Everyone needs calcium, right? It seems many people are concerned about avoiding osteoporosis. No one wants to end up being painfully hunched over while using a cane or walker.
So should we all load up on calcium supplements? Not so fast. Too much calcium can crowd out other nutrients and cause kidney stones and constipation. Interactions with meds can be serious, and there’s a hint that calcium supplements may boost the risk for heart disease.
Though calcium is needed for various bodily functions to work well, it mainly helps to keep bones and teeth strong. “Calcium is crucial for optimal bone health throughout your life,” says Taz Bhatia, MD, an integrative health expert and founder of CentreSpring MD, an Atlanta medical practice. Without enough of the mineral, you may have a higher risk of bone fractures or osteoporosis, which become more common with age as bones become thinner. Calcium is helpful for increasing bone density in people with and without osteoporosis.
Who Needs Supplements
Before you start taking calcium supplements, your doctor should test your blood to gauge your nutrient levels. It’s important to check that all your minerals are in balance, because some “might get crowded out by calcium in the gut, such as zinc, which is an important mineral involved in many reactions in the body,” says Dr. Fraser Smith, chief academic officer for the naturopathic medicine program and assistant dean for naturopathic medicine at National University of Health Sciences in Lombard, Ill.
So who is at an elevated risk of having low calcium levels? Vegans and people with lactose intolerance (https://my.clevelandclinic.org/health/articles/the-role-of-calcium-in-preventing-osteoporosis) for starters, since they avoid many foods and beverages that are rich in the nutrient.
Both protein and sodium work to remove calcium in your body. If you are on a high-protein diet or tend to be attracted to salty foods, it could affect your calcium levels.
“I’ve also had patients with serious digestive issues like irritable bowel syndrome or celiac disease that have affected their ability to absorb calcium, and therefore they need an extra source of calcium,” says Dr. Bhatia.
Drug Interactions With Calcium
Despite the bone-building boost that these supplements may provide, there can be disadvantages in certain cases. “One downside is that calcium supplements may interact with certain medications and may make it harder for them to work,” according to Mohamed A. Jalloh, PharmD, assistant professor at Touro University California College of Pharmacy and spokesman for the American Pharmacists Association. “An example is a newer HIV drug named Tivicay [dolutegravir],” he says. “Calcium makes it harder for this medication to work and requires patients to separate the doses by a few hours.”
It might seem logical to take calcium supplements if you have osteoporosis, but check with your healthcare provider if you are taking one of the medications typically used for the condition, such as Fosamax (alendronate), Actonel (risedronate) or Boniva (ibandronate). A calcium supplement may interfere with absorption of these drugs.
Taking a calcium supplement can also boost the risk of a toxic reaction with the irregular heartbeat medication Lanoxin (digoxin).
Other drugs and over-the-counter products that calcium supplements may interfere with include antacids that contain aluminum, some blood pressure medication, certain diuretics (hydrochlorothiazide, furosemide and bumetanide), which are used to treat fluid retention, some antibiotics – Levaquin (levofloxacin), Cipro (ciprofloxacin) and ones known as tetracyclines – and some seizure meds.
Your Body Doesn’t Want Too Much
Adverse effects can occur if you overdo your intake. “Most of us only need 1,000-1,200 mg of calcium each day, and any more than that can lead to constipation and may even increase the risk of kidney stones,” Dr. Taz cautions.
And going really wild with the supplements can seriously damage the heart and kidneys due to elevated calcium levels in the blood, adds Dr. Smith.
Where You Get Calcium From Counts
It’s important to note that you should get as much calcium daily as possible from foods, rather than rely on supplements. Why? First, the body typically absorbs more calcium if it comes naturally. Your body can absorb about 30% of the calcium present in dairy products, such as milk, but 50% in certain vegetables (Brussels sprouts, kale, mustard greens, broccoli, bok choy, cauliflower), as well as foods that are fortified with calcium. And eating stimulates the production of stomach acid, which also boosts absorption.
By comparison, the body can only absorb 20-40% of the calcium present in a supplement. In addition, some people can experience gastrointestinal side effects from the supplements. And as mentioned before, calcium supplements can interfere with the body’s ability to absorb zinc and iron, as well as other medications you may be taking.
