Why is calcium so important to our health?

5 reasons calcium is important

Calcium is a mineral most people have heard of and one we need during all stages of life. It helps with the functioning of our bones, muscles, heart, nervous system and chemical reactions. Having a diet that gives us enough calcium, is therefore important.

People often associate dairy with calcium, for good reason, as foods such as milk, cheese and yoghurt some of the main sources of calcium in our diet and the calcium is very well absorbed from these foods.

5 reasons calcium is important for our health

1. It is important for strengthening our bones and teeth

Calcium builds and strengthens our bones. It is a ‘bone-building’ nutrient that strengthens and builds density of bones and teeth with the help of phosphorus, magnesium and Vitamin D. Vitamin D helps your body absorb calcium. These 2 nutrients work together to protect and increase bone density.

A lack of calcium can cause bones to deteriorate resulting in Osteoporosis (porous bones). This is a disease of the bone where the density becomes low causing bones to become thin, weak and fragile. This increases risk of bone fractures. You picture the inside of a bone a little like honeycomb. A strong bone has very dense honeycomb, whilst a weak bone looks like honeycomb with large air holes in it.

Women are most at risk of developing osteoporosis later in life due to menopause. During this time the hormone oestrogen, which helps with maintaining the structure of bone, reduces. Women during and after going through menopause need to keep their calcium intake and weight bearing exercise up to strengthen their bones.

A lack of calcium can also increase tooth decay. Calcium is an important mineral needed along with phosphorus for tooth and jaw bone structure.

2.Calcium helps regulate muscle functioning

Calcium regulates muscle contraction with its involvement in nerve signalling to the muscle. The calcium in our bones acts as a storage point for maintaining calcium levels in the blood which is essential for healthy nerve and muscle functioning.

There is about 1 %, of calcium found in blood, muscle, and other tissues in the body. This plays a role in bringing about the contraction and dilation (expanding) of blood vessels, muscles and helps nerve communication.

3. Calcium is needed for the transmission of nervous system messages

Calcium helps the nervous system to transmit messages. Calcium has shown to initiate and regulate responses of central nervous tissues, which is essential for communication within the body.

4. Calcium is essential for regulating heart function

Calcium helps our heart beat. Similar to muscle functioning and the nervous system communication, calcium is important for the electrical activation and pumping/contracting during the heartbeat, to pump blood around the body.

Having too little calcium has been linked with heart failure, as without calcium our heart would struggle to beat.

5. Calcium and enzyme function and blood clotting

Calcium helps enzymes to function. In this role calcium is called a cofactor.  An enzyme is a protein that allows certain chemical reactions to take place at a much faster rate than they would occur on their own. If it wasn’t for minerals such as calcium helping enzymes to perform important chemical reactions the reactions would occur to slow for the body to function.

Many enzymes require calcium ions as a cofactor, for example the co factor calcium can aid with blood-clotting.

So how much calcium do I need?

According to the current guidelines from the Australian Guide to healthy eating, people 18 and over need between 2-4 serves of milk, yoghurt, cheese and/or alternatives a day varying between age and gender. This food group contains foods rich in calcium, so having enough serves will help you take in enough calcium.

A standard serve of this food group is around 300mg of calcium (500–600kJ):

  • 1 cup (250ml) fresh, UHT long life, reconstituted powdered milk or buttermilk
  • ½ cup (120ml) evaporated milk
  • 2 slices (40g) or 4 x 3 x 2cm cube (40g) of hard cheese, such as cheddar
  • ½ cup (120g) ricotta cheese
  • ¾ cup (200g) yoghurt
  • 1 cup (250ml) soy, rice or other cereal drink with at least 100mg of added calcium per 100ml
  • 100g almonds with skin
  • 60g sardines, canned in water
  • ½ cup (100g) canned pink salmon with bones
  • 100g firm tofu -calcium set (check the label as calcium levels vary)

What can affect calcium absorption?

Different foods and lifestyle habits can affect your body’s ability to absorb calcium, these can include:

Increase:

  • Vitamin D (can increase the absorption of calcium) so get some sunshine and put your mushrooms on the window sill for half an hour before eating them. This will help them produce vitamin D!

Decrease:

  • Age (calcium absorption decreases with age)
  • High sodium and potassium diets (may increase excretion of calcium)
  • Alcohol (may increase excretion of calcium)
  • Caffeine- a cup of coffee a day is not a problem (may increase excretion of calcium)

My favourite ways to include calcium in my diet are …

  • Rokeby Farms Protein smoothies
  • Eating green leafy vegetables in stir fries with tofu (particularly Bok Choy and broccoli)
  • Cheese platters
  • Cauliflower and cheese
  • A warm glass of milk
  • Cheese and salad sandwich
  • Rokeby Farms Probiotic yoghurt (Filmjolk) with berries, almonds and muesli
  • A glass of blueberry Rokeby Farms Probiotic Yoghurt (Filmjolk) for afternoon tea
  • Mashing the bones in canned salmon to make patties

Simone Austin
Accredited practising Dietitian

References

https://www.betterhealth.vic.gov.au/health/healthyliving/calcium#role-of-calcium-in-the-body
https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/calcium-intake-calcium-bioavailability-and-bone-health/B05A9E75627F1C3D5710DBCD8313B929
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2621390/
https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/calcium-intake-calcium-bioavailability-and-bone-health/B05A9E75627F1C3D5710DBCD8313B929
https://pubmed.ncbi.nlm.nih.gov/1588635/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC151912/
https://www.dhsv.org.au/oral-health-advice/teeth-tips/calcium-vitamin-d-and-phosphorus
https://pubchem.ncbi.nlm.nih.gov/compound/5460341#section=Information-Sources
https://www.eatforhealth.gov.au/food-essentials/how-much-do-we-need-each-day/recommended-number-serves-adults
https://www.eatforhealth.gov.au/food-essentials/how-much-do-we-need-each-day/serve-sizes
https://www.ncbi.nlm.nih.gov/books/NBK56060/
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