Calcium For Runners: How Much You Need And The Best Sources

Calcium might not receive as much attention from runners as carbohydrates, protein or iron, but it is an important part of a healthy diet and particularly important for maintaining healthy bones. It also contributes to normal muscle and nerve function, so its role extends well beyond simply keeping your skeleton strong.

For runners, bone health matters because every run places repeated forces through the body. Running itself can help support healthy bones, but those bones also need the right nutritional support. Calcium is an important part of that, alongside vitamin D, sufficient energy intake and an overall balanced diet.

Why Is Calcium Important For Runners?

Most of the calcium in your body is stored in your bones and teeth. Bone is living tissue that is continually changing throughout your life, and calcium is one of the minerals needed to maintain normal bone structure.

Calcium also helps muscles function normally and is involved in nerve signalling. These are essential processes for everyone rather than benefits that are unique to runners, but they explain why maintaining an adequate calcium intake is important when you are regularly asking your body to train and recover.

Eating more calcium will not make you faster or immediately make your bones stronger. The aim is to consistently consume enough to meet your body's requirements as part of a diet that supports your overall health and training.

Running And Bone Health

Running is a weight bearing activity and the forces generated during running can provide a useful stimulus for bone. However, being a runner does not make you immune to bone problems, and bone stress injuries are an important consideration for anyone regularly increasing the demands placed on their body.

A bone stress injury develops when repeated loading causes microscopic bone damage faster than the body can repair it. These injuries exist on a continuum and can progress from an early bone stress reaction to a stress fracture if the affected bone continues to be overloaded.

Nutrition is only one part of the picture. Training load, recovery, previous injuries and other individual factors can all contribute to bone stress injury risk. Adequate calcium is important for bone health, but simply consuming more calcium cannot compensate for inappropriate training or inadequate overall nutrition.

How Much Calcium Do Runners Need?

For most healthy UK adults, the recommended calcium intake is 700 mg per day. Running does not automatically mean that you need a higher calcium intake, and most runners should be able to obtain sufficient calcium from a varied diet.

Requirements vary at different stages of life. Children and teenagers have different calcium requirements as their skeleton develops, while some older adults and people with particular medical conditions may also be advised to consume more. This is one reason it is better to follow guidance appropriate to you rather than assuming that every runner should aim for the same amount.

For most adult recreational runners, the useful question is therefore not how much extra calcium you need because you run. It is whether your normal diet is consistently providing enough calcium in the first place.

The Best Sources Of Calcium For Runners

Milk, yoghurt and cheese are useful sources of calcium and can make it relatively straightforward to meet your daily requirements. As an example, the British Dietetic Association lists around 240 mg of calcium in 200 ml of cows' milk and around 240 mg in a 150 g serving of plain yoghurt.

There are plenty of other sources. Calcium fortified plant drinks and yoghurt alternatives can provide amounts comparable with dairy products, while tofu can be a particularly useful source when it has been set using calcium. Sardines and pilchards where you eat the bones are another good option, and bread also contributes calcium to the UK diet.

Some green vegetables can contribute too. Kale, broccoli and other low oxalate green vegetables can provide calcium that the body can absorb relatively well. Spinach is different because, although it contains calcium, its high oxalate content reduces calcium absorption, so it should not be relied upon as a major calcium source.

Read more about the best vegetables for runnersa here.

Calcium For Vegan And Dairy Free Runners

You do not have to consume dairy products to get enough calcium, but runners following a vegan or dairy free diet may benefit from paying closer attention to where their calcium is coming from. Fortified plant drinks and yoghurt alternatives can be particularly useful because calcium is deliberately added to many of these products.

It is important to check the label because not every plant based alternative is fortified. The British Dietetic Association notes that some products, including many organic versions, may not contain added calcium. Calcium set tofu, fortified cereals and bread can provide further options alongside foods such as kale and other green vegetables.

Nuts, seeds and beans also contain calcium, but some plant foods contain substances such as oxalates or phytates that can reduce the amount absorbed. They can still contribute to a balanced diet, but it makes sense not to depend entirely on them for your calcium intake.

Broccoli provides calcium that the body can absorb relatively well

Calcium And Vitamin D

Calcium and vitamin D are closely connected because vitamin D helps the body absorb calcium. This means that looking after your bones involves thinking about both rather than concentrating entirely on calcium.

UK guidance states that adults need 10 micrograms of vitamin D per day. During spring and summer, most people should be able to make sufficient vitamin D through sunlight, but NHS guidance recommends that everyone should consider taking a daily supplement containing 10 micrograms during autumn and winter. Some people at greater risk of vitamin D deficiency may be advised to take a supplement throughout the year.

