How to Choose the Best Calcium Supplement in 2024

Calcium is an important mineral that is required for bone strength and healthy teeth. There are many food sources of calcium, but restricted diets, food allergies, or aging can change how well the body absorbs this mineral. Calcium supplements are sometimes recommended to support a healthy intake. In this article, we’ll cover the basics of calcium supplementation, how to choose the one that’s right for you, and other important FAQs.

What are Calcium Supplements?

Calcium supplements provide this important mineral in a capsule or tablet form. While they can’t replace the calcium needed from a balanced diet, they can support healthy intake for people who may need more.

Reasons why someone may need a calcium supplement

Calcium is the primary mineral found in the bones, so the body needs a steady supply of it from the diet. Since bone density decreases with age, and calcium absorption from food may also decline with age, supplements are often recommended by healthcare providers for people who are over age 40 with bone density issues.

People who have dairy allergies or lactose intolerance or who follow a vegan or vegetarian diet that is low in calcium may also find that their healthcare provider suggests a calcium supplement. Another reason why someone might need more calcium support includes gastrointestinal absorption issues.

It’s important to talk with your doctor about calcium supplements before starting any.

The importance of calcium in the body

In the body, 99% of calcium is stored in the bones and teeth. The other 1% isn’t unimportant — it’s still needed for muscle, blood vessels, and hormone balance in the body. After age 30, bone mass accumulation slows down. If you have a diet low in calcium, your body will withdraw calcium from the bones and teeth to meet the body’s other calcium needs. Over time, this can lead to more increased bone density loss. That’s why a calcium-rich diet is important.

Calcium becomes especially important for people born female who are perimenopausal and postmenopausal. They’re more likely to lose bone density more quickly, which can lead to many age-related complications.

Different Types of Calcium Supplements

Calcium comes in several different forms. They differ in some ways, such as absorption rate.

Calcium Carbonate

Calcium carbonate is one of the most common types of calcium found in supplements. This form requires plenty of stomach acid to break down during the digestive process, so it needs to be taken with meals. Someone who has compromised gastrointestinal health or other GI issues may not be able to get the full benefits from this form.

It has the potential to cause constipation or bloating.

Calcium Citrate

Calcium citrate is the other most common type of calcium supplement. This type requires less stomach acid for absorption, so it may be more absorbable by people with low stomach acid (or who take acid reducing medication, as well as those who are older or have other digestive conditions.

Calcium Lactate

This is a less common form for calcium supplements because it has a much lower absorption rate because it contains less elemental calcium. This means that it would take a much larger serving size of capsules to achieve the same equivalent of calcium carbonate.

Calcium Gluconate

Calcium gluconate has a lower absorption rate than carbonate or citrate forms, with even less elemental calcium than the lactate form. It’s also not a go-to choice for supplements because it would require a larger serving size and be more expensive.

Calcium Phosphate

Calcium phosphate also requires higher levels of stomach acid (like the carbonate form) but doesn’t absorb as well in the gut, making it a less common choice than carbonate or citrate. It’s also more expensive per serving, so it isn’t used as frequently for supplement formulations.

How to Choose the Best Calcium Supplement for you

When considering what matters in the best supplement for your needs, it’s important to note the form, ingredients, third-party testing, and other factors.

Form

The form of calcium supplement you take can impact how well it absorbs. You’ll need to consider the form of the nutrient (as noted above, carbonate and citrate are the most absorbed forms) and the way it is formulated. Most calcium supplements come as capsules, but can also be tablets or in a chewable form.

Ingredients

The main ingredient in your calcium supplement will be a form of calcium. Sometimes calcium is paired with other nutrients, like vitamin D, or it can be found in a multivitamin.

Supplements also contain other ingredients, like the capsule, excipients, flavors, or sweeteners. It’s important to read the label closely if you have food allergies or sensitivities, or if you follow a special diet.

Dosage

As with many things, more is not always better. Calcium supplements cannot be absorbed at doses higher than 500 mg at one time. If your medical provider wants you to take more than this per day, they’ll likely instruct you to spread your supplement intake throughout the day.

Most calcium supplements range in dosage from 150–500 mg. Always follow the instructions on your supplement and your healthcare provider’s guidance.

While the recommended dietary allowance (RDA) for calcium is 1,000 mg for all adults up to age 50 (and increases to 1,200 mg per day for people born female who are 51 and older and for people born male who are 71 and older), you should not get all of your daily calcium from supplements. If you need calcium support, your healthcare provider will let you know how much you should get from food and how much to take from supplements.

