds such as almonds, hazelnuts, and sesame seeds

• Fortified foods such as cereals, orange juice, and plant milks

• Beans and grains such as white beans, chickpeas, and quinoa

It’s best to get your calcium from foods. But if you can’t, calcium supplements can help bridge the gap. Examples include:

• Calcium carbonate (40% calcium)

• Calcium citrate (21%)

• Calcium lactate (13%) 

• Calcium gluconate (9%)

Calcium supplements come in tablets or chewables. Calcium carbonate is commonly found in antacids such as Rolaids or Tums. You can also find supplements that contain both calcium and vitamin D, because your body needs vitamin D to absorb calcium. 

Calcium supplements dosing

Experts recommend the following amounts for total daily intake of calcium (including diet and supplements): 

• 1,000 mg for adults aged 19 to 50 

• 1,000 mg for men over 50 years old

• 1,200 mg for women over 50 years old

• 1,200 mg for adults over 70 years old 

And if you need to take a calcium supplement, keep in mind that you’ll only absorb about 500 mg at a time. So you’ll want to divide the daily amount into smaller doses twice a day to get the most from your supplement.

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How much calcium is too much?

Experts recommend no more than 2,500 mg per day for most adults up to age 50, and no more than 2,000 mg per day for people over 50. They also recommend getting no more than 500 mg of calcium at once. So, if you need to supplement more than 500 mg of calcium in one day, consider splitting the dose.

Common uses for calcium supplements

Common uses of calcium include the following: 

• Osteoporosis treatment and prevention

• Treatment of low blood-calcium levels

• Indigestion and heartburn treatment (in antacids)

• Correction of electrolyte imbalances (typically in a hospital setting)

Calcium supplements have also been shown to reduce the risk of preeclampsia in women who don’t get enough calcium. This is rarely needed in the U.S. or other developed countries, where diets are higher in calcium.

Research is ongoing, but it’s too soon to say if calcium can help with:

• Colon cancer prevention

• High blood pressure in young adults

• Risk of metabolic syndrome

• Weight loss

What does science say about calcium supplements?

Bone loss happens as we age, and calcium deficiency can contribute. There are many health risks associated with broken bones (fractures), so it’s important to keep your bones as strong as possible. That’s why experts recommend calcium supplementation for people who don’t get enough calcium in their diet. Research suggests that calcium supplementation can help preserve bone strength and maybe even increase bone-mineral density. 

There is also growing evidence that calcium may help prevent high blood pressure in young adults. But the optimal dose and method (diet versus supplementation) for this isn’t quite clear. Calcium is not recommended as a treatment for high blood pressure.

Controversy exists over the effect of calcium supplementation on cardiovascular health because studies are mixed. Recent work suggests a calcium-rich diet may be beneficial for heart health, but supplements might increase the risk of heart disease. 

Calcium supplement interactions

Calcium can affect how your body absorbs certain medications. This can happen if you eat calcium-rich foods (e.g., dairy products) or take calcium supplements at the same time as other medications. You may be advised to separate calcium and your medication dose by a few hours to avoid this interaction.

Examples of medications that can interact with calcium supplements include:

• Tetracycline antibiotics like doxycycline (Vibramycin)

• Fluoroquinolone antibiotics like ciprofloxacin (Cipro)

• Thyroid medications like levothyroxine (Synthroid)

• Bisphosphonates like alendronate (Fosamax)

• Dolutegravir (Tivicay)

• Iron supplements

Some medications and supplements can raise calcium levels in your blood. When they’re combined with calcium supplements, your calcium levels could potentially get too high. If you’re taking any of these, your healthcare provider may want to monitor your levels.

Examples include:

• Lithium (Eskalith)

• Thiazide diuretics like hydrochlorothiazide (Microzide)

• High doses of vitamin D

These examples don’t include all potential interactions with calcium. Make sure your healthcare provider and pharmacist have your current medication list (including over-the-counter products and supplements) to check for interactions.

Side effects of calcium supplements

Most commonly, calcium supplements can cause constipation. Other side effects can include:

• Burping

• Upset stomach

• Abdominal pain

• Dry mouth

• Metallic taste in your mouth

Safety of calcium supplements

If any of the above side effects become severe, contact your healthcare provider right away. This could be a sign your calcium levels are too high. 

Other signs your calcium levels might be too high include:

• Nausea

• Vomiting

• Feeling very tired

• Weight loss

• Needing to pee more often

• Fast or irregular heartbeat

High levels of calcium in your blood and urine can affect your kidneys and potentially put you at higher risk of getting kidney stones. This isn’t as common with calcium supplements, but it may be possible if you’re taking higher doses.

Most kidney stones are able to pass on their own. But if you’re experiencing severe or worsening pain, or you have signs of an infection (fever, chills), get medical attention.  

FAQs

Disclaimer: The FDA does not test supplements for safety and effectiveness. Supplements can contain harmful substances. They can also affect how your medications work. Always speak with your healthcare provider before taking any supplement.

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Written by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined clinical medicine with her passion for education and content development for many years. She served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

Edited by:

Amy B. Gragnolati, PharmD, BCPS

Amy Gragnolati, PharmD, BCPS, is a pharmacy editor for GoodRx. Amy currently holds her pharmacist license in Georgia and California.

Reviewed by:

Alyssa Billingsley, PharmD

Alyssa Billingsley, PharmD, is the director of pharmacy content for GoodRx. She has over a decade of experience as a pharmacist and has worked in clinical, academic, and administrative roles.

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