Every cell in your bones, heart, and brain needs a steady source of calcium to work properly. Calcium supplements can help with osteoporosis, heartburn, PMS, and more. But, their use in higher doses comes with specific health risks like kidney stones. Keep reading to learn the benefits and risks of supplementing.

What is Calcium?

Vitamin is the most abundant mineral in the human body and accounts for approximately 1-2% of body fat. Each and every cell — in the bones, heart, muscles, and nervous system — want it to work.

Calcium plays essential roles in muscle contractions, blood coagulation, bone and teeth formation, and even more.

Only around 1% of total body calcium is found in the blood; the remaining 99% is stored in the bones and teeth.

ZMA Supplements: Benefits, Side Effects, and Dosage



  • Strengthens bones & prevents osteoporosis
  • May help prevent colon cancer
  • Helps maintain normal blood pressure
  • Relieves heartburn
  • May prevent pregnancy complications
  • Reduces PMS symptoms


  • Intake Has to Be balanced with other nutrients
  • Possibly dangerous in excessive amounts
  • May increase the risk of kidney stones
  • May increase the risk of prostate cancer
  • May Lead to stomach upset
  • Reduces iron absorption when taken with meals

Food Resources

The best food sources of calcium are dairy products: milk, yogurt, and cheese.

Non-dairy foods naturally Full of calcium include:

  • Canned or fresh fish with bones (sardines, sardelles, as well as salmon)
  • Beef tripe
  • Tofu (calcium-set is best)
  • Leafy greens (kale, broccoli, sprouts, bok choy, collard greens)
  • Nuts (hazelnuts, walnuts, almonds)
  • Kidney beans

A healthy and balanced diet should provide most people with the calcium they need. But some people today need more, while others cannot get enough of this mineral from food. In such circumstances, supplemental calcium may be a fantastic alternative.

As we will outline, the balanced consumption of calcium along with other nutrients is key to getting the desired benefits while reducing the danger of side effects.

Benefits of Calcium Supplements


1) Heartburn

Antacids made from calcium carbonate are effective and FDA-approved for treating mild indigestion and heartburn.

2) High Potassium Levels

Intravenous calcium gluconate can reverse heart rhythm issues induced by high potassium blood levels (hyperkalemia); it is an FDA-approved, first-line treatment.

3) Low Calcium Levels

Oral calcium supplements are effective for preventing and treating low calcium blood levels (hypocalcemia). Intravenous calcium salts are needed for acute hypocalcemia with muscle spasms.

4) Kidney Failure

The buildup of phosphate is a significant issue in some individuals with kidney failure. Oral calcium carbonate or calcium acetate is effective as a phosphate binder. Calcium acetate (PhosLo) may be a better choice, and it’s FDA-approved for this condition.

Likely Effective:

5) Osteoporosis

Calcium and vitamin D are two critical nutrients for the prevention and therapy of osteoporosis. The National Osteoporosis Foundation (NOF) recommends calcium intake of 1000 mg/day for men aged 50-70 and 1200 mg/day for girls aged 51+. Individuals who can’t fulfill their requirements from food sources are advised to take supplements.

Adequate calcium intake from foods and nutritional supplements might help prevent osteoporosis in young people and specific kinds like glucocorticoid-induced osteoporosis. That said, the evidence for calcium benefits in men is a lot poorer and requires further investigation.

Though calcium supplements are powerful individually, most experts suggest combining them together with vitamin D, which enhances calcium absorption and teaches the body to use it for bone formation.

6) PMS

Premenstrual syndrome (PMS) is extremely common and the exact causes are diverse. Low levels of vitamin D and calcium may activate PMS or contribute to the symptoms, according to a large review of 28 trials.

According to multiple studies with women suffering from PMS, calcium can relieve lots of signs such as anxiety, melancholy, exhaustion, and water retention.

Possibly Successful:

7) Bone Power


Some evidence indicates calcium can improve bone health in physically active people, such as athletes, military personnel, and manual workers.

