What is calcium good for?
Role in bone health
Of course, we are all trained from an early age to associate generous dietary calcium intake with healthy bones, and while it is true that 99% of the body’s calcium is indeed found in our bones and teeth, calcium intake does not directly correlate with bone formation, as there is a whole myriad of dependencies, processes and interactions involved that incorporate the activity of many other nutrients, including magnesium, vitamin C, vitamin D, vitamin K and collagen.Role in muscle function
Aside from bone health, calcium plays an equally important role in our nervous system, assisting in the communication of signals from the brain to the rest of the body, regulating muscle contraction, and perhaps most importantly, our heartbeat.It works like this. When a nerve is targetted to stimulate a specific muscle, the body then releases calcium within the muscle which assists the proteins in performing the required contraction. When the contraction has ended and the muscle can be relaxed, the body then removes the calcium from the muscle, resetting it. And all of this can happen in the time it takes to snap your fingers.
Other areas of calcium research
Calcium is also known to play a fundamental role in blood clotting, which is a complex process that involves a broad range of chemicals.Aside from bone, blood and muscle health, emerging studies suggest that calcium, especially when paired with vitamin D, appears in other areas of the research, including work on cancer, diabetes and blood pressure.
Precautions regarding calcium supplementation
All that said, in my opinion you should only take calcium supplements if explicitly advised to do so by your trusted healthcare practitioner, as supplemental doses of calcium can cause an excess of calcium in the blood, which in turn could potentially result in calcium being deposited where it shouldn't be, such as in your artery walls. Many types of supplement are handled by our body just fine when taken in excess, but calcium supplements aren't one of them.It's actually very easy to achieve sufficient levels of calcium through diet alone, and the human body already does a miraculous job of distributing the calcium obtained through your diet precisely to where it is needed. It's advisable to not disrupt that process, unless you are absolutely certain that you know what you are doing!
When should I take calcium?
The best time to take calcium supplements can depend on the particular type of calcium. For example, calcium citrate can be taken without a meal if required, but calcium carbonate is absorbed better with the stomach's acid at mealtime. By default, or if you are not certain, you can safely take your calcium supplements with a meal.
Also, given its important role in muscle function, as well as its vital interaction with vitamin D for bone health, the best time to take calcium is early in the day, making breakfast or lunch the perfect opportunity.
What does calcium combine well with?
Calcium with boron or vitamin K, taken together, for bone and calcium handling
Vitamin K is the fat-soluble partner that helps calcium bind to bone rather than settle in soft tissue, and boron is studied for reducing how much calcium leaves your body in urine. A bone routine carrying all three is using each for a different step, and a meal with some fat suits vitamin K while the calcium and boron keep their own label doses.What should I avoid taking calcium with?
Avoid taking calcium at the same time as magnesium
While it is true that our bodies require several other vitamins and minerals in order for calcium to be properly absorbed and distributed to where it is needed, including magnesium, vitamin D and vitamin K, it is not actually necessary to take them at the same time, and magnesium is actually known to compete for absorption with calcium.Specifically, studies have found that calcium competes with magnesium for intestinal absorption and transport pathways.
Avoid taking calcium at the same time as zinc, iron or manganese
Another study demonstrated that zinc absorption was reduced by up to 50% when a calcium supplement was also taken at the same time.Another mineral that has reduced absorption when combined with calcium is manganese. In one set of studies, calcium supplementation was found to decrease manganese bioavailability in healthy adults.
It is also known that calcium can affect the absorption of iron.
