Calcium is important for strong bones. While not enough can lead to osteoporosis, too much might be linked to heart issues. This article breaks down the right dosage for calcium supplements.
Many take these supplements for better bone health.
But, there might be downsides to calcium pills, including possibly increasing heart disease risk.
Read on to understand the ins and outs of calcium supplements: who should consider them, their benefits, and possible risks.
In this article
Why do you need calcium?
Calcium is crucial for strong bones and teeth, making up over 98% of their composition.
It also helps in our blood by transmitting nerve messages, releasing important hormones, and controlling muscle movement and blood vessel size.
If you don’t eat enough calcium, your body will take it from your bones and teeth, which isn’t good for their strength.
So, how much calcium should you be getting daily?
Below are the current recommendations from the Institute of Medicine, by age:
- Women ages 50 and younger: 1,000 milligrams (mg) per day
- Men ages 70 and younger: 1,000 mg per day
- Women over age 50: 1,200 mg per day
- Men over age 70: 1,200 mg per day
There are also recommended upper limits for calcium intake. The cap is 2,500 mg per day for adults up to age 50 and 2,000 mg per day for adults over age 50.
It’s possible to get sufficient amounts through your diet. Foods that contain calcium include dairy products, certain leafy greens, nuts, beans, and tofu.
However, people who don’t eat enough calcium-rich foods might consider taking supplements.
Summary: Calcium helps our bones stay strong, supports nerve messaging, and aids in muscle movement. While many can get enough from food, others might need extra help from supplements.
Who should take calcium supplements?
When your calcium intake is insufficient, your body will remove calcium from your bones, making them weak and brittle. This can result in osteoporosis.
Since women are at a higher risk of osteoporosis, many doctors recommend taking calcium supplements, especially after menopause. Because of this, older women are much more likely to take calcium supplements.
If you don’t get the recommended amount through your diet, supplements can help fill the gap. You might also consider calcium supplements if you:
- follow a vegan diet
- have a high protein or high sodium diet, which may cause your body to excrete more
- calcium
- have a health condition that limits your body’s ability to absorb calcium, such as
- Crohn’s disease or inflammatory bowel disease
- have a history of gastric bypass surgery
- are being treated with corticosteroids over a long period of time
- have osteoporosis
Summary: Calcium supplements may benefit those not getting enough calcium from food and women who have reached menopause.
Health benefits of calcium supplements
Calcium supplements may have several health benefits.
Calcium supplements may help prevent bone loss in postmenopausal women
After menopause, women lose bone mass due to a decline in estrogen.
Supplements may help. Several studies have suggested that postmenopausal women taking calcium supplements — usually around 1,000 mg per day — may reduce bone loss by 1–2%.
The effect seems to be most significant in women with low calcium intakes and during the first 2 years of taking supplements.
There doesn’t seem to be any additional benefit to taking larger doses.
A 2022 analysis of 43 studies involving over 7,000 participants under the age of 35 years found calcium supplementation improved bone mass.
In addition, several recent studies have concluded that a combination of vitamin D and calcium is more effective for osteoporosis and bone health than calcium alone.
Suggested read: 11 supplements for osteoporosis
Calcium supplements may help with fat loss
Studies have associated low calcium intake with a high body mass index (BMI) and high body fat percentage.
A 2013 study examined the effects of giving a daily 600-mg calcium supplement to college students with overweight and obesity who had shallow calcium intakes.
The study found that those given a supplement containing 600 mg of calcium and 125 international units (IUs) of vitamin D lost more body fat on a calorie-restricted diet than those who did not receive the supplement.
It’s often recommended to take vitamin D with calcium. This is because vitamin D improves the body’s absorption of calcium.
Calcium may help lower the risk of colon cancer
According to one large study, calcium from dairy products and supplements may lower the risk of colon cancer.
A 2022 analysis of 37 studies found a 6% decreased risk of colorectal cancer for every 300 mg of calcium taken daily.
Calcium supplements may help improve metabolic markers
Several studies have suggested that taking calcium supplements might improve metabolic markers, especially when taken with vitamin D.
In a 2016 study, 42 pregnant people took supplements containing calcium and vitamin D. Several of their metabolic markers improved, including blood pressure and markers of inflammation.
Other research has shown that the children of women who took calcium supplements while pregnant have lower blood pressure at age 7 than the children of mothers who did not take them.
In a recent study, more than 100 vitamin D–deficient women with overweight and polycystic ovary syndrome were given either a calcium and vitamin D supplement or a placebo pill.
Those who took the supplement showed improvements in markers of inflammation, insulin, and triglyceride levels.
However, other studies have shown no improvements in the metabolic profiles of participants who took supplements containing calcium and vitamin D while on calorie-restricted diets.
Suggested read: 9 health benefits of vitamin B6 (pyridoxine)
Summary: Studies have linked taking calcium supplements with a lower risk of colon cancer and blood pressure, as well as fat loss and increases in bone density.
Possible dangers of calcium supplements
Recent research suggests that calcium supplements may, in fact, cause some health problems. However, the evidence is mixed.
Calcium supplements may increase the risk of heart disease
Perhaps the most controversial suggestion about calcium supplements is that they may increase the risk of some types of heart disease, including heart attack and stroke.
A 2021 analysis of 13 clinical trials found that calcium supplements increased cardiovascular disease (CVD) risk by 15% in healthy postmenopausal women.
A 2020 analysis of 42 studies found that calcium from dietary sources did not raise CVD risk, but supplemental calcium did.
A 2022 study in South Korea found similar risks of CVD when a large group of subjects took calcium supplements.
More conclusive research is needed to determine the effect of calcium supplements on heart health. Some experts have suggested that taking calcium with vitamin D may neutralize the possible risks, but this needs to be studied more.
