Calcium for Runners

As a long-distance runner, you are constantly pushing yourself. Whether logging miles while training or competing in your big race, your body needs micronutrients like calcium. Are you getting enough? 

sources of calcium, like cheese, milk, tofu

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Note: This post is for informational purposes only and is not medical advice. Always speak to your provider about medical questions and issues.

When you hear about calcium, you may immediately think of bone health.

Yes, calcium is a major factor in bone structure and strength. But calcium isn’t just needed for the strength of our bones.

Calcium is an essential micronutrient that is important for many different processes in the body.

Calcium plays a role in muscle contraction—both skeletal muscle and cardiac muscle. It also helps your body secrete hormones, manage glycogen, and perform cell division. 

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This post will cover all things calcium for runners.

The benefits of calcium, where it’s found in the diet, when you should take a calcium supplement, what type is best absorbed, and how much you need. 

Let’s get started!

Importance of Calcium for Athletes

Calcium is one of the most abundant minerals in your body. It’s needed for multiple functions.

Calcium is stored in the bones and teeth. As a runner, you have even more reason to appreciate what calcium does.

Athletes and runners have a greater need for calcium for several reasons.

Firstly, running is a high-impact sport that puts stress on your bones, increasing the need for calcium. And you lose calcium through sweat, so it needs to be replaced.

It’s not an electrolyte for runners that is lost in high amounts, but we all have different needs.

electrolyte drink with lemon and lime

In addition, you need your glycogen storage system operating at top-notch so you can power through your run. 

Calcium for Bone Health

First, let’s talk about bone health.

Running is a high-impact sport that places stress on the bones.

While running may improve bone density, you don’t want to forget about calcium in the diet.

Research indicates that those who get adequate amounts of calcium are able to prevent osteoporosis, or weakening of the bones.

When your bones are weak, you are at a higher risk for stress fractures—a common overuse injury.

If you’re increasing your training volume and intensity, you’ll want to make sure you focus on recovery after a race.

Make sure to get adequate rest AND proper nutrition (check out sports nutrition for women)—with enough calcium to protect your bones.

woman grabbing ankle on running trail

Glycogen Metabolism and Calcium

When you eat carbohydrates, your body stores what doesn’t get used as glycogen.

You tap into those glycogen stores when you’ve fasted (overnight) or when you have a training session.

Runners rely on glycogen stores so there is adequate energy to perform an entire workout. You don’t want to hit the wall when running.

In terms of glycogen metabolism being related to calcium, calcium actually stimulates the breakdown of glycogen so that glucose is readily available as fuel.

Skeleton with muscle groups shown

So on top of carb loading to prepare for your big race, be sure to prioritize calcium to ensure your body is able to access that glycogen and hence, operate at its best.

You also want to restore glycogen after a run – check out these recovery drinks and best breakfasts for runners to help get those nutrients.

And let’s not forget about the heart.

Obviously, your heart is what keeps you alive. Your heart is constantly pumping necessary oxygen and nutrients to every part of your body. Calcium is involved with the contraction of your heart muscle.

Low levels of calcium in your blood may lead to dysfunction of your regular heartbeat.

Dietary Sources of Calcium

Your body tightly regulates the amount of calcium in your blood by drawing from its stored supply in the bones.

In order to protect the calcium storage in your bones, you need to consume sources of calcium.

glass of chocolate milk

Our bodies do not make calcium, so we have to get it from our diet or through supplementation.

One of the best sources of calcium is dairy products.

Foods with the highest amount of calcium are:

Plant Sources of Calcium

If you’re eating a vegetarian or vegan diet, no need to worry – there are plenty of ways to get calcium through plant sources, along with your immunity-boosting Vitamin C and superstar magnesium.

Besides fortified cereals and juice, vegetarian sources of calcium include:  

baked tofu in blue bowl

How Much Calcium Do You Need Per Day?

How much calcium you need daily is variable.

Your calcium needs depend on your age, stage of growth and development, and gender. While there isn’t a specific requirement for athletes, the frequent depletion through sweat means you have to stay on top of your calcium intake.

And if you’re a salty sweater, you may want to be more conscious of dietary (or supplemental) calcium.

Calcium contributes to your bone density, which reaches its peak at around 25-35 years old. While calcium is important to build up that bone density, you still need calcium throughout your lifetime.

According to the National Institutes of Health (NIH), the recommended dietary allowances (RDAs) for calcium are:

  • Children and adolescents 9–18 years: 1300 milligrams per day; 
  • Adults 19–50 years: 1000 milligrams per day; 
  • Men 51–70 years: 1000 milligrams per day; 
  • Women 51–70 years: 1200 milligrams per day; 
  • Adults 71 years and older: 1200 milligrams per day; 
  • Pregnant and breastfeeding women: 1000–1300 milligrams per day 

The body can only absorb ~500mg at a time, so you want to spread your calcium intake out over the day.

Calcium Supplements for Runners – Best Absorption

There are two common types of calcium: citrate and carbonate.

Calcium citrate is the best-absorbed form of calcium. It is a bit more expensive than calcium carbonate, but less likely to cause GI discomfort. 

Another thing to consider is that vitamin D is required for the absorption of calcium.

So, in order to get enough calcium, you also need vitamin D.

You can get vitamin D from the sun, supplