It’s drilled into us from an early age: Calcium is good for our bones.
Yet according to the National Institutes of Health, many Americans don’t get enough calcium from food and supplements, putting them at risk for bone fractures and other health problems.
Knowing the foods that contain calcium and how to safely take supplements can be beneficial to getting the calcium you need.
Why is calcium important?
Calcium has well-earned its reputation for helping in the development and maintenance of strong bones and healthy teeth. Calcium also helps ensure the proper function of muscles, nerves and enzymes. And calcium plays a vital role in heart function and blood clotting.
Calcium is mostly stored in the bones, so if your body doesn’t get enough calcium, you can develop bone problems, such as osteopenia and osteoporosis.
Osteopenia means your bone density is below normal, but not yet in the range of osteoporosis. Having osteoporosis means your bones and thin and brittle, with lots of holes inside of them, making them easy to break.
Some studies have shown a correlation between adequate calcium intake and a reduced risk of colon cancer and rectal cancer. More research is needed to better determine the link.
How much calcium do I need?
In general, people ages 19-50 need about 1,000 mg of calcium daily.
Males ages 51-70 should aim for 1,000 mg daily.
Females ages 51-70 should aim for 1,200 mg daily.
In general, everyone ages 71 and older should get 1,200 mg daily.
Who needs more calcium?
Anyone who is not getting enough calcium in their diet should try to up their intake of this important mineral. People who may be at high risk of not getting enough calcium include:
- Postmenopausal women and women who go through menopause before age 45. As women go through menopause, the amount of estrogen in their body declines. Estrogen plays an important role in regulating and absorbing calcium, so as the estrogen levels decrease during menopause, women become at higher risk of developing osteoporosis.
- Men and women ages 65 and older. Osteoporosis risk increases with age, so it’s particularly important for people ages 65 and older to get enough calcium.
- Anyone with a body mass index (BMI) less than 18.5.
- Patients with malabsorption conditions that affect their ability to absorb nutrients from food, such as those with inflammatory bowel disease or celiac disease.
- Anyone with a family history of osteoporosis.
- Those who drink an excessive amount of alcohol.
- Those who live a sedentary lifestyle.
People who have a low intake of calcium in their diet, such as vegans and people who are lactose intolerant or are allergic to milk, should talk to their physicians about ways to increase their calcium levels.
Being on certain medications can affect people’s absorption of calcium. Prednisone and some seizure medications, for example, decrease the absorption of calcium in the gut so when someone who is on these drugs eats something with calcium, the calcium won’t be adequately absorbed by the body. Proton pump inhibitors reduce the amount of acid in the stomach; acid is needed to help the body absorb calcium.
How to increase calcium safely
Check with your physician before increasing your calcium intake because too much calcium can interfere with certain medications. Also, people with certain medical conditions, such as kidney problems or hypercalcemia, should avoid too much calcium.
Those who are trying to increase their calcium levels must do so safely to avoid complications. Increasing calcium intake too quickly and consuming too much calcium overall can lead to constipation and kidney stones. Having too much calcium also can lead to poor absorption of other minerals, such as iron and zinc.
The best way to increase calcium intake safely is through food rather than supplements. Good food sources of calcium include dairy products, such as milk, cheese and yogurt. Leafy green vegetables, such as broccoli, kale and spinach, also are good sources of calcium. Other suggestions include salmon, tofu, peas, almonds, sesame seeds and fortified plant-based milk alternatives.
Calcium supplements are a convenient and easy way to increase calcium levels, but excessive intake can lead to constipation and kidney stones. Start slowly, with 500 mg, and gradually increase to the recommended levels under the guidance of your doctor. We usually advise not taking all of your calcium at once but instead spreading it out over the day to aid in the absorption of the mineral and to decrease the risk of constipation. For example, if you take two 500 mg calcium tablets a day, you may want to take one with breakfast and one with dinner.
There are different types of calcium supplements, such as calcium carbonate and calcium citrate. Both are helpful. Calcium carbonate should be taken with food whereas calcium citrate need not be.
We usually recommend taking calcium with vitamin D, which helps the body absorb calcium. The recommended dietary allowance of vitamin D is 600 international units (IU) for everyone ages 1-70, and 800 international units for adults older than 70. You likely will see mcg (micrograms) listed on food labels: 1 mcg equals 40 IU of vitamin D. Good food sources of vitamin D include cheese, eggs, beef liver and fatty fish. Many foods are fortified with vitamin D, such as orange juice, milk and many breakfast cereals.
Anyone at risk for osteoporosis should talk to doctor about supplements and how to best make dietary changes to increase calcium levels. Some patients may qualify for a DEXA scan, a test that screens for osteoporosis and evaluates risk for bone fractures.
Calcium alone is not enough to maintain strong bones. Vitamin D, regular physical activity and weight-bearing exercises also are important. I suggest eating a healthy, balanced diet with plenty of fruits and vegetables and minimizing sugar and processed foods.