Calcium Supplements: What’s right for you?

Beyond food, there are different ways that calcium can be supplemented to the body. Many products contain calcium in less absorbable forms, such as calcium carbonate. Chelated or citrated calcium supplements are easier for the body to use and can be taken with or without food. Chelated simply means that calcium is bonded to a protein molecule, and citrated means that calcium is bonded to a citrate molecule. Both processes enhance calcium's absorption in the intestinal tract. However, the greater size of the resulting molecules decreases the amount of calcium per capsule when compared with simple calcium carbonate.  

Let's explore the types of calcium commonly found in supplement form.  

Calcium Carbonate contains the highest concentration of elemental calcium at 40% by weight. Tablets are often smaller and fewer are needed. This also tends to be the cheapest form, and is the form in TUMS antacids.

Calcium carbonate is far from the best calcium source because it must be taken with food for proper absorption, and its alkaline nature may interfere with proper digestion, which requires acidity from stomach acid. A catch 22! Additionally, many people over the age of sixty already have reduced stomach acid which exacerbates the problem. Calcium carbonate shouldn't be taken on an empty stomach: it can cause bloating or constipation.

Calcium Citrate contains the second highest concentration of elemental calcium at 21% by weight. These tablets are often bigger, so more are needed to meet requirements. It absorbs well when taken without food and is a better choice for people on antacids or with digestive issues. 

Microcrystalline Hydroxyapatite Compound (MCHC) is a highly absorbable form of calcium. Sixty percent of your bone weight is made from a mineral complex of calcium, phosphate, and hydroxy groups known as calcium hydroxyapatite.  

MCHC is sourced from animal bones (usually cows or sheep) and contains a significant amount of calcium, along with other minerals required for proper bone formation. Some researchers believe that this is an optimal calcium form because it contains all of the other substances that naturally occur in the bone. Like most animal-derived products, it is important to ensure the quality of the supplement and the conditions under which the animals have been raised. To minimize the chance of contamination with heavy metals or disease agents, choose supplements that ensure a clean product. 

Coral Calcium is a naturally occurring calcium found complexed with magnesium oxide in a 4:1 ratio (calcium: magnesium) as well as many other minerals. Two types of coral calcium exist, fossilized and marine. Fossilized coral is farmed after it floats to the top of the ocean while marine grade is live coral that is vacuumed from the ocean floor. One should consider the ecological effect of both processes when purchasing coral calcium. Ensure that your supplement is tested for contaminants. Even after purification, coral calcium may contain minute amounts of heavy metals and should not be consumed by pregnant or nursing women. 

AlgaeCal Calcium comes from a South American algae named Algas calcareas, which is incorporated into a proprietary supplement.

Calcium Gluconate is used to prevent or treat low blood calcium levels in people who are deficient. It is often used in intravenous nutrient repletion, but you won’t find it in over the counter supplements.

How To Take Calcium Supplements 

Calcium supplements are best taken in divided doses throughout the day, because the body can only absorb a limited amount at one time, no matter how large an amount each dose contains. In optimal conditions this can be as much as 500mg, but in most of us it is considerably less. Some foods and medications can also impact calcium absorption.

Here are some tips for taking your calcium to maximize its benefits: 

● Meals: Different types of calcium vary in whether they're absorbed best with or without food. Calcium carbonate must be taken with meals. Calcium citrate and chelates can be taken on an empty stomach.

● Medications: Calcium should not be taken at the same time with certain medications, including antibiotics, iron supplements, high blood pressure medications, and fish oil. Calcium can bind to these and diminish their absorption. 

● Vitamin D: Calcium is best absorbed when taken with vitamin D and magnesium. Many supplements are produced with calcium, magnesium and vitamin D included. 

● Vitamin K: helps your calcium go to the right compartment: your bones!

Important Information & Potential Contraindications 

Calcium can interfere with the effects of calcium channel-blocking heart medications, tetracycline, thyroid hormone, some anticonvulsants and steroids. Calcium is also depleted by the use of phenobarbital and diuretics. Calcium and iron bind together and prevent the absorption of both minerals, therefore iron and calcium supplements should be taken separately. Essential fatty acids like fish oils may also bind with calcium, so they should be taken at different times of the day.