Evidence-based articles written by our team of Accredited Practising Dietitians and Nutritionists.
Calcium and Bone Banking, when do we start our investment?
Key nutrients for improving your calcium intake. Is there any specific age where calcium is more important in our diet than others?
Meg O'Connor, Accredited Practising Dietitian
It is a long-understood notion that milk makes your bones strong. As a kid you hear, ‘have your glass of milk to grow your bones and make them tough.’ But as we age this concept seems to be forgotten. In today’s blog we will look at the question, ‘Is there any specific age where calcium is more important in our diet than others?’
What is Calcium
Before we look into when calcium is important in the lifecycle, it is important to learn what exactly it is. Calcium is considered to be one of the main bone-generating minerals with 99% of the body’s calcium stores residing in the skeleton. Calcium has a multitude of roles in the human body including cell adhesion, blood clotting, muscle contractions, activation of certain chemical reactions as well as playing a role in hormonal control, to name only a few. Therefore, it is no surprise that having adequate calcium in your diet can help to prevent certain conditions such as kidney stones, hypertensive disorders, osteopenia and osteoporosis, insulin resistance and obesity.
Average intake Calcium in Australia?
Given its importance, you would assume that we’d all be consuming as much as we can of this incredible nutrient. However, the 2011-12 Australian National survey which looked at calcium intake, showed the exact opposite. From this survey it was found that nearly three quarters of females (73%) and half of all males (51%) over two years of age, were not meeting their daily calcium requirements from diet alone. The average amount of calcium consumed was 865mg and 745mg for men and women over the age of two years respectively.
But why is this the case?
There are a few reasons as to why people are not meeting their daily calcium requirements. One of the reasons may be due to avoiding dairy products as a result of dietary preferences, (veganism) or other health conditions (lactose intolerance) and not replacing these sources with adequate non-dairy alternatives. Additionally, those who are struggling with a poor appetite, may find it hard to meet requirements, with their already minimal intake. Another reason may be due to a simple lack of understanding around what a serving size of calcium looks like across different food groups, and how many of these are required to meet daily targets.
What are the daily targets?
The amount of calcium that each individual needs to consume daily varies due to sex and age group. For instance, a 10-year-old boy requires 1,000 mg of calcium per day compared to a 15 year old boy who requires 1,300 mg. Similarly, women who are between 19-50 years of age require 1000 mg of Calcium per day whereas once they turn 51, this increases to 1300 mg. For men, however, only 1,000mg is required up until the age of 70 years old. You can start to see why there is confusion around how much calcium is required per day.
So, what are the consequences of not meeting targets?
As mentioned previously calcium has a crucial role in many different systems within our body. For these systems to work effectively they need a constant supply of calcium from our blood. Calcium ends up in our blood when we eat calcium rich foods. However, if a diet is lacking in calcium rich foods, the body must ensure that the blood remains rich in calcium for the body systems to work, so it pulls calcium from the bone. While this is an incredible system that ensures our body continues to function properly, it also causes the amount of calcium in our bones to decline over time. This decline in calcium has a direct effect on our bone strength and therefore as the calcium levels drop so does our overall bone strength and density. Initially this is referred to as osteopenia, however, if left untreated and allowed to decline further, it is classified as osteoporosis.
So, when is Calcium intake most important in our life span?
The short answer is every day from the day you’re born to the day you die. Why? Because what we do when we’re young will determine if and how fast one develops osteopenia and osteoporosis later in life. But what we do later in our life will equally determine this rate of development.
How Is this the case? In the first 20-30 years of our life, we have the ability to build our bone mineral density through diet and lifestyle factors. Once we hit a certain age, we cannot build anymore bone mineral density and instead we must work to maintain it and prevent it declining.
A nice way to visualise bone mineral density is to think of a bank account. Say at 30 years of age you are given $100. If you withdraw $1 out of the account every week but only replace it with 80 cents over time your bank account will see a gradual decline. If you replace the $1 with the same amount of money each time it will stay the same and the balance will not change.
This is the same for our bones. While our bones may seem relatively ‘inactive’ they are constantly undergoing remodelling or like a bank account, losing money and then regaining back that money. How much money they regain or how well they undergo remodelling relies heavily on lifestyle behaviours. One of the key lifestyle factors is diet. We want to make sure that we are constantly topping up our bones with calcium so that they stay nice and strong.
There are many risk factors which contribute to osteoporosis. These include age, sex, genetics, low body weight, extended use of steroids, early menopause, exercise and inadequate calcium and vitamin D intake to name a few. While some of these risk factors are unavoidable, inadequate calcium and vitamin D intake is something that as a dietitian we can help with.
So, what does a day of Calcium Intake Look like for someone who has dairy?
Again, this depends on age and sex. For a female aged 51 and above her intake should be 4 serves of dairy/day. This would look like 1 cup of milk in the morning, 2 slices of cheddar cheese at lunch, 3/4 cup of yogurt at afternoon tea and another cup of milk after dinner. For women under 51 they are required to have 2.5 serves of dairy per day which could be 1 cup of milk at breakfast, 3 slices of cheese at lunch and 3/4 cup yogurt in the afternoon. For men, they only require 2.5 serves from ages 19 to 70. It is not until they reach 70+ that they should be consuming 3.5 services of calcium per day.
So, what does a day of Calcium Intake Look like for someone who has doesn’t have dairy?
For a lot of people, the above may seem like a lot of dairy to consume in one day. There are also other forms of calcium in our food which also help contribute to our blood calcium levels. A single serve of calcium is also found in 100g of almonds with skin, 60g sardines in water, 1/2 cup canned pink salmon with bones or 100g firm tofu. As you can see the volume of food is a lot more for the non-dairy sources. This therefore explains why many people choose to supplement with calcium to help meet their requirements. For those who are lactose intolerant it is important to note that lactose free alternatives also contain calcium and are a great option as well.
So, what can we do now to ensure we are having enough calcium in our diet?
Planning our meals is something that is so simple but can make a massive difference. If you are used to have a similar meal pattern each day, aim to find all of the calcium sources you’re having. Measure them out and count them up. Is there enough? If there isn’t, think about some snacks you could add into between meals to meet requirements. Maybe you could have some yogurt and fruit for morning tea or some hard cheese for afternoon tea. You could also swap out your tinned tuna for pink salmon with bones or add some extra tofu into your salads.
What if diet is just not enough?
Calcium supplements may need to be taken if diet alone is not meeting your daily calcium requirements. This is something you should speak with your GP about to ensure you take the right medication for you.
Healthy Bones doesn’t stop there
Diet alone is great at helping with bone strength and rebuilding, however, there are many other lifestyle changes you can make to help keep your bones nice and strong!! Exercise is a key lifestyle change which is growing within the osteoporosis community. Exercise Physiologists and Physiotherapists are skilled in being able to tailor exercise programs to help with building bone strength.
Are your bones as strong as they could be?
Since reading this blog, hopefully your eyes have been opened to the importance of calcium across the lifecycle. Whether you’re 10 or 80 years old, calcium is equally as important!! For further information on calcium and its importance, please check out these great resources below. Seeking advice from an Accredited Practising Dietitian who will be able to do a thorough assessment of your diet.
Written by Meg O’Connor, Accredited Practising Dietitian