Many people use calcium supplements because of its strengthening effects on the bones.
But the question is – do these supplements pose any health risk, like heart diseases for example? (1).
In this article, we will review the health benefits of calcium supplements, who should take them, as well as their potential risks.
Do you need calcium?
Calcium is a very important supplement. Your body requires it for building up strong bones. It is important to note that over 99% of your body's calcium is stored in your teeth and bones (2).
Calcium in the blood helps in the transmission of nerve signals as well as regulation of the contraction and dilation of blood vessels and muscles (2).
Thus, if your diet is deficient in calcium, your body will switch to the reserves in your teeth and skeleton, and this causes a weakening of your bones.
So, what’s the right amount of calcium that you should take each day?
The Institute of Medicine gives the following recommendations (2):
- Men 70 years and below: 1000mg daily
- Women 50 years and below: 1000mg daily
- Women above 50 years: 1,200mg daily
- Men over 70: 1,200mg daily
Upper limits for supplement intake have also been recommended. For adults up to 50 years of age, 2500mg cap is recommended, while 2000mg is recommended for adults above 50 years of age (2).
You can always get sufficient calcium from your diet. Foods that are rich in calcium include nuts, some leafy greens, dairy products, tofu, and beans.
On the other hand, people who do not take adequate amounts of calcium-rich foods might switch to supplements.
Who needs calcium supplements?
If your diet is deficient in calcium, your body will switch to its reserves in your bones. This will cause your bones to be brittle and weak, resulting in osteoporosis.
The risk of osteoporosis is higher in women than in men, and so many doctors advise that women should supplement with calcium, especially after they’ve reached menopause.
And so, intake of calcium supplements is most recommended for older women (2).
If your dietary intake is not enough, you can supplement it to make up for it.
People who should consider calcium supplements include:
- Vegan dieters
- People who eat high-sodium or high-protein diets, which may cause excretion of calcium in excess.
- People with health conditions like inflammatory bowel disease or Crohn’s disease.
- People who have received prolonged treatment with corticosteroids.
- Osteoporosis patients.
Health benefits of calcium supplements
Calcium supplements have a wide range of health benefits.
Calcium supplements prevent loss of bones in postmenopausal women
Bone mass in postmenopausal women is always on the decline. This is attributed to low estrogen production.
But supplements can save the day. Some studies have shown that postmenopausal women who supplement with 1000mg of calcium daily may have their bone loss reduced by 1-2% (3).
The effect of calcium on bone loss is greatest in women whose diet is deficient in calcium. The effect is also high during the first two years of supplementing.
Also, there’s no extra benefit in taking large doses (4).
Calcium supplements may enhance fat loss
Clinical research and studies have linked low calcium intake with a high percentage of body fat and high body mass index (5).
A 2016 research investigated the effects of 600mg of calcium supplement administered daily to obese and overweight college students who were deficient in calcium.
Results from the study found that supplementing with 600mg of calcium and 125 IUs of Vit D caused a drastic reduction in percentage body fat as compared to those who didn’t take the supplement (6).
Calcium supplements are best taken along with vitamin D because vitamin D enhances calcium absorption.
Calcium reduces your risk of colon cancer
A study has shown that calcium gotten from supplements and dairy products may reduce your risk of colon cancer (7).
Similar results were found in a review of ten studies (8).
Improves metabolic markers
Many studies have shown that supplementing with calcium may up metabolic markers, especially when combined with vitamin D.
In a study conducted in 2016, 42 pregnant women supplemented with calcium and vitamin D. Results from the study showed an improvement in several markers of metabolism, as well as improvements in markers of inflammation and blood pressure (9).
Other studies have shown that babies from women who supplemented with calcium while pregnant have lower blood pressure at the age of 7 compared to children whose mothers did not take any supplement (10).
Also, a recent study was conducted involving 100 women with polycystic ovary syndrome. The women were also overweight and deficient in vitamin D. In the study, the women were split into two groups – one given a vitamin D and calcium supplement, and the other given a placebo pill.
The calcium supplement group had their markers of inflammation improved. There was also an improvement in their triglyceride and insulin levels (11, 12).
Other studies, however, showed no improvements in the calcium levels of those who took vitamin D and calcium supplements (6).
Do calcium supplements have any health risks?
Results from recent studies suggest that calcium supplements may have slight health risks. But the evidence is mixed.