Calcium, Bone Health And RED S

One of the most important nutritional issues affecting bone health in sport is not an individual vitamin or mineral but low energy availability. This occurs when the energy available from food is insufficient to adequately support both exercise and the body's normal physiological functions.

Persistent low energy availability can contribute to Relative Energy Deficiency in Sport, usually known as RED S. Among its potential consequences are impaired bone health and changes to other physiological functions. RED S can affect both female and male athletes, so it should not be viewed solely as an issue affecting women.

This is particularly relevant when discussing calcium because a runner could be consuming calcium rich foods while still failing to eat enough overall to support their training. Calcium matters, but it cannot correct the wider consequences of consistently inadequate energy intake.

Female runners should also pay attention to persistent changes to or loss of their menstrual cycle, rather than assuming this is simply a normal consequence of training hard. Male runners can also experience the effects of low energy availability. Anyone concerned about possible RED S should seek appropriate professional advice rather than trying to solve the problem by adding individual supplements.

Calcium And Stress Fractures

Stress fractures are understandably a concern for runners because they can require a considerable period away from normal training. Maintaining an adequate calcium intake supports normal bone health, but it would be misleading to suggest that calcium alone prevents stress fractures.

Current sports medicine thinking treats bone stress injuries as multifactorial. Training and loading patterns, nutrition and individual risk factors all need to be considered rather than looking for one single cause.

If you develop persistent localised bone pain, particularly pain that worsens with running, it is sensible to stop treating it as ordinary post run soreness and have it assessed. Runners who experience repeated bone stress injuries should also seek professional advice so that possible contributing factors can be investigated properly.

Do Runners Need Calcium Supplements?

Most runners do not need to take a calcium supplement simply because they run. NHS guidance says that most healthy adults should be able to obtain the calcium they need from a varied diet containing good sources of calcium.

There are situations in which a doctor or dietitian may recommend additional calcium, including for some people with osteoporosis or medical conditions affecting calcium requirements or absorption. In those circumstances, supplementation should be based on individual needs rather than a general assumption that more calcium is better.

If you think your diet contains very little calcium, looking at the foods you regularly eat is a sensible first step. Adding appropriate calcium rich foods may be all that is required, while a registered dietitian or other healthcare professional can provide individual advice where there are particular concerns.

Read more about supplements here.

Can You Have Too Much Calcium?

Consuming more calcium than you need does not automatically produce stronger bones. This is particularly relevant to supplements, where taking large amounts without a clear reason can be unnecessary and potentially cause unwanted effects.

The NHS advises that taking more than 1,500 mg of calcium a day in supplements could lead to stomach pain and diarrhoea. This is another reason not to start taking high dose calcium supplements simply because you are training for a marathon or increasing your weekly mileage.

For most runners, concentrating on obtaining sufficient calcium from food is a much more sensible approach. If supplementation has been recommended because of a medical condition or identified deficiency, follow the advice provided by your healthcare professional.

Calcium Is Only Part Of The Picture

It is easy to focus on individual nutrients when thinking about sports nutrition, but strong bones depend on more than calcium. Vitamin D, adequate energy intake and an overall balanced diet all matter, while your training programme also needs to give your body sufficient opportunity to adapt and recover.

This is particularly important for runners who are increasing their mileage, training for longer distances or deliberately trying to lose weight while training. Cutting food intake too aggressively while increasing exercise can reduce energy availability, potentially creating a bigger problem for bone health than simply being a little short of one individual nutrient.

Calcium should therefore be viewed as one part of your overall nutrition rather than something that needs to be consumed in unusually large quantities. Getting enough consistently is what matters.

Read more about nutrition for runners here.

Final Thoughts On Calcium For Runners

Calcium is important for runners because it helps maintain healthy bones and contributes to normal muscle and nerve function. For most healthy UK adults, the recommended intake is 700 mg per day, and being a runner does not automatically increase that requirement.

Dairy products, calcium fortified plant alternatives, calcium set tofu, bread, fish with edible bones and some green vegetables can all help you meet your needs. Calcium also works alongside vitamin D, while sufficient overall energy intake is particularly important for runners trying to protect their bone health.

If you regularly suffer from bone stress injuries, have concerns about your bone health or think your diet may not provide enough calcium, professional advice is more useful than simply adding a high dose supplement. For most runners, however, a varied diet containing regular sources of calcium should provide what the body needs.