During intense exercise, blood pH levels fall as lactate levels rise. To compensate, the body releases calcium in bones, which increases bone loss in the event the requirement for calcium is not met. Calcium supplements might be useful during these periods of intense strain on the entire body and skeletal system.

In 1 trial with 243 army employees, calcium and vitamin D improved bone density (BMD) and potency.

In yet another trial, 32 well-trained female athletes have been given a meal with ~1,350 mg calcium 90 minutes before strenuous exercise. Magnesium decreased the typical bone loss observed with prolonged high-intensity exercise.

Healthy Individuals

In a different study with 867 healthy men, calcium with vitamin D also enhanced BMD, particularly in the neck, hips, and spine. But a large review concluded that more evidence is needed before we can claim that supplementation is beneficial for many non-deficient, healthy, elderly men.

In sum, calcium supplements strengthen the bones in people at risk of deficiency. They might also shield the bones of vigorously-active healthy athletes and people.

8) esophageal Cancer Prevention

According to several inspection research, calcium supplement usage is associated with lower colon cancer rates and relapse. The majority of the trials found that calcium supplements were more successful when taken using vitamin D at the exact same time.

Calcium supplements may aid in colon cancer prevention by protecting colon cells from the harmful effects of free bile acids. Another way calcium may work is by activating a pathway called APC/beta-catenin, which becomes underactive premature in colon cancer. Vitamin D, then, helps break down bile acids and enhances DNA repair.

That stated, the studies do not prove the actual anticancer effects of calcium supplements. They’re not meant to take care of any sort of cancer.

Getting sufficient quantities of calcium from food or supplements and maintaining vitamin D levels in check might help prevent colon cancer.

9) High Blood Pressure

Adequate calcium intake may stop the onset of elevated blood pressure, according to a large review of over 3,000 individuals. Calcium intake (via food or supplements) marginally reduced blood pressure, particularly in those under 35 years old, salt-sensitive men and women, and those with low baseline calcium intake.

But a meta-analysis of eight low-fat clinical trials and 36,800 participants found no substantial consequences of a calcium-vitamin D combination on blood pressure. Further studies are needed to confirm the effectiveness of calcium supplements for blood pressure reduction.

10) Pregnancy Infection

Preeclampsia is a surprising high blood pressure during pregnancy, which often starts around the 20th week. It affects about 5 percent of elderly women and may lead to organ damage, pregnancy complications, and even death if left untreated. Adequate calcium intake is a significant part of prevention.

As reported by a huge review, calcium supplements (over 1g/day) cut the risk of preeclampsia in half.

Supplementation is very important if you do not get sufficient calcium in food. The World Health Organization urges 1.5-2 g/day for pregnant women with low dietary salt intake. Consult your doctor before supplementing to rule out any dangers or interactions.

Insufficient Evidence:

No valid clinical evidence supports the use of calcium supplements for some of those conditions in this part. Below is a summary of up-to-date animal studies, cell-based study, or low-quality clinical trials that ought to spark an additional investigation. However, you shouldn’t interpret them as supportive of any health advantage.

11) Fall Prevention

An overview study of more than 16,000 elderly people found that a combination of calcium and vitamin D supplements decreases the chance of falls. Falls are a huge hazard for the older and often lead to severe or even fatal fractures.

There’s no doubt that adequate vitamin D and calcium equilibrium is significant for bone and total health in the elderly. Together, these nutrients help maintain normal posture and muscle-nerve communication.

But some results with supplementation are less conclusive, with quite a few studies failing to find any benefit. Vitamin D appears to play a more significant role and induce positive benefits in collapse prevention. The effects of calcium, apart from vitamin D, which need further investigation.

Overall, vitamin D-calcium supplements might improve posture and lower the risk of falls in the elderly. Vitamin D seems to be more important, while the additional benefits of calcium demand further investigation.

12) Fatty Liver

Vitamin D deficiency is common in people with liver disease, which reduces calcium absorption.

