Introduction

Making up around two per cent of our entire body weight, calcium is one of the essential nutrients for our health and well-being.¹ Calcium is a mineral found throughout the body, with over 99 per cent of it stored in our bones and teeth.² Everyone needs to consume a high level of calcium in their diet in order to carry out an array of vital bodily functions, with individuals such as adolescents having even greater requirements.³ 

Although calcium is best known for keeping our teeth and bones strong and healthy, this is not its only role.⁴ Calcium helps to regulate our heartbeat, blood clotting, nerve function, and the contraction and relaxation of muscles.⁴ Therefore, not receiving enough calcium can lead to poor health and increase your risk of conditions such as osteoporosis, where your bones become weak and fragile.²

Luckily, you can maximise your calcium intake through simple food choices. There is a large variety of calcium-rich foods that can be included as part of a balanced diet, such as dairy products, fish, and leafy green vegetables.² This article provides an overview of the different sources of calcium available, and explores how they can help us to reach our recommended calcium intake.      

Recommended calcium intake

It is widely recommended that adults aged 19 and over should consume 700 mg of calcium a day.⁵ However, higher levels are recommended for adolescents who need 800 to 1,000 mg each day to support rapid bone growth during this period.5 Certain individuals also need to be extra cautious to ensure they meet their daily requirements due to being at greater risk of calcium deficiency. This includes individuals who:⁵

• Are breastfeeding
• Are postmenopausal
• Follow a dairy-free diet
• Have coeliac disease
• Have osteoporosis

Food sources containing calcium

Dairy products

Dairy products are the best-known source of calcium and are the main source for most Western countries, accounting for around two-thirds of all calcium intake.⁶ Not only are dairy products rich in calcium, but they also contain other essential nutrients, such as protein and potassium.⁶ 

The three main dairy products are:⁶

• Milk 
• Yogurt and fromage frais
• Cheese

Information from the British Nutrition Foundation.⁷

One downside to dairy products is that they contain higher levels of fat and saturated fat compared to other calcium-containing foods, so they should be consumed in moderation as part of a balanced diet.⁵ Cheese, in particular, should be limited due to most varieties being high in saturated fat, which can increase the amount of bad cholesterol in the blood.⁸ However, reduced-fat dairy products are a widely available alternative, offering roughly the same calcium content but with less fat.⁹

Green leafy vegetables

Green leafy vegetables, such as kale, spinach, and pak choi, are a great low-calorie and low-fat source of calcium. This makes them an excellent choice for those aiming to maintain a diet that is both low in calories and fat.¹⁰ In addition to their high calcium content, green leafy vegetables are high in protein, dietary fibre, and a variety of vitamins and other essential minerals.¹⁰

Compared to dairy products, green leafy vegetables provide calcium that is more easily used by the body.²

Information from Weaver et al.¹¹

Fortified foods

An alternative to foods that naturally contain high levels of calcium is fortified foods, which have calcium added during production. These foods include cereals and plant-based milk alternatives.¹² Fortified foods were introduced as a cost-effective way to address peoples’ low calcium intake, particularly in low-income groups.¹² These foods generally have a similar calcium content to dairy milk. This makes them a great source of calcium, especially for those who may be intolerant to dairy or other calcium sources.² 

Plant-based milk alternatives are becoming increasingly popular as an alternative to dairy milk in response to issues such as lactose intolerance, calorie concerns, and animal welfare.¹³ A wide variety of plant-based milk alternatives are available, including soy, oat, and rice milk.¹³  However, calcium levels may vary by manufacturer, so it is always worth checking the label to ensure you are consuming enough calcium. 

Information from NHS Oxfordshire.¹⁴

Nuts and seeds

Nuts and seeds are a nutrient dense source of calcium that can be consumed in many different forms, including whole nuts and spreads.¹⁵ Not only are nuts and seeds a good source of calcium, but they are also rich in protein, dietary fibre, vitamins, and other minerals.¹⁵ Whilst they are usually high in fat, this fat is mostly unsaturated fat, which offers protective health benefits for cardiovascular health.¹⁵ Although nuts and seeds are not a suitable calcium source for everyone, they can be easily incorporated into the diet for most as a snack or as part of a meal.¹⁵ 

Information from the International Osteoporosis Foundation.¹⁶

Fish

Certain varieties of fish are excellent sources of calcium.¹⁷ It is already recommended that everyone should consume at least two portions of fish a week, as it is a lean source of vitamins and minerals.¹⁷ One of these portions should be oily fish, such as salmon or sardines. These provide healthy omega-3 fatty acids and vitamin D, which is essential for the absorption of calcium in the body.^16,17

It is worth noting that whilst white fish can be safely consumed in greater amounts, oily fish should be enjoyed in moderation due to concerns over it containing potential pollutants that can accumulate in our bodies.¹⁷  

Information from the International Osteoporosis Foundation.¹⁶

Legumes

Legumes are a specific type of vegetable that comes in many varieties, such as beans, peas, and lentils.¹⁸ They are easy to include in our diets as they are relatively cheap, easy to cook, and can be stored for a long time.¹⁸ Legumes are a staple within the Mediterranean diet, and for good reason.¹⁸ They are packed with protein, fibre, vitamins, and minerals, including calcium, and thus offer a versatile source of nutrients.¹⁸ Further, like green leafy vegetables, legumes are essentially fat-free and have a low glycaemic index, meaning they will not cause spikes in blood sugar.¹⁸ Therefore, legumes offer a simple source of calcium that is suitable and readily accessible for most people.¹⁸ 

Information from International Osteoporosis Foundation.¹⁶

Summary

Including calcium-rich foods in our diets is crucial for maintaining good health and well-being. Meeting our daily calcium requirements not only helps prevent calcium deficiency but also protects against certain health conditions. Key sources of calcium include dairy products like milk, yoghurt, and cheese, as well as green leafy vegetables, fortified foods, nuts and seeds, fish, and legumes. Furthermore, when included as part of a balanced diet, each source can offer additional health benefits. 

Although calcium is vital for our health, it is not the only nutrient that our bodies need. Therefore, we should aim to include a range of foods within our diets to make sure that we receive all the essential nutrients, vitamins and minerals that we need. These mindful choices will not only support our nutritional needs but will allow us to lead longer, healthier, and more enjoyable lives.