Importance of Calcium [Essential Need] in Human Body

Bones and teeth comprise 99% of the total calcium in the body (1). You are not a human without bones. That is how important calcium is in the first place which is the major component of bone minerals. There are many other important body functions which makes calcium a vital need for any age groups. We cover how important calcium is for human body in this blog.

Bones give structure and strength to the human body. Calcium accounts for 1 to 2 percent of adult human body weight (2). A composite of calcium, phosphorous and Water offers strength and hardness to your bones. Stronger body has stronger bones. 

Along with bones and teeth which take up to 99% of the calcium, calcium also exists in other tissues, in extracellular fluid, blood and muscles.

Calcium in Human Body: Above and Beyond Strong Bones and Teeth

Importance of Calcium in Human Body
What are the Functions of Calcium?

Research has confirmed that calcium is involved in the following important functions.

  • Building strong bones and teeth
  • Clotting blood
  • Dilation of blood vessels, which decreases blood pressure
  • Sending and receiving nerve signals 
  • Movement, squeezing and relaxing of muscles
  • Releasing hormones and other chemicals
  • Keeping a normal heartbeat
  • Sending signals inside the human body cells from brain

All of these above functions are managed by availability of adequate amounts of calcium in the body.

Any deficiency in calcium will have impact on one or more of these above functions and your health will suffer.

The human body is always in need of calcium

  • All of us need calcium for maintenance of the bones everyday at every stages of our life processes. As you age you need more and more calcium.for your bones.
  • The children don’t grow into their full height without sufficient calcium.
  • Elderly people suffer from bone fractures and osteoporosis because of lack of normal calcium level in the body. ..

.Serum Calcium Level is Always 1% and This is Vital to Body Functions

(Serum: is an amber colored liquid that separates out when blood coagulates.)

Calcium is distributed among various tissue compartments in the human body. 

Serum calcium level of 1% is always maintained to keep the body functions up. It is a small percentage but remains tightly controlled (8.4 to 9.5 mg/dL). This control does not change either with diet or with calcium deficiency in your body. Calcium can move both into and from bone matrix.

As soon as there is a small drop in calcium below this required level, there is an immediate trigger so calcium can get into the serum from bone matrix.

This amount of calcium is “borrowed” and is given back. It’s fairly easy to realize the serum calcium concentration doesn’t speak about the calcium deficit in the body.

If you are have low level of vitamin D 3, a hormone called “parathyroid hormone” production increases. This enables mobilization of calcium from bones to serum to satisfy the need of calcium level.

An example of another tight metabolic control mechanism system in the human body would be the maintenance of a normal serum glucose range in non-diabetics.

Calcium in Liver Acts as a Versatile Secondary Messenger

Calcium regulates multiple liver functions. It help regulate metabolism of carbohydrates and bile secretion.
Choleretics are substances that increase the volume of secretion of bile from the liver as well as the amount of solids secreted.

Dysregulation of calcium signaling is a hallmark of both acute and chronic liver diseases. Recent research contemplates calcium involvement in liver regeneration 4.

Calcium Improves Diabetes Mellitus (DM)

Diabetes is a pandemic affecting the life of multiple millions of people on earth.

Such patients show characteristic potassium, magnesium, phosphate, and calcium depletion.

There are consistent results supporting the use of calcium and vitamin D supplementation to reduce the risk of DM.5

Bottom line

Calcium is a vital mineral of human body. It keeps your bones and strong and hard. It helps the brain sending signals to various parts of the body. It keeps your muscles flexible. It helps the blood vessels to move blood through out the body.

Having adequate amounts of calcium in the body for the above functions described is vital. These are the amounts recommended by Institute of Medicine (IOM) sa a guideline to meet the body requirements.

Recommended Calcium Amount from Institute of Medicine (IOM) at Different Stages of Human Life

 Life-stage group                           mg/day

Infants 0 to 6 months                     200

Infants 6 to 12 months                    260

1 to 3 years old                                 700

4 to 8 years old                               1,000

9 to 13 years old                             1,300

14 to 18 years old                           1,300

19 to 30 years old                           1,000

31 to 50 years old                           1,000

51- to 70-year-old males               1,000

51- to 70-year-old females            1,200

70 years old                                     1,200

14 to 18 years old, pregnant/lactating        1,300

19 to 50 years old, pregnant/lactating            1,000

Source: Food and Nutrition Board, Institute of Medicine, National Academy of Sciences, 2010



Anusuya Choudhury


  1. Well thanks for giving us information about the the importance and functions of calcium but please can you give me any prescription of any drug that has enough calcium content that someone with calcium deficiency can take in order to increase the calcium content in the body. And please is there any suggestion of food with calcium supplements for cows

    • Hi there,

      If someone suffers from calcium deficiency, they may also from vitamin-D deficiency. Critical nutrient Vitamin-D helps absorb calcium in our body through it hormone form, i.e. 1,25 dihydroxy vitamin D3 (calciferol). 

