Calcium: Health Benefits, Food Sources, and More

Did you know that your bones and teeth are mostly made up of calcium? In fact, 99 percent of your body’s calcium supply is stored in these body parts. In addition to literally forming the foundation of your body, calcium works in many other ways to help keep you in tip-top working order. (1)

What Is Calcium, and Why Do I Need It?

Calcium is a mineral that plays a role in many body processes, including clotting blood and releasing hormones. (2) “Calcium, the most abundant mineral in the body, is a critical building block for both bones and teeth,” says Emily Kyle, RDN, a dietitian in private practice in Rochester, New York. “Calcium also plays many important roles in some metabolic functions within the body. Adequate calcium intake is important for maintaining optimal nerve transmission and the regulation of heart muscle functions.”

Getting enough calcium throughout your lifetime can help prevent osteoporosis, a bone disease that heightens your risk of breaking bones. (2,3) It’s important to consume adequate vitamin D along with calcium, because the combination increases your absorption of the mineral. (3)

Calcium needs vary by life stage and sometimes gender. Based on the recommended dietary allowance (RDA), or the average daily level of intake deemed sufficient to meet the nutritional needs of most healthy people, children require the following:

• Children ages 1–3: 700 milligrams (mg)
• Children ages 4–8: 1,000 mg
• Children ages 9–18: 1,300 mg (4)

The RDAs for calcium change with age. One reason for this is that your ability to absorb calcium decreases as you get older: While calcium absorption can be as high as 60 percent for infants and young children, it decreases to 15 to 20 percent in adulthood, with the exception of during pregnancy. So requirements are as follows:

• Men and women ages 19–50: 1,000 mg
• Women age 51+: 1,200 mg
• Men age 51+: 1,000 mg
• Men age 71+: 1,200 mg
  
• Pregnant or lactating women ages 14–18: 1,300 mg
• Pregnant or lactating women ages 19–50: 1,000 mg (4)

Calcium absorption also varies based on the type of food the calcium comes from, other foods it’s consumed with, and how much calcium is taken in at any one time. As the amount of calcium consumed increases, how efficiently the body absorbs that calcium decreases. As a result, it’s more effective to split doses of calcium throughout the day than to take in the same total amount of calcium all at once.

The 2020 Dietary Guidelines Advisory Committee Report note calcium as a nutrient of concern. (7) This means that the nutrient has a high prevalence of inadequate intake across the U.S. population and even more so in specific groups.

People who are overweight or obese, lower socioeconomic status, and communities of color may be at the greatest risk for being deficient in calcium. (8) Age groups most at risk for insufficiency include females ages 14 to 18 and adults age 71 and older. (9)

What happens when you don’t take in enough calcium? “Consuming too little calcium for a long period of time is most commonly connected with the development of osteoporosis later in life, especially for women,” says Kyle. “Getting too little calcium through the diet or supplementation may also pose risks to heart health, as calcium helps regulate many essential cardiac functions.”

Initially, you may show no noticeable signs of a calcium deficiency. But over time, symptoms can include numbness or tingling in fingers, muscle cramping, irregular heart rhythms, loss of appetite, and lethargy. (4)

While dairy products such as milk, yogurt, and cheese are rich in calcium, these aren’t the only food sources of the mineral. “Tofu is my personal favorite calcium-rich food because it is versatile and perfect for plant-based eaters and omnivores alike,” says Kyle. To get the calcium benefits of tofu, choose an option prepared with calcium sulfate. You’ll also find calcium in canned salmon, leafy greens such as kale, and broccoli. (4)

If you’re drinking a calcium-fortified beverage, such as a nondairy milk or orange juice, the calcium could settle to the bottom of the container, so shake well before pouring.

It depends. “Both men and women require differing amounts of calcium throughout their lifetime, meaning that some people may need to take calcium supplements at a certain age to meet their recommended dietary allowance,” says Kyle. “For women, the body requires more calcium during adolescence, pregnancy, and lactation, and the postmenopausal phase. During these periods, it is wise to discuss your personal need for a calcium supplement with your healthcare provider.”

Not sure how much calcium you get from food? Log your daily eats with an app like Everyday Health’s calorie counter (which tracks nutrient intake) for about a week to see where you stand. If you fall low, consider adding more calcium-rich foods to your diet before you jump straight to supplements since the whole food version provides benefits beyond calcium alone.