Avoid taking calcium at the same time as multivitamin
While it should be avoided to take calcium together with vitamin D or magnesium, both core ingredients of any multivitamin supplement, it is also advisable to not "stack" supplements that contain calcium, as excessive calcium intake can lead to calcium being deposited in places where it doesn't belong, including your arteries.Avoid taking calcium at the same time as lactoferrin
Lactoferrin is an iron-binding protein, and a calcium tablet large enough to matter competes for the same absorption window as the iron it's holding. The pair in one sitting makes a crowded moment for both, so keep the calcium at a later meal and the lactoferrin at the one where it does its work.Gel-forming fibers keep their own sitting
Gel-forming fibers such as psyllium husk, slippery elm bark, marshmallow root and glucomannan retain water and turn into a viscous gel that slows whatever is in the gut with it, and reducing its absorption. This is usually a very minor hindrance, but it is slightly more pronounced when it comes to calcium.Avoid taking calcium at the same time as vitamin D
These two can share the day, though not the same time slot: keep a few hours between them so the calcium load stays a reasonable size. Also, while calcium and vitamin D are often recommended to be taken together, and sometimes even paired together within the same supplement, taking supplemental doses of both can lead to an excessive amount of calcium in the blood, a condition known as hypercalcemia.This can lead to an increased risk of kidney stones, or even cardiovascular issues. One study revealed that there is a significant increase in the risk of suffering a stroke when calcium supplements are taken in combination with vitamin D supplements.
Avoid taking calcium at the same time as l-lysine
L-lysine can actually increase the amount of calcium that is absorbed by the body, therefore it is recommended to avoid taking any significant amount of calcium while taking lysine supplements in order to avoid an excessive presence of calcium in the blood.What are natural sources of calcium?
If you are interested in obtaining your daily calcium through your diet, you can often find it in:
It's important to remember that some varieties of leafy greens, such as spinach and rhubarb, are extremely high in oxalates. Oxalates are naturally occurring compounds that can be found in many plants that are able to bind to calcium and impair its absorption.
Who should avoid taking calcium?
Before taking calcium supplements, check with your trusted healthcare professional if any of the following apply to you:
- Hypercalcemia
- Kidney stones
High blood calcium and kidney stones
Calcium is a mineral that has an upper intake limit, and the people who need to watch it are those with a history of high blood calcium, a parathyroid problem, or calcium-containing kidney stones. A calcium supplement on top of a diet already rich in this mineral can result in passing the upper calcium limit, so make sure you factor all sources of calcium before considering calcium supplementation.Remember to always discuss any vitamins or supplements with your trusted healthcare professional if you are suffering from any health conditions.
Possible side effects of calcium
Possible side effects from taking calcium supplements may include (but are not limited to) the following:
- Constipation
- Gas
- Kidney stones at excess
If you are experiencing negative side effects from taking calcium supplements, stop taking them immediately and reach out to your trusted healthcare professional.
Drug interactions with calcium
The medicines listed below are the ones most often named in interaction reports for calcium, but it is by no means a comprehensive list:
- Antibiotics
- Bisphosphonates
- Levothyroxine
Levothyroxine
Calcium binds levothyroxine in the gut and lowers how much of the tablet is absorbed, which is why the two are usually kept about four hours apart.Bisphosphonates
Bisphosphonates are poorly absorbed even on their own, and calcium taken at the same time can worsen that absorption even further. They are taken on an empty stomach with water and a long gap before any supplement.Antibiotics
Tetracycline and quinolone antibiotics bind calcium and lose some of their effect, so a calcium supplement is best spaced a couple of hours away from them.If you are taking any prescription drugs or medication, check with your trusted healthcare professional before taking calcium supplements.
Can I take calcium while pregnant or breastfeeding?
While calcium supplements are generally safe to take during pregnancy, the above cautions still apply, so your best option is to discuss it with your doctor, as well as checking if your prenatal multivitamin already includes calcium.
Remember to always discuss any vitamins or supplements with your trusted healthcare professional while pregnant or breastfeeding, or while attempting to conceive.
What are deficiency symptoms of calcium?
Possible signs of calcium deficiency may include (but are not limited to) the following:
- Weakened bone
- Cramps
- Tingling
Diet low in calcium does not always show on a single blood test because the skeleton donates calcium. Acute hypocalcaemia is a medical emergency.
If you are experiencing abnormal symptoms, reach out to your trusted healthcare professional as soon as possible.
Where should I store calcium?
For optimal shelf life, it is recommended to keep calcium supplements stored in the cupboard. Always make sure the bottle or container is tightly closed, and kept away from sources of light, heat and humidity.
Calcium data sources & further reading
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