      Increasing vitamin D level via sunlight exposure of sun screen free skin or supplementation of it through a doctor’s prescription or consultation and inclusion of diet enriched or fortified with vitamin D3 will help calcium absorption. 

      Food recommendations: Cow milk, yoghurt, cheese, Chia seeds, lentils like moong beans, Oranges, brown rice, salmon fish, Moringa leaves, Millets like finger millet, kale, spinach and many other greens are some of the examples I can offer based on my scientific literature literature search.

      Cows are herbivores and the grass or plants they eat have a low energy density. Cows have to eat large quantities of feed to supply their energy requirements and, as a result, accumulate calcium, which enters the bloodstream and mammary glands and becomes milk (Harvard, T. H. Chan)

      Disclaimer: I am not a doctor to prescribe medicines through my blog. My article is culminated based on research from NIH/NCBI and other studies from credible sources.

      Thank you for your time and intuitive comments. I hope I have answered your questions.

  2. I see in the data that you show how important is the increasing the amount of Calcium teenagers take. And it’s reasonable because in that stage of life, bones are growing and they need that additional calcium to develop properly. I thought pregnant women that were more than 20 years old required more Calcium, but it turns out the need the same as if they were not pregnant.

    • Hi Ann,

      This is an excellent question. Yes you would think so. However the experimental data reported does not support it.

      The researchers are unclear about it. Here is a narrative from NIH.

      “In general, researchers have found that during pregnancy and lactation the mother’s body physiologically adapts to the increased calcium needs of the growing fetus and newborn without the need for increased dietary calcium (Prentice, 2000).”
      There are other articles with clinical trials to support the fact that a pregnant mother lactating don’t need additional calcium. 

      The fetus takes calcium from the mother’ bone matrix which quickly fills up. 

      I hope it answers your question.

      Thank you for your intriguing question.

  3. Hi there,

    Thank you for this excellent post; I’ve found it very interesting.

    As you said in the article, calcium is super important for the body to work at its best. I do have some questions, if you don’t mind. Are there signs of calcium deficiency in the body? If so, what are the symptoms? Do we feel pain? 

    What test should we do to see if there is a lack of calcium?

    Sorry for all these questions, but I am very curious about this:)

    Thank you for this excellent post!

    • Hi Daniella,

      Any thing you see in the blog calcium helps that becomes non fictional or lose ability to function fully in the deficiency of calcium. It is another article.

      We got to remember, Calcium is not created in our body. We got to get it from foods and supplements. The body does not absorb calcium without Vitamin D. So make sure you have that enough. 

  4. Hi Anusuya. Thank you for very interesting article. I knew before that calcium is important for our bones, but I had no idea how it affect other part of our body. I didn’t heard before its so crucial for our blood system, heart nerve system and brain, and now I realized I didn’t focus too much of having diet balanced in calcium for my family. Looking forward to use your advices and make sure that my family is getting meals with proper amount of calcium.

    • Hi Cogito,

      Calcium is more important than we think everyday and throughout our life.

      You need different amout at different Stages of life. More important one has to have vitamin d

      to absorb calcium. Starting from hair to skin, and internal signal communication and more.

  5. It’s important to have calcium on a daily basis. There are several calcium sources, and milk is not the only one but there are many plant-based ones as well. With the right nutrition, I believe that one can get enough calcium and then one can also take calcium supplements. Are there any supplements you recommend?

    • Hi Christine,

      We do not want our body to be a victim of calcium deficiency. As per your question on recommending a calcium supplement I like calcium with vitamin D as supplement. The reason being for calcium to be absorbed one needs vitamin-d. Most of us in the world is deficient on this critical nutrient for one reason or other. If you are sure of your vitamin d level as sufficient, calcium from food can work very well. In that case you ask your doctor if you should supplement your body with additional Calcium. Extra calcium can have negative health effect.

      Thank you for your time reading the post and sharing your valuable opinion.

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