At a glance......
- 1 Calcium Supplements – A Brief Guide to Common Types
- 1.1 Calcium Phosphate
- 2 Mechanism of Action of Calcium Suppliment
Calcium Supplement is a basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Calcium supplements are salts of calcium used in a number of conditions. Supplementation is generally only required when there is not enough calcium in the diet. By mouth, they are used to treat and prevent low blood calcium, osteoporosis, and rickets. By injection into a vein, they are used for low blood calcium that is resulting in muscle spasms and for high blood potassium or magnesium toxicity
Best Calcium Supplement for Proton Pump Inhibitor Patients
Chronic proton pump inhibitor (PPI) use has been linked to an increased risk of hip, wrist, and spine fractures. This is because acid suppression is associated with a reduction in calcium absorption, which can lead to decreased bone density.
By creating an environment without acid, there is a significant increase in pH that may affect intestinal absorption of calcium and result in a negative calcium balance within the body. However, a single post-hoc analysis involving patients on calcium supplements varying in solubility revealed that the relationship between solubility and absorption was weak.
This analysis showed that calcium absorption is more dependent on components of coingested foods than pH solubility. On the other hand, some data suggest that calcium absorption is significantly dependent on gastric pH.
Calcium is primarily absorbed in its ionized form in the upper small intestine. Highly acidic environments, such as the gastric environment, help promote calcium ionization from foods or salt forms. The major difference between calcium supplements tends to be the salt forms.
Calcium carbonate is an insoluble salt form, while calcium citrate is a soluble salt form. Insoluble calcium salts require a lower pH to help facilitate the release of ionized calcium from the complex. Patients taking PPIs may have issues absorbing an optimal amount of calcium from insoluble salt forms, such as calcium carbonate.
Results of a study comparing the absorption of calcium at different pHs indicated that patients in the fasting state had impaired absorption of calcium from calcium carbonate but normal absorption from calcium citrate. Calcium citrate also had a 46% greater peak-basal variation and a 94% greater change in AUC for serum calcium compared with calcium carbonate.
An additional benefit from calcium citrate use was a significant reduction in serum parathyroid hormone (PTH) levels from baseline. This informs us that the calcium absorption was significant enough to reduce PTH activity and diminish bone resorption.
Calcium carbonate may be used in patients on chronic PPIs, but it must be taken with a meal to promote acid production; however, the amount of calcium absorbed is still less than what is absorbed from calcium citrate.
Because calcium citrate is not dependent on acid or pH for absorption, it may be the preferred calcium supplement for PPI users.
Calcium citrate supplements and calcium in natural products such as cheese and milk will provide patients with greater bioavailability regardless of pH. Therefore, calcium citrate should be recommended over calcium carbonate.
If a patient cannot afford calcium citrate, however, they can use calcium carbonate as long as they are properly counseled to take it with meals (specifically breakfast) to promote better absorption.
Based on current research, no clinical evidence suggests that calcium citrate is superior to calcium carbonate in terms of preventing osteoporosis-related fractures in patients on chronic PPI therapy.
Calcium Supplements – A Brief Guide to Common Types
This type of calcium supplement is the least expensive (cheapest) and most commonly used the calcium supplement. Calcium carbonate is an alkaline-based compound found in rocks, limestone, shells of marine animals, pearls, eggshells, and snails.
It holds one of the highest concentrations of elemental calcium (35-40%). However, it is not high in bioavailability. (Bioavailability refers to the amount of calcium in the supplement that can be absorbed and assimilated by the digestive system. This makes it actually usable for cellular activity and health benefits.)
It requires the production of extra stomach acid to be absorbed so is absorbed best when taken with meals. Breakfast is the best time to take calcium carbonate because the body absorbs it best when taken with a low iron meal.
We prefer calcium citrate because it is well absorbed and tolerated by most people. It has been proven to help bone density and the citrate may help to prevent kidney stones.
Calcium citrate may also be a better calcium supplement choice for people with reduced levels of stomach acids. This is especially true with more concerned older people with bone problems. Calcium citrate is different than calcium carbonate because it has an acidic base. It does not require as much hydrochloric acid (HCl) in the stomach to be absorbed, requiring less production of natural stomach acids. This allows it to be better absorbed than the carbonate form, makes calcium citrate easily absorbed and less likely to cause abdominal discomfort
It does have less elemental calcium concentration and bioavailability. However, with the nutrients we recommended, it absorbs well and doesn’t have to be taken with meals! Calcium citrate works equally as well when taken with or without food. Thus, calcium citrate is very readily absorbable and a good choice for people with low stomach acid.
