Calcium Gluconate vs Calcium Carbonate – Uses, Dosage, Side Effects, Differences

Calcium is the fifth most abundant element in the body and is an essential activator in numerous enzymatic reactions. It is also important to many physiologic processes, including:

  • blood coagulation;
  • respiration;
  • renal function;
  • smooth and skeletal muscles;
  • contraction of the cardiac muscle;
  • transmission of nerve impulses;
  • cell membranes and capillary permeability;
  • muscular and skeletal systems;
  • maintenance of the functional integrity of the nervous system.

A long-term calcium deficiency can lead to cataracts, dental changes, osteoporosis, and alterations in the brain.

It is best to get your calcium from the food you eat, however, many people take calcium supplements to boost their calcium levels.

Here is a comparison between calcium gluconate and calcium carbonate, two forms of calcium:

Calcium Gluconate

It is the calcium salt of gluconic acid and is used to treat health issues originating from calcium deficiencies. It only contains 9 percent elemental calcium.

Uses

As a medication, this form of calcium is used by injection into a vein to treat:

  • magnesium toxicity (symptoms can include – nausea, hypotension, facial flushing, vomiting, depression, retention of urine, irregular heartbeat, and difficulty breathing);
  • high blood potassium;
  • low blood calcium;
  • during heart resuscitation to strengthen the heart muscle;
  • sudden severe stomach pain.

Note – following intravenous administration, calcium levels rise very fast, with effects lasting 30 to 60 minutes once dosing has finished.

Side Effects & Precautions

Possible side effects include:

  • a chalky taste following intravenous administration;
  • nausea;
  • tingling sensations;
  • vomiting;
  • increased urination;
  • decreased appetite;
  • increased thirst;
  • dry mouth;
  • constipation.

Note – because bradycardia (low heart rate) with arrhythmia or vasodilatation can occur when calcium is administered too quickly, IV injections should be accompanied by ECG control.

Kidney Stones

Image credit – https://commons.wikimedia.org/wiki/File:Kidney_stones_(_renal_calculi_),_%D0%91%D1%83%D0%B1%D1%80%D0%B5%D0%B6%D0%BD%D0%B8_%D0%BA%D0%B0%D0%BC%D0%B5%D1%9A%D0%B0_4.jpg

People who form calcium-containing stones are commonly advised not to take this calcium supplement.

Drug Interactions

It can interfere with the effects of medications such as:

  • tetracycline (Tetracap);
  • minocycline (Dynacin);
  • doxycycline (Vibramycin);
  • digoxin (Lanoxicaps);
  • vitamin D supplements;
  • antacids.

Hypercalcemia 

Hypercalcemia is a medical condition in which the calcium level in the blood is above normal. This can:

  • interfere with how your brain and heart work;
  • create kidney stones;
  • weaken your bones.

Symptoms of a calcium overdose may include:

  • chest pain;
  • change in the heartbeat;
  • excessive thirst;
  • painful joints;
  • vomiting;
  • weakness in the muscles;
  • nausea;
  • constipation;
  • abdominal pain;
  • loss of appetite.

Calcium Carbonate

Image credit – https://www.flickr.com/photos/trekkyandy/192259180

According to the National Institutes of Health’s Office of Dietary Supplements, calcium carbonate is the most widely used form of supplemental calcium. It contains 40 percent elemental calcium.

It occurs naturally in a few mineral forms such as the impure minerals – chalk, limestone, travertine, and marble as well as the pure aragonite, calcite, and vaterite minerals. It is estimated that around 4% of the Earth’s crust is made up of calcium carbonate.

Its molar mass is 100.1 g/mol and has the chemical formula of CaCO3.

Uses

It is a dietary supplement which is used when the amount of calcium taken in the diet is not enough. Additionally, it is used as an antacid to relieve acid indigestion, heartburn (a painful burning feeling in your chest or throat), and upset stomach.

Calcium carbonate is sold as a chewable tablet, hard tablet, liquid, or capsule, and can be taken orally, 3 to 4 times per day.

It is also a food additive (E170) and is found on many grocery store shelves in products like:

  • cake mixes;
  • baking powder;
  • food coloring;
  • wine;
  • baby diapers;
  • dough;
  • dry-mix dessert mixes;
  • toothpaste.

Due to its special white color, it is one of the most widely used minerals in the plastics, paper, coatings, and paints industries.

Moreover, it is a remarkable product for raising the pH of the soil. In addition, it is used in swimming pools for countervailing acidic properties of the disinfectant and for maintaining the alkalinity of water.

Side Effects

Studies have shown that taking this supplement is not likely to cause any side effects. However, certain people may still experience side effects, such as:

  • dry mouth;
  • upset stomach;
  • metallic taste;
  • vomiting;
  • loss of appetite;
  • stomach pain;
  • increased urination;
  • dizziness;
  • constipation;
  • belching.

Drug Interactions

It may interact with the following drugs:

  • tetracycline;
  • K-Phos (potassium acid phosphate);
  • Nizoral (ketoconazole) – it is an antifungal medication that is used mainly to treat fungal infections;
  • sodium acid phosphate;
  • Terramycin (oxytetracycline);
  • sodium phosphate;
  • Arestin (minocycline);
  • Declomycin (demeclocycline) – it is a semisynthetic tetracycline antibiotic that was derived from a strain of S. aureofaciens;
  • Kayexalate (sodium polystyrene sulfonate);
  • Nimotop (nimodipine);
  • Aczone (dapsone) – it is an antibiotic which is used in combination with clofazimine and rifampicin for the treatment of leprosy;
  • Sporanox (itraconazole);
  • Sprycel (dasatinib);
  • Rescriptor (delavirdine);
  • Reyataz (atazanavir).

Pregnancy & Breastfeeding

It is not recommended that breastfeeding mothers take this calcium supplement. Therefore, let your healthcare provider know if you are breastfeeding.

It’s not clear whether his calcium supplement could harm a developing fetus. Tell your doctor if you are pregnant before taking this supplement.

Bottom Line – Calcium Gluconate vs Calcium Carbonate

Calcium gluconate is a mineral supplement which contains a small concentration of elemental calcium. Therefore, to reach desirable doses of calcium, many tablets have to be consumed.

Calcium carbonate is the least expensive and most common form of calcium. It is well tolerated and absorbed in most people when taken with a meal.

In conclusion, both calcium supplements are used to prevent or to treat calcium deficiencies. However, calcium carbonate provides higher quantities of elemental calcium and requires fewer tablets than other forms of calcium.

References

https://gut.bmj.com/content/gutjnl/8/6/592.full.pdf
https://www.sciencedirect.com/science/article/pii/S0009250913002017
https://pubs.acs.org/doi/abs/10.1021/ic8007409