When you have chronic illness, it isn’t uncommon to have problems with electrolyte imbalances. Because of that, I’ve decided to do a series that talks about what they are, how the body uses them and things that we can do to manage our electrolytes. For the next few weeks, I will make a post on Wednesday about one of the electrolytes.

Calcium is the most abundant mineral in the human body with 99% of it being within the bones and teeth. It also helps the body maintain neuro conduction. This means that calcium is essential for normal muscle movement and for your heart to function properly. Normal lab values for calcium range from 8.5 to 10.2 mg/dL.


Hypercalcemia is a condition in which the calcium level in your blood is above normal; greater than 10.2. Too much calcium in your blood can weaken your bones, create kidney stones, and interfere with how your heart and brain work. This is most often caused by disfunction of the parathyroid gland. However, there are other possible causes which include cancers, tuberculosis, sarcoidosis, familial hypocalciuric hypercalcemia, immobility and severe dehydration. Medications can also cause hypercalcemia. Lithium is the drug that causes this the most often because it stimulates the parathyroid hormone, but it can also happen with calcium based antacids. Over supplementation can also cause hypercalcemia.

Hypercalcemia does not always produce symptoms. This is often true when it is a mild case. In more severe cases, the symptoms will present based on which part of the body is being effected by the high levels of calcium and it varies between people.

  • Kidneys. Excess calcium makes your kidneys work harder to filter it. This can cause excessive thirst and frequent urination.
  • Digestive system. Hypercalcemia can cause stomach upset, nausea, vomiting and constipation.
  • Bones and muscles. In most cases, the excess calcium in your blood was leached from your bones, which weakens them. This can cause bone pain and muscle weakness.
  • Brain. Hypercalcemia can interfere with how your brain works, resulting in confusion, lethargy and fatigue. It can also cause depression.
  • Heart. Rarely, severe hypercalcemia can interfere with your heart function, causing palpitations and fainting, indications of cardiac arrhythmia, and other heart problems.

If left untreated, hypercalcemia can lead to serious consequences.

  • Osteoporosis. If your bones continue to release calcium into your blood, you can develop the bone-thinning disease osteoporosis, which could lead to bone fractures, spinal column curvature and loss of height.
  • Kidney stones. If your urine contains too much calcium, crystals might form in your kidneys. Over time, the crystals can combine to form kidney stones. Passing a stone can be extremely painful.
  • Kidney failure. Severe hypercalcemia can damage your kidneys, limiting their ability to cleanse the blood and eliminate fluid.
  • Nervous system problems. Severe hypercalcemia can lead to confusion, dementia and coma, which can be fatal.
  • Abnormal heart rhythm (arrhythmia). Hypercalcemia can affect the electrical impulses that regulate your heartbeat, causing your heart to beat irregularly.


Hypocalcemia is when you have too little calcium in your blood, less than 8.5. In most cases this is an asymptomatic problem and is only diagnosed through lab work. Even when it is asymptomatic, it comes with the risk of causing long term problems. This is one of the many reason that most primary care providers will make lab work part of the annual physical.

In more severe cases of hypocalcemia, symptoms will present. Those symptoms are primarily neurological and include: twitching, numbness, tingling, depression, memory loss, dry skin, changes in the nails, rough texture of the hair, muscle cramps, seizures, and abnormal heartbeats.

Usually, hypocalcemia happens when large amounts of calcium are put out when you urinate, or too little calcium enters your blood from your bones. This could be caused by certain genetic factors, vitamin deficiencies, or other conditions.

Some of the reasons either these things can happen include:

Hypoparathyroidism. The parathyroids are located near the thyroid gland in the back of the neck. The parathyroids make a hormone called parathyroid hormone ( PTH), which regulates the amount of calcium in your body. Hypocalcemia is when you make lower levels of PTH than you need, which causes you to also make less calcium. 

Pseudohypoparathyroidism. This is a genetic disorder where your body cannot react to PTH. This disorder causes you to make too little calcium, which sends your body into hypocalcemia.

Being born without parathyroid glands. Some people are simply born without parathyroid glands. A condition like DiGeorge syndrome — which is when you are missing a part of chromosome 22 — can also cause you to have smaller than normal parathyroid glands.

Hypomagnesemia. This is when you have an abnormally low level of magnesium in the blood. Lower amounts of magnesium in your body reduce the abilities of the PTH.

Vitamin D Deficiency. Vitamin D is a steroid that helps to maintain normal calcium levels. Lower amounts of vitamin D make your body’s calcium absorption levels drop. This usually happens if you are malnourished or do have enough sun exposure in your life.

Kidney issues. Having any sort of renal failure or kidney disease constantly drains the levels of calcium in your blood.

Calcium deficiency. If you do not consume enough calcium or have disorders that interfere with your body’s ability to absorb calcium, this can cause hypocalcemia. 

Pancreatitis. This condition refers to when your pancreas becomes inflamed. New research has found that often, the body’s protective responses to pancreatitis cause hypocalcemia. 

Certain medications. Drugs like rifampin (an antibiotic), and phenytoin and phenobarbital (anti-seizure drugs) can cause this. Additionally, medicines that fight bone cancers and other bone issues are also linked with hypocalcemia. These drugs include alendronate, ibandronate, risedronate, and zoledronic acid. 