If you decide to take a calcium supplement, you’ll absorb the most when you consume 500 mg or less at a time. So divide your total daily supplemental intake into two doses. (7)

The Difference Between Calcium Carbonate, Calcium Citrate, and Other Calcium Supplements

“Calcium supplements come in many forms, with the most common being calcium carbonate and calcium citrate,” says Kyle. “The most appropriate calcium supplement should be selected with your healthcare provider, based on a variety of factors, including your age, any current medical issues, and the risk for potential interactions with current medications.”

Calcium carbonate is the most commonly available calcium supplement, and it’s also the least expensive one. (4,10) You’ll absorb it best when it’s consumed with food. (4)

However, a study showed that the absorption rate isn’t good for people who are also consuming proton pump inhibitors or histamine 2 blockers (which are used in the treatment of peptic ulcers and reflux). (11) Calcium carbonate may also cause side effects such as gas, bloating, or constipation. (4) On the other hand, calcium citrate should be taken without food — and with fewer reported side effects, it’s the best supplement option for people with low gastric acid production. (4,11) Less common types of calcium supplements include calcium lactate and calcium gluconate. (4)

When it comes to calcium, more isn’t necessarily better. “Hypercalcemia, which can result if too much calcium is consumed through supplementation, can cause an increase in bone fractures,” says Kyle. And constipation can be an unwanted side effect for both men and women, she notes. Taking in calcium above the tolerable upper intake level (UL) may also lead to more serious problems, such as increased cardiovascular risk, according to a study. (12)

The UL for calcium is as follows:

• Children ages 1–8: 2,500 mg
• Children ages 9–18: 3,000 mg
• Men and Women ages 19–50: 2,500 mg
• Men and Women ages 51+: 2,000 mg
• Pregnant or lactating women ages 14–18: 3,000 mg
• Pregnant or lactating women ages 19–50: 2,500 mg (4)

Can you get this much calcium through food? It’s unlikely. You only really need to worry about overdosing on calcium through fortified foods and supplements. And keep in mind that you might be supplementing calcium through multiple sources — such as a multivitamin, a calcium supplement, and over-the-counter antacids. These antacids typically provide between 200 mg and 400 mg calcium per tablet. (4)

As for interactions with medication, you do need to be concerned with this, as some will negatively interact with calcium. For instance, calcium supplements can decrease absorption of bisphosphonates used to treat osteoporosis. (4) You can run a list of your medications and supplements at the Drug Interactions Checker at Drugs.com for potential interactions, but it’s still a good idea to speak with your doctor and pharmacist before starting any new medication.

How Do I Know if I Have a Calcium Deficiency?

Symptoms of calcium deficiency include numbness and tingling in the fingers, muscle cramps, convulsions, lethargy, poor appetite, and abnormal heart rhythms. (4) If you suspect your calcium intake is too low — or if you have any of these symptoms — speak with your doctor about getting some tests run. It’s also possible to have no symptoms but have a low-level calcium deficiency that does increase health risks. It’s best to make sure you’re getting adequate daily calcium intake from foods.

What Foods Are High in Calcium?

A food is considered high in calcium when it contains 20 percent or more of the daily value for the mineral. The daily value for calcium is 1,000 mg, so foods high in calcium could contain 200 mg or more per serving. Foods high in calcium include yogurt, cheese, milk, calcium-fortified soy milk and orange juice, canned sardines (that contain the bones), and tofu made with calcium sulfate. (4)

Can I Get Too Much Calcium?

Yes, there is such a thing as too much calcium! Although taking in too much from food is unlikely, you can overconsume calcium through fortified foods and supplements. Before beginning a calcium supplement regimen, speak with your doctor to make sure you need it and that it’s safe to pair with any medication you are taking.

What Is a Calcium Channel Blocker?

A calcium channel blocker prevents calcium from entering the cells in the heart and blood vessel walls — helping to lower blood pressure. It may also help treat coronary artery disease, chest pain, irregular heartbeat, and certain circulatory conditions, such as Raynaud’s disease. (13)

Shopping for a calcium supplement? Here are the top selling options on Amazon:

• Citracal Petites Calcium Citrate
  
• Garden of Life Raw Calcium Supplement
• Nature Made Calcium Magnesium Zinc
  
• New Chapter Calcium Supplement With Vitamin K2 + D3
  
• Nature Made Calcium with Vitamin D