There is some controversy as to whether calcium intake (particularly that of calcium supplementation) is linked to a higher coronary artery calcium score. Fundamentally, a fine balance needs to occur between calcium intake and osteoperosis risk reduction versus that of detrimental effects on the heart. As a general rule of thumb, caution must be given to regular high doses of calcium supplementation. On the other hand, dietary sources of calcium (predominantly in the form of dairy products) seem to have a protective affect on the heart.

What is the nature of a coronary artery calcium score? 

A coronary artery calcium score utilises a CT scan. It measures the amount of hardened calcium (also known as plaque) inside the walls of your arteries. At any age, a calcium score of 0 is optimal and within a normal range. Of importance, this score only relates to hardened plaque as other risk factors need to also be evaluated. 

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Why would I get a coronary artery calcium score? 

Your doctor may request this test after a Heart Health Check has been completed. A Heart Health Check is used to estimate your risk of having a heart attack or stroke in the next 5 years based on certain risk factors that you have e.g. high blood pressure or high cholesterol (especially LDL cholesterol). Following this Heart Health Check, you will be classed as high, moderate or low risk. 

However, despite promising research, a premature heart attack may occur without having any or very few risk factors. As a result, a coronary artery calcium score may be suggested so that the extent of plaque buildup in your artery walls can be assessed (which is the main precursor for a heart attack). The ideal age for this test is between 45 to70 years. It is important to also note that a coronary artery calcium score is a preventative test and is only used in patients who do not have any symptoms such as chest pain or shortness of breath. 

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Do calcium supplements impact my coronary artery calcium score? 

Greater research is needed to determine the extent of plaque buildup and heart damage, particularly after taking calcium supplements which exceed 1400mg per day. Currently, this evidence is lacking with a direct link yet to be found between the amount of calcium in the blood (as a result of calcium supplements) and resulting heart disease. 

A possible explanation is because not all of the calcium makes it to the skeleton or gets excreted in the urine, so it may build up in the soft tissues including the heart. Also, your body uses and responds to calcium differently when calcium is derived from supplements versus the diet. This may be because supplements contain calcium salts or it could be because a large dose of calcium is consumed all at once so the body is unable to process it as efficiently.

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What about calcium intake from the diet? 

It is important to note that a diet high in calcium rich foods appears to be protective for the heart. Current Australian adult calcium guidelines are as follows: 

A standard serve is equal to: 

  • 1 cup (250ml) milk 
  • ½ cup (120ml) evaporated milk 
  • 2 slices (40g) cheese e.g. cheddar
  • ½ cup (120g) ricotta cheese 
  • ¾ cup (200g) yoghurt
  • 1 cup (250ml) milk alternative e.g. soy, rice or other cereal drink with at least 100mg of added calcium per 100ml 

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What dietary changes can help to stabilise my coronary calcium score?

  • Limiting saturated fats which include processed meats, butter, ghee, coconut oil, full fat dairy products and palm oil 
  • Increasing unsaturated fats such as fish, nuts, seeds, vegetable oils and avocado 
  • Limiting excess red meat and eggs
  • Increasing fibre, especially plant sterols 
  • Following a low salt diet 

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Further reading: 

Written by 
Mary-Anne Chamoun
Mary-Anne is an Accredited Practising Dietitian and Accredited Nutritionist who has been working in a clinical setting since 2007. She has a particular interest in managing diabetes, malnutrition, IBS, inflammatory bowel disease, and weight loss.