The risk of heart disease
One of the most controversial risks or "claims of risk" about calcium supplements is that they may increase a person's risk of stroke, or a heart attack.
Over the years, many opposing findings have been published on this subject (1, 13, 14, 15, 16, 17, 18, 19, 20).
There is a need for further research to determine what effect supplementing with calcium has on heart health.
According to experts, combining calcium with vitamin D may mitigate the risks, but there's a need for more studies on this subject (14, 15).
Increased levels may be associated with prostate cancer
An increase in calcium levels may be associated with prostate cancer. However, studies on this subject have yielded conflicting results.
In many studies (which were observational though), medical researchers discovered that intake of calcium in high amounts was linked to a higher risk of prostate cancer (21, 22, 23, 24, 25).
On the other hand, a randomized control trial that administered calcium supplements on 672 men daily for 4 years found that their risk of prostate cancer was non-existent.
It is worth noting that participants who took the supplement had a few cases of prostate cancer (21).
Other studies suggest that dairy products may be responsible. A study review found that intake of dairy products without supplementing with calcium was associated with a high risk of prostate cancer (26).
An increased risk of kidney stones
There is proof that supplementing with calcium can increase one’s risk of kidney stones.
A study investigated the effects of 1000mg of calcium on 36,000 postmenopausal women and compared them with the effect of a placebo pill.
Results from the study showed that the intake of the supplement increased the risk of kidney stones (27).
Also, subjects who used calcium supplements experienced an increase in their hip bone density, but no reduction in their risk of hip fractures.
And according to the Institute of Medicine, taking more than 2000mg of dietary calcium daily is associated with an increased risk of kidney stones (2).
Other sources opine that taking more than 1200mg of calcium daily increases the risk of kidney stones (28).
High blood calcium levels
Excess calcium leads to hypercalcemia, which has many negative symptoms, like nausea, abdominal pain, depression, and irritability.
Hypercalcemia can be caused by dehydration, excessive supplementation with calcium, and thyroid conditions.
Taking vitamin D supplements in excess can also cause hypercalcemia by enhancing calcium absorption.
Factors to consider when supplementing with calcium
If you are supplementing with calcium, there are a few factors you should consider.
How much you should supplement
Calcium supplements can bridge the gap between your dietary calcium intake and your recommended daily intake.
Note that the amount recommended for most adults is 1000mg daily and 1200mg for women above 50 for men above 70.
So, if your diet gives just 500mg, then you may have to supplement with an extra 500mg per day (28).
But you must take care while choosing your dose. Taking calcium supplements in excess can cause some problems (29).
Splitting up the dose may be required
You must check how much calcium you’re supplementing.
Your body has a limit to the amount it can absorb at a time. Experts recommend that you don’t take more than 500mg at a time (1).
Calcium may interact with other medications
Ensure that you inform your doctor and your pharmacist if you’re supplementing with calcium as they can interfere with some medications, such as iron and antibiotics.
It is also worthy of note that calcium competes with iron, magnesium, and zinc for absorption. If you don't have these minerals or are deficient in them, try supplementing between meals (30).
By so doing, there'll be less likelihood of calcium inhibiting the absorption of your dietary iron, magnesium, and zinc.
Types of calcium supplement
They occur in different forms – capsules, tablets, powders, liquids, and chews.
What differentiates these supplements from the other is the form of calcium present in them.
The major types of calcium supplement are:
- Calcium citrate and
- Calcium supplement
They differ in the amount of elemental calcium they contain and their ease of absorption.
It is expensive. It contains 21% elemental calcium, which means that you may have to increase the number of calcium tablets that you take to get the recommended daily intake.
However, the body absorbs it faster and you can take with food or without food.
Calcium citrate is recommended for patients with the irritable syndrome.
It is also great for those whose stomach acid is on the low (30).
It is cheaper than calcium carbonate and widely available. It has a 40% elemental calcium level in it and you can get much in a small serving.
However, calcium carbonate is associated with some side effects, like bloating, constipation, and gas. Calcium carbonate should not be taken without food to ensure proper absorption (30).
Calcium supplementation is helpful for people at risk of osteoporosis, as well as those whose diet is deficient in calcium.
Supplementation with calcium is fine when taken in small doses, but the best way is to take it from your natural foods. Enrich your diet with calcium foods like:
- Lentils and beans
- Fortified drinks and foods
- Tofu and edamame
- Canned fish like sardines or salmon