There are plenty of foods to choose from to meet your calcium needs, which may minimize the amount of a calcium supplement you need to take, if you need one at all. Aside from the well-known sources like milk, cheese and yogurt, you can get significant amounts from vegetables like kale, broccoli and collard greens, as well as some fish, like sardines and salmon. Many cereals and fruit juices are also fortified with calcium.
So just how much calcium do you need per day? Well, that depends mostly on sex, age and other health factors. Here are helpful guidelines from the Mayo Clinic:
Calcium: Recommended Dietary Allowance (RDA) for adults
|Men||Daily RDA||Daily Upper Limit|
|19-50 years||1,000 mg||2,500 mg|
|51-70 years||1,000 mg||2,000 mg|
|71 and older||1,200 mg||2,000 mg|
|Women||Daily RDA||Daily Upper Limit|
|19-50 years||1,000 mg||2,500 mg|
|51 and older||1,200 mg||2,000 mg|
|Chart courtesy: Mayo Clinic|
Men up to age 50 shouldn’t take more than 2,500 mg daily and those 51-70 should avoid taking more than 2,000 mg daily.
Women up to age 50 should take no more than 2,500 mg daily. Women 51 and over should take no more than 2,000 mg daily, max. Exceeding the upper limits can lead to side effects and potential health problems.
Because calcium comes in different forms in supplements, it’s important to take ones that have the most active amount of the mineral, known as elemental calcium. Calcium carbonate supplements contain the most elemental calcium — 40% — followed by calcium citrate, with 21%. Some common name brands with calcium carbonate are Os-Cal and Caltrate, while calcium citrate is found in Citrucel and Solgar.
A Link to Heart Disease?
There have been concerns that calcium supplements may increase the risk of heart disease. Some doctors and researchers believe that excessive amounts of calcium can make their way into fatty plaque in arteries and cause them to harden (atherosclerosis), which boosts the risk for heart disease. An October 2016 study published in the Journal of the American Heart Association involving more than 2,700 people in a heart disease study found that there was an association between those taking calcium supplements and coronary artery calcification, a measure of atherosclerosis. But those who achieved their calcium goals through diet alone didn’t share that risk.
Jalloh says the talk about calcium supplements and heart disease is inconclusive, noting that most research has confirmed that they are generally safe. “After reviewing all of the important studies, the consensus actually showed (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4384676/) that calcium supplements are not linked with heart disease,” he says. “In multiple studies, calcium and vitamin D supplementation actually helped people live longer.”
To choose and use calcium supplements wisely, heed these additional expert tips:
1. Try Food First
Dr. Taz suggests incorporating high-calcium foods into your diet before turning to supplements, and emphasizes the importance of discussing the topic with your healthcare provider first.
2. Don’t Overdo It
Remember that the recommended daily allowance for calcium is 1,000 to 1,200 mg, and you are likely already getting a good portion of this from your diet. To avoid overdoing it, read food and beverage labels to check the amount of calcium they provide toward the recommended amount. “If a label lists ‘Calcium 25%,’ that means that you will be consuming 250 mg of calcium per serving,” Jalloh notes. If you find that you are meeting the recommended amount through your diet, you may not need to take supplements unless advised by your doctor.
3. Vitamin D Helps Calcium Be Absorbed
Calcium is absorbed best when taken with food, and low levels of vitamin D affect absorption as well. “Without enough vitamin D, we do not absorb calcium well and we excrete it from the kidney too readily,” Dr. Smith explains. Calcium supplements that contain vitamin D can be helpful, and natural sources of vitamin D include dairy, fish, and limited sun exposure. Experts suggest that people get 15 to 30 minutes of sun exposuredaily.
4. Check With a Pharmacist
Though this advice applies to many types of drugs and supplements, patients “should always ask their pharmacist to double-check their medications to ensure that none of them interact with calcium,” Jalloh recommends.
Tori Rodriguez, MA, LPC is an Atlanta-based journalist, psychotherapist & health coach