Oyster Shell, Bone Meal & Dolomite Calcium
These seem like they are a more natural form of calcium and, thus, better for you. However, oyster shell calcium is very difficult to find good quality control. They are often found to show unacceptable levels of heavy metals, including lead toxins. Minimizing lead intake is important for pregnant and nursing women, and children.
Currently, calcium supplements are not tested by a regulatory agency for lead content before they are placed on the market. It is up to the manufacturer to assure that the lead content of their calcium supplement meets the FDA standards.
In general, then, these “natural forms” of calcium should be avoided.
Calcium Phosphate, Calcium Lactate, and Calcium Gluconate are forms of calcium with a lot of “bioavailability” promotion in ads. Unfortunately, they have very low levels of actual calcium in each supplement tablet. Therefore it is necessary to take a large number of tablets to consume an adequate amount of calcium every day to reach normal calcium requirements (as well as a higher price) and the bioavailability is still not certain.
This is the form of calcium found in foods such as aged cheese and baking powder. This form is a commonly used antacid and is added to fruits to keep them firm and extend shelf life. It has a medium bioavailability in the body because it can be absorbed at various pHs. As above, Calcium Phosphate, Calcium Lactate, and Calcium Gluconate have very small percentages of elemental calcium in each supplement tablet. Therefore it is necessary to take a large numberof tablets to consume an adequate amount of calcium every day.
This is the main form of calcium coming from cow’s milk. Tooth enamel and bones are very high in calcium phosphate (although supplemental forms have not shown to be readily bioavailable). This type of calcium supplement is the least likely to cause constipation. As above, Calcium Phosphate, Calcium Lactate, and Calcium Gluconate have very small percentages of elemental calcium in each supplement tablet. Therefore it is necessary to take a large number of tablets to consume an adequate amount of calcium every day.
Calcium Citrate Malate
This is a water-soluble form of calcium. It is created by mixing the calcium salt found in citric acid with malic acid. This combination has higher levels of bioavailability than the other forms listed above because it is water-soluble. It also shows some evidence of being dissolved into cell membranes. Not a bad choice if money is a problem.
This is a very effective form of calcium supplement, created through the use of the mineral salts of orotic acid. Calcium orotates are found in small amounts in all living beings. It is a primary mineral for the creation of bones and teeth and fosters cellular communications.
Both plants and animals use orotates to create DNA and RNA. Extensive scientific research done by Hans A. Nieper, M.D. has found that orotates can penetrate cell membranes, enabling the effective delivery of the calcium ion to the inner-most layers of the cellular mitochondria and nucleus. However, with the nutrients added to the products we recommend, we can achieve better results for less money (it is expensive)! But then, the grandkids don’t need their college fund anyway.
This is generally not as easily absorbed as the citrate forms – especially if stomach HCl is low. However, they are absorbed quite readily when taken with food. There is really no good reason to get this over other alternatives.
We are sometimes asked about microcrystalline hydroxyapatite (MCHC). It is an interesting calcium-containing substance derived from animal bones that may have its merits. This is especially true for older people with very low-phosphorus diets or those who don’t get enough meat or protein (which are not problems for the average American).
As the name suggests, this type of calcium comes directly from coral. Coral calcium contains calcium carbonate. However, there are additional risks to coral calcium—unless harvested sustainably, these supplements can further endanger coral reefs. If you opt for coral calcium, make sure it is harvested from above-the-sea sources where no living coral is harmed.
Oyster Shell Calcium
Comes from nature’s sources of calcium. There are downsides to this option, though. Most of the calcium from these sources is calcium carbonate, which is not very well-absorbed.
Other forms of calcium
- Calcium D-Glucarate – promotes cellular defense (but low in calcium absorption)
- Calcium Orotate – believed to offer benefits at lower doses
- Calcium Pyruvate – offers metabolic support
- Calcium Glycinate – a chelated form of calcium, meant to support rapid absorption
- Calcium L-Threonate – derived from vitamin C, offers bone support with minimal gastric upset
- Calcium Aspartate – also a chelated form; supports bone health
- Antacids- frequently contain calcium carbonate, and are a commonly used, inexpensive calcium supplement.
How to Take Extra Calcium
Follow your provider’s advice on how much extra calcium you need.
Increase the dose of your calcium supplement slowly. Your provider may suggest that you start with 500 mg a day for a week, and then add more over time.
Try to spread the extra calcium you take over the day. DO NOT take more than 500 mg at a time. Taking calcium throughout the day will:
- Allow more calcium to be absorbed
- Cut down on side effects such as gas, bloating, and constipation
The total amount of calcium adults need every day from food and calcium supplements:
- 19 to 50 years: 1,000 mg/day
- 51 to 70 years: Men – 1,000 mg/day; Women – 1,200 mg/day
- 71 years and over: 1,200 mg/day