High levels of calcium may be linked to prostate cancer
High calcium levels may be linked to prostate cancer, although the research on this link is also conflicting.
In several studies, most of which were observational, researchers found that high intakes of calcium may be linked to an increased risk of prostate cancer.
However, an older randomized controlled study that gave 672 men either a calcium supplement or placebo every day for 4 years showed that participants did not have an increased risk of prostate cancer.
In fact, participants who took the supplement had fewer cases of prostate cancer.
Other research has suggested that dairy products may be the culprit. A review of 32 articles reported that consuming dairy products — but not calcium supplements — was linked to an increased risk of prostate cancer.
Suggested read: Magnesium supplements: Benefits, side effects, and dosage
Calcium supplements may increase the risk of kidney stones
There is some evidence that calcium supplements increase the risk of kidney stones.
One study on hip health gave more than 36,000 postmenopausal women either a daily supplement containing 1,000 mg of calcium and 400 IU of vitamin D or a placebo pill.
The results showed that those who took the supplement had an increased risk of kidney stones.
Furthermore, while supplement users in the study experienced an overall increase in hip bone density, they didn’t have a lower risk of hip fractures.
The risk of kidney stones appears to be linked more to supplements than to calcium derived from the diet.
According to the Institute of Medicine, consuming more than 2,000 mg of calcium per day from your diet or supplements is also linked to an increased risk of kidney stones.
Other sources say that the risk of kidney stones increases when calcium intake exceeds 1,200–1,500 mg per day.
High levels of calcium in your blood
Too much calcium in your blood leads to hypercalcemia, characterized by many negative symptoms, including stomach pain, nausea, irritability, and depression.
It can be caused by several things, including:
- experiencing dehydration
- having a thyroid condition
- taking high levels of calcium supplements
Excessive vitamin D supplements may also lead to hypercalcemia by encouraging your body to absorb more calcium from your diet.
Summary: Calcium supplements may increase the risk of heart disease and prostate cancer, although the link is unclear. Extremely high levels of calcium from any source may have adverse health effects.
Things to consider when taking calcium supplements
If you take calcium supplements, there are several factors you should be aware of.
How much calcium should you take?
Calcium supplements can help fill the gap between how much calcium you get in your diet and how much you need daily.
Remember, the recommended amount for most adults is 1,000 mg per day, increasing to 1,200 mg per day for women over 50 and men over 70.
Therefore, if you typically only get around 500 mg per day through food and need 1,000 mg per day, then you can take one 500-mg supplement daily.
However, choose your dose wisely. Taking in more calcium than you need can cause problems.
You may need to split up the dose
It’s essential to check the amount of calcium in the supplement you choose.
Your body can’t absorb large amounts of it at once. Experts recommend taking no more than 500 mg at a time in supplement form.
Medication interactions
Make sure to tell your doctor and pharmacist if you are taking calcium supplements, since they can interfere with how your body processes certain medications, including antibiotics and iron.
Calcium also competes with iron for absorption. If you are deficient in iron and need calcium supplements, try taking calcium with meals to maximize absorption and take iron supplements either 1 hour before or 2 hours after a meal.
This way, the calcium is less likely to inhibit the absorption of the iron you consume in your meal.
Dangers of too much calcium
Remember, you need only 1,000–1,200 mg of calcium each day. There’s no benefit to taking more than that. In fact, you could experience problems if you do.
Problems include constipation, hypercalcemia, calcium buildup in soft tissues, and trouble absorbing iron and zinc.
Summary: When you’re taking calcium supplements, it’s essential to consider the type, amount, and whether they may interact with other medications you take.
Different types of calcium supplements
Calcium supplements come in different forms, including tablets, capsules, chews, liquids, and powders.
One key difference between these types of supplements is the form of calcium they contain.
Suggested read: Vitamin B12 dosage: How much should you take per day?
The two primary forms are:
- calcium carbonate
- calcium citrate
These two forms differ in how much elemental calcium they contain and how well the body absorbs them. Elemental calcium refers to the amount of calcium that is present in the compound.
Calcium carbonate
This is the cheapest and most widely available form. It contains 40% elemental calcium and, therefore, usually delivers a lot of calcium in a small serving.
However, this form is more likely to cause side effects like gas, bloating, and constipation. It is recommended that calcium carbonate be taken with food for optimal absorption.
Calcium citrate
This form is more expensive. It is composed of 21% elemental calcium, meaning you may need more tablets to get the amount of calcium you need.
However, it’s more easily absorbed than calcium carbonate and can be taken with or without food.
Calcium citrate is the form recommended for people with irritable bowel syndrome.
It’s also the better choice for those with low stomach acid levels, a condition common among older adults and those taking medications for acid reflux.
Summary: The two primary forms of calcium supplements are calcium carbonate and calcium citrate. Calcium carbonate needs to be taken with food and is less effective if you have low stomach acid levels.
Food sources of calcium
It’s best to get nutrients from food rather than supplements.
However, if you feel like your calcium intake is insufficient, you may want to incorporate these foods into your diet:
- dairy, including milk, cheese, and yogurt
- canned fish with bones, such as salmon or sardines
- certain leafy greens, including collard greens, spinach, and kale
- edamame and tofu
- beans and lentils
- fortified foods and drinks
Summary: You can get all the calcium you need daily from food. Calcium-rich foods include yogurt, leafy greens, tofu, and canned fish.
Summary
Calcium pills can help people who might get osteoporosis or those who don’t eat enough calcium-rich foods.
There’s some talk about calcium pills maybe being linked to heart issues, but it’s not certain.
What we do know is that too much calcium, from any source, can increase the chances of kidney stones.
While calcium pills are okay in small amounts, getting calcium from food is the best. Try eating different foods high in calcium, even ones without dairy.
