Our bones keep growing and strengthening until around our late 20s, when they are at their thickest and strongest. This is what doctors call our peak bone mass. Then by our mid-30s, our bones start to lose calcium faster than they store it – and so gradually lose their strength. This is a normal part of getting older and it happens to everyone.
The key is to make sure our bones are as strong as they can be at their peak. That’s why it’s so important to have plenty of calcium rich foods, such as dairy, in our diets in our younger years. Put simply, the more calcium that’s deposited in our bones in our first 30 years – and especially during childhood and the teenage years – the stronger our bones will be in later life and the greater the protection against osteoporosis.
IT’S TOOTH FRIENDLY
Eating a healthy diet and avoiding having sugary foods and drinks too often is important to help lower our chances of tooth decay. In particular, calcium has a vital role to play in helping to maintain normal teeth. Dairy products like milk, cheese and yogurt which are naturally calcium rich, can also be good choices to have instead of foods and drinks that contain a lot of sugar – hard cheese, for example, is sugar-free, and milk is a nutritious and tooth-friendly drink.
BEYOND BONES AND TEETH
Whilst calcium is vital for keeping our bones and teeth healthy, it also has many other important functions in the body that you probably don’t know about. Here are the other jobs in our body that calcium helps with…
Ensuring our muscles function properly: calcium sends signals from our nerves to our muscles to help them contract
It contributes to normal blood clotting: calcium helps form a protein which helps us form a blood clot. Without calcium, this protein cannot be made, and our blood cannot clot
It helps to release the energy from the food we eat by transforming energy from fats, for example, into energy molecules that reach all of our cells
It supports the delivery of messages between nerve cells
It helps form the enzymes that we need to digest our food
It assists in the process of cell division and specialisation – a process that helps our body to make cells that carry out specific or specialised functions in the body. For example, in adults, generic stem cells can be ‘specialised’ to replace damaged cells in our heart or skin.
Calcium + vitamin D
Vitamin D is the perfect partner to calcium as this vitamin helps the body to absorb the calcium from foods.
We make vitamin D in our body when skin is exposed to sunlight. But in the UK, this only happens between April and September when the sun’s rays are the right strength to do this. Between October and March our bodies can’t make enough vitamin D from sunlight so we need to rely on getting it from our diet.
However, only a few foods naturally contain vitamin D. The richest sources available are oily fish such as mackerel, salmon, herring and sardines, liver and eggs. Some mushrooms may also be enriched with vitamin D. Other foods such as breakfast cereals, bread and yogurts may be fortified with vitamin D, too – but make sure you check the label.
Because only a few foods supply vitamin D, it’s difficult for most people to get enough from their diet alone, so the NHS advises all adults and children over the age of one to consider taking a supplement containing 10mcg vitamin D every day, especially during the Autumn and Winter. The NHS also gives specific advice on vitamin D for babies, based on whether they are being formula fed or breastfed, and recommends a daily 10mcg supplement of vitamin D all year round for some people because they may not be able to make enough from sunlight even in the Spring and Summer. These include…
People with darker skin
People who cover their skin even when outside in sunlight
People who spend a lot of time indoors, for example, those who are housebound or in a care home
WHERE TO FIND CALCIUM
Dairy products are the main food group many of us associate with calcium and with good reason. In the UK, milk, cheese and yogurt are key providers of this nutrient. For example, in teenagers and working age adults they provide slightly more than a third of the calcium in our diets. During childhood and in our more senior years, dairy products are even bigger suppliers of calcium.
Calcium in dairy products
Regular fat varieties of milk, cheese and yogurt are good sources of calcium but don’t worry if you prefer lower fat varieties. Removing some or most of the fat from milk, cheese or yogurt, doesn’t mean missing out on other nutrients, including calcium. In fact, low-fat dairy products tend to have slightly more calcium than whole milk products.
Calcium per serving
Milk (per 200ml)
1% fat milk
Cheese (per 30g)
Plain cheese spread triangle (17g)
Plain, reduced-fat cheese spread triangle (17g)
Plain cottage cheese (120g/3tbsp)
Plain, reduced-fat cottage cheese (120g /3tbsp)
1 processed cheese slice (40g)
1 processed cheese, reduced-fat slice (20g)
Plain Yogurt (per 150g)
Whole milk yogurt
Fruit Yogurt (per 150g)
Whole milk yogurt
Fromage frais (per 100g)
Virtually fat free plain
Virtually fat free fruit
Children’s fortified fruit
Calcium beyond dairy
Calcium is found in other foods, including sardines (where the bones can be eaten), fortified bread, green leafy vegetables like spinach, kale, okra, rocket and watercress, beans, lentils, nuts and seeds. Some foods such as breakfast cereals and bread are also often fortified with calcium.
Not all calcium is equal
Often the amount of calcium in a typical serving of plant foods is much lower than in a typical serving of dairy. Plus, the calcium in plants isn’t as easily absorbed and used by the body as the calcium found in dairy.
In particular, the nutrients in dairy foods are packaged together in a unique combination that lets our bodies get the absolute best from them and in a way that’s not always seen with plant foods or when calcium is added to foods to fortify them or supplied in a man-made supplement.
Nutrition experts agree it’s best to get your nutrients, including calcium, from foods. That’s because whole foods like calcium-rich milk, cheese and yogurt contain several vitamins, minerals and other components associated with promoting health. But when medical or practical reasons make it difficult to get enough calcium from foods that are naturally rich in calcium, calcium-fortified foods or calcium supplements can help fill the gap.
Dairy foods, such as milk, yogurt and cheese, are the main food source of calcium for most people in the U.S. In fact, on average, milk is the top food source of calcium, vitamin D and potassium for Americans age 2 and older. USDA determined serving sizes for milk, yogurt and cheese based on calcium content. One cup of milk or yogurt and 1 ½ ounces of natural cheese each contain about 300 mg of calcium. Milk contains nine essential nutrients, including calcium, important for bone health.
Other food sources of calcium include vegetables such as kale, broccoli and Chinese cabbage; bony fish like canned sardines and salmon (when the soft bones are eaten); and calcium-fortified foods such as breakfast cereals, fruit juices and soy beverage.
Vegetables generally contain quite a bit less calcium per serving than milk, so if you’re relying on vegetables to meet your calcium needs, you’ll need to eat a lot of them. For example, you would need to eat about 38 cups of raw kale to get the amount of calcium in three glasses of milk, as this infographic illustrates.
Plant-based alternative beverages made from soy, almond, rice, hemp and others are sometimes fortified with calcium, but in varying amounts. Reading labels is important to understand the nutrients provided in these products.
Research has shown that replacing dairy foods with other food sources of calcium within a healthy eating pattern would require a significant change in the eating habits of most Americans. In fact, you’d need 1.1 servings of fortified soy beverage or 1.2 servings of bony fish, or 2.2 servings of leafy greens, to equal the calcium in one serving of milk.
While dairy foods provide 54% of the calcium in the diets of Americans over the age of two years, milk substitutes, fish and shellfish, dark green vegetables and lettuce all provide less than 3% of the calcium in the diet. A diet modelling study verified that if everyone ate the recommended servings of dairy foods, Americans, on average, would get adequate calcium.
If you’re not getting enough calcium from the food you eat, a dietitian or health care provider may recommend a dietary supplement. According to a Calcium Fact Sheet from the Office of Dietary Supplements, the amount of calcium in supplements varies. Check the Supplement Facts label and talk to your doctor about your calcium needs and intake.