Third party testing

Supplements aren’t legally required to be tested for purity, but brands can utilize additional certifications and testing to demonstrate their quality. These certifications come from independent labs or organizations who provide consumers with information about supplement quality and label accuracy.

Some examples of these third-party certifications include:

• Certified C.L.E.A.N.
• NSF
• ConsumerLab

Brand Reliability

When choosing a supplement, brand reliability and quality is important. You’ll want to look for qualities such as:

• Third-party testing
• “Free from” allergens, GMOs, or other ingredients that align with your dietary preferences
• Vegan, vegetarian, kosher, or halal based on your dietary values
• Availability
• Pricing and serving size

Many unverified supplement products flood the market each year, so checking that the brand you’re using has a website with company information about quality can be a simple, easy way to ensure that you’re getting a high-quality, legitimate product.

Potential Side Effects

Always take calcium supplements as directed. Even when you do, calcium carbonate can lead to mild gastrointestinal discomfort. If you experience this, calcium citrate may be a more easily absorbed form that leads to fewer side effects.

Taking calcium supplements at higher doses, or if you have certain medical conditions, can cause issues. Work with your healthcare provider to determine the best supplement approach for you, and always let them know if you experience side effects or discomfort.

Frequently Asked Questions

What are natural sources of calcium?

There are many natural sources of calcium, including:

• Yogurt (415 mg in an 8 oz serving)
• Fortified orange juice (349 mg in 8 oz)
• Mozzarella cheese (333 mg in 1.5 oz)
• Bone-in sardines (325 mg in 3 oz)
• Milk (299 mg in 8 oz)
• Fortified soy milk (299 mg in 8 oz)
• Cottage cheese (138 mg in 8 oz)
• Cooked soybeans (131 mg in 4 oz)

The average daily intake of calcium in the U.S. is between 900–1,000 mg. Calcium supplements can support an adequate intake of this nutrient.

Does calcium interact with other drugs?

Yes, like other supplements, calcium has the potential to interact with other medications or supplements. Calcium can reduce the absorption of iron, and can also interact with thyroid medication, certain antibiotics, and other prescriptions. Always check with your healthcare provider before starting a new supplement, and make sure they’re aware of the other things that you take.

How much calcium should you take?

Taking more than 500 mg of calcium at one time isn’t suggested since that is the max amount that the body can absorb at one time. Calcium supplements range from serving sizes of 100–500 mg. Follow your medical provider’s recommendations for how much calcium you should take.

What is the best form of calcium?

Calcium carbonate and calcium citrate have similar absorption rates, so either are a good choice. Calcium citrate may produce fewer gastrointestinal symptoms and does not have to be taken with meals, which may make it more convenient.

Is vitamin D the same as calcium?

Vitamin D is a fat-soluble vitamin, while calcium is a mineral. They are not the same, but calcium is dependent on vitamin D for absorption. Both are needed for bone and overall health.

Can you take vitamin D and calcium together?

The absorption of calcium depends on adequate vitamin D, so they are often formulated together for convenience. Vitamin K is another nutrient that is needed for bone health and calcium absorption in the intestines.

Can you overdose on calcium supplements?

Yes, you can take too much calcium from supplements. Always follow your medical provider’s guidance and the instructions on your calcium supplement label. The upper limit for calcium intake for adults is 2,500 mg, but the body cannot absorb more than 500 mg at a time. Additionally, even with a reason to need more calcium, the RDA is less than half the upper limit, so that much is not needed.

Too much calcium does have the potential to lead to some complications. The body absorbs more calcium from food and supplements when intake is too low. When it is on the higher end, the body will absorb less, removing what’s not needed via the kidneys. However, excess calcium frequently being filtered by the kidneys can contribute to calcium deposits, which can lead to kidney stones.

Excess calcium intake can also disrupt other mineral balance in the body, like zinc and iron.

The Bottom Line

Your bones, teeth, and entire body depend on calcium to function optimally. It’s best to get plenty of calcium from the food that you eat, but in some cases, calcium supplements can support adequate intake. There are several forms of calcium, with different absorption rates, but carbonate and citrate are the most common forms. When you’re searching for the best calcium supplement for you, it’s also important to consider brand quality, dosage, and whether the supplement has been independently certified for quality.