Calcium requirements

How much calcium you need depends on your age and sex.

19-70 years1,000 mg
71 and older1,200 mg
19-50 years1,000 mg
51 and older1,200 mg

The recommended upper limit for calcium is 2,500 mg a day for adults 19 to 50. For those 51 and older, the limit is 2,000 mg a day.


Even if you eat a healthy, balanced diet, you may find it difficult to get enough calcium if you:

  • Follow a vegan diet
  • Have lactose intolerance and limit dairy products
  • Consume large amounts of protein or sodium, which can cause your body to excrete more calcium
  • Are receiving long-term treatment with corticosteroids
  • Have certain bowel or digestive diseases that decrease your ability to absorb calcium, such as inflammatory bowel disease or celiac disease

Common calcium supplements may be labeled as:

  • Calcium carbonate (40% elemental calcium)
  • Calcium citrate (21% elemental calcium)
  • Calcium gluconate (9% elemental calcium)
  • Calcium lactate (13% elemental calcium)

The two main forms of calcium supplements are carbonate and citrate. Calcium carbonate is cheapest and therefore often a good first choice.  However, it is important to keep the other options in mind as everyone is different and you may find that your body absorbs different kinds of supplements better than others. Generally, calcium supplements don’t cause people side effects. But on occasion they cause gas, constipation and bloating. In general, calcium carbonate is the most constipating. So, if you are having these problems, you may want to try a different kind. You may also want to switch to a different kind if you are having a difficult time raising your levels adequately.

Your body must be able to absorb the calcium for it to be effective. All varieties of calcium supplements are better absorbed when taken in small doses (500 mg or less) at mealtimes. Calcium citrate is absorbed equally well when taken with or without food and is a form recommended for individuals with low stomach acid (more common in people over 50 or taking acid blockers), inflammatory bowel disease or absorption disorders. Additionally, vitamin D promotes calcium absorption from the gut. If you take a vitamin D supplement, it is helpful to take these together. If you are not taking a vitamin D supplement, consider having your vitamin D level checked as it may be a factor in your low calcium level.

Calcium interacts with a bunch of other medications, effecting the way that those medications are absorbed. Because of that, it is really essential that you talk with your pharmacist about which medications you need to avoid taking at the same time as your calcium supplement. You should avoid taking calcium at the same time as taking an iron supplement as an example.

A final note on calcium supplementation is that there is some research out there to reflect that there is an increased risk for heart attacks and prostate cancer when taking high levels of calcium. This risk was seen more in those using supplements then in getting their calcium through diet. If you have other risk factors for these diseases, discuss the risks and benefits of calcium supplementation with your doctor.


Most people think of dairy products when they think of high calcium foods and that’s not wrong. Milk, yogurt and cheese are good sources of dairy. But not everyone can eat dairy. It is a common allergy, intolerance and trigger food so many people cannot use dairy as their calcium source. So, I’m going to focus my discussion here on where else you can get dairy in your diet.

  • Canned Fish are a calcium power house. One serving of sardines in oil has 569mg of calcium. One serving of canned salmon with bones has 232mg of calcium. Not to mention a lot of other great nutrients such as proteins and healthy fats. The key here is that you need to get the kinds that still have the bones and eat those bones.
  • Seeds are another nutritional power house. One serving of poppy seeds packs 127 mg of calcium. Sesame seeds 88mg calcium. Sunflower seeds 109mg calcium. These also offer proteins and healthy fats. Plus they are also rich in iron and magnesium. They also offer the added bonus of only needing a small amount to get their benefits. A serving of most seeds is only one table spoon.
  • White Beans are another good choice. One serving can offer a pretty good amount: Cannellini beans 55mg and navy beans 47mg. That may not seem like much but in that one cup of beans you’re getting about 5% of the recommended daily amount for an adult. Not the best source, but not too shabby either.
  • Almonds are another power house. At 246 mg of calcium per cup, almonds are a great snack that contain healthy fats, fiber, magnesium and vitamin E.
  • Leafy Greens are incredibly healthy, and many of them are high in calcium, including collard greens, spinach, and kale. For instance, 1 cup of cooked collard greens has 268 mg of calcium. Something to keep in mind is that spinach is high in other compounds that makes it more difficult for our bodies to absorb the calcium. Thus, of the three collard and kale greens offer the most bioavailable calcium.
  • Fortified foods like cereals can make it easier to meet your daily calcium needs. There are more and more foods being fortified with calcium all the time. While this isn’t the best option for absorption, it is something to keep in mind when looking for calcium in your diet.

Your PCP

Your Primary Care Provider (PCP) really will be your best ally when managing a supplement. They will be the person that will be ordering your monitoring lab work to make sure that your supplementation is meeting your goals. They will also be the ones that will help you make sure that you are taking the right amount of the supplement. Not to mention it is most likely going to be your PCP who is helping you manage those underlying conditions that is causing you to have to take a supplement in the first place. It is also possible that your supplements could interact with medications that you are taking. Your PCP and your pharmacist are your best allies for monitoring for these possible interactions. So it is super important to keep your doctor in the loop whenever you are adding in supplements.

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