In 2 trials of 120 individuals with nonalcoholic fatty liver disease, calcium and vitamin D enhanced many markers of liver damage and heart health (ALT, AST, triglycerides, and LDL cholesterol). Vitamin D alone did not improve liver health.

These findings highlight the tight synergy between calcium and vitamin D and their significance for liver, bone, and heart health. However, more research is needed to draw reliable conclusions.

Possibly Ineffective:


As stated by the largest review of evidence to-date, completed by the International Foundation for Osteoporosis, calcium supplements don’t reduce the risk of fractures. A combination with vitamin D can modestly reduce the threat, but routine supplementation isn’t suggested to get general, community-dwelling inhabitants.

In a meta-analysis of 33 clinical trials together with 51,145 participants, “using nutritional supplements that contained calcium, vitamin D, or possibly was not connected with a significant gap in the risk of hip fractures compared to placebo or no treatment”.

Weight Loss

A clinical trial of 53 people found that calcium and vitamin D improved weight loss when coupled with a restricted diet. The dosages used were 600 mg calcium and 125 IU vitamin D daily.

But a recent study of 41 studies concluded that calcium supplements don’t increase weight reduction.


According to the available evidence, calcium supplements may not assist with:

  • Heart attack threat
  • Breast cancer


According to a solid body of clinical signs, calcium supplements certainly don’t assist with:

  • Total heart failure (cardiac arrest)
  • Heart disease

Side Effects & Safety of Calcium Supplements

Calcium supplements are likely safe for an overall population, in addition to children and elderly women, at the quantities which don’t exceed the safe upper limit (more information to follow).

Potential side effects may occur due to high dosage or interactions with medications, nutritional supplements, and health ailments.

Risk of Kidney Stones

The most famous side effect of calcium supplements is a modestly higher risk of kidney stones. Data from research indicate that around 17% increased risk. The chance of this occurring may be lowered by using the calcium citrate form. Calcium citrate reduces the creation and development of the most frequent kidney stones (oxalic acid).

Gut Issues

Another relatively common side effect of calcium supplements is stomach upset. Symptoms may include constipation, bloating and cramping. Heartburn and nausea are also possible. Calcium carbonate is probably to cause these issues, as it requires stomach acid for absorption. So again, choosing the citrate form may minimize this side effect.

Reduced Nutrient Absorption

Calcium supplements may inhibit iron absorption when taken with foods. Girls have higher iron requirements than men and should take calcium supplements at least 2 hours before or after meals.

Over-supplementing calcium may come at the cost of other nutrient deficiencies. If you increase your calcium intake, You Have to Make Certain You are getting adequate amounts of:

  • Vitamin D
  • Magnesium
  • Vitamin K (especially K2)

These are significant nutrients that help calcium work optimally in the body.

Heart Health

A number of studies have found that calcium supplements increase the chance of cardiovascular disease. However, several large reviews believe the evidence too weak to draw any reliable conclusions.

A 2012 review of 16 research and above 350k people didn’t find a link between heart disease and calcium supplements.

Two more recent reviews likewise found no evidence of increased risk of cardiovascular disease, concluding that calcium consumption from all sources under 2,500 mg/day is safe.

Reviews by specialist panels including the National Osteoporosis Foundation, the American Society for Preventive Cardiology, and the International Foundation for Osteoporosis — this up view.

Prostate Cancer

Concerns are raised about high calcium consumption in men and prostate cancer risk. However, it is not possible to draw any conclusions yet.

According to a review study including more than 900k men aged 50-70 years, higher calcium intake (over 750 mg/day) raises the probability of prostate cancer.

Other studies found the probability of prostate cancer simply increase to a significant extent when calcium intake is over 2,000 mg/day.

A potential explanation is that high calcium consumption ups your vitamin D needs. Vitamin D protects cells from prostate and other cancer forms. To keep on the safe side, make sure you get adequate vitamin D if you take calcium supplements.

Safe Levels

With calcium, more is not better. Below will be the maximum daily levels of calcium you shouldn’t transcend, such as both supplements and food resources. Approximately 5 percent of women over the age of 50 years exceed these amounts by nearly 400 mg/day.

Going over the top tolerable levels for a brief while is unlikely to cause any difficulties, but doing so long-term is unsafe.

Age                              Male                                 Female                        Pregnant                          Lactating
0–6 weeks                 1,000 milligrams           1,000 mg
7–12 weeks                1,500 mg                         1,500 mg
1–8 years                   2,500 mg                         2,500 mg
9–18 years                 3,000 mg                        3,000 mg                    3,000 mg                          3,000 mg
19–50 years               2,500 milligrams          2,500 mg                     2,500 mg                          2,500 mg
51+ years                    2,000 mg                        2,000 mg

Calcium supplements are far more probably safe if you don’t exceed the recommended amounts and get sufficient amounts of other critical nutrients.

Heavy Metal Contamination

Calcium supplements may be infected with heavy metals. Analyses found lead levels above the safe limits in certain goods. The”natural sources” of calcium (dolomite, coral calcium, oyster shell) comprised the highest levels of the guide: 4-12x that of processed nutritional supplements!

Drug Interactions

Supplement-drug interactions can be dangerous and, in rare circumstances, even life-threatening. Always consult your physician before supplementing and inform them about all drugs and supplements you are using or considering.

Calcium supplements should not be taken with certain medicines, including the following:

  • Ceftriaxone: may result in life-threatening damage to the lungs and kidneys
  • Dolutegravir, Elvitegravir (HIV): calcium can reduce the effectiveness of these
  • Antacids (TUMS, Rolaids, Chooz): combining these may lead to an overdose of calcium

Calcium Supplements & Dosage


The best-researched and many frequent salts are calcium carbonate. It contains 40% elemental calcium, the highest of any kind. On the downside, its absorption rate is relatively low: only around 22 percent. It’s also the least water-soluble calcium salt, making it challenging to use in beverages.

People with low stomach acid will have trouble absorbing calcium carbonate, which requires a contaminated environment to dissolve. If you take medication for acid reflux (for example, histamine-2 blockers and proton-pump inhibitors), then you are most likely one of these.

Other forms contain calcium orotate, citrate, and hydroxyapatite salts, and coral- or oyster-derived products, to name a couple. If you’re looking for a breakdown of the pros and cons of each calcium salt, read through this informative article.

Daily Needs

Most adults need at least 1,000 mg of calcium per day. Women more than 50 years need a bit more, 1,200 mg a day. If you’re a teenager who’s pregnant or nursing, then be sure to get at least 1,300 mg calcium per day.

The amount of supplemental calcium you need is dependent upon your daily diet. If dietary intake is low, you can supplement with up to 1,000 mg/day, unless directed differently by a health care provider. Divided doses of no more than 500 mg work best.

Clinical Dosage

The below doses may not apply to you personally. If your doctor suggests with a calcium supplement, work together to find the optimal dose according to your health condition and other factors.

The average daily calcium concentrations in clinical trials were as follows:

  • Bone health: 1,000 to 1,200 milligrams
  • Colon cancer: 1,200 to 2,000 mg
  • Fatty liver disease: 500 mg
  • Blood pressure: 1,000 to 1,500 mg
  • Preeclampsia: 1,000 milligrams
  • PMS: 1,000 to 1,200 milligrams
  • Illness: 1,000 milligrams

This sets the normal calcium dose in a variety of 1,000-1,200 mg/day.


Calcium supplements may strengthen the bones, prevent high blood pressure, help with heartburn, encourage a healthy pregnancy, and much more. They are generally safe and well-tolerated in adequate amounts.

On the downside, they can lead to stomach upset and kidney stones. Conflicting evidence links their usage to heart problems and other health hazards. You can reduce or avoid most of the risks by remaining under the upper limit and getting enough of other nutrients: vitamin D, calcium, and vitamin K. Consult your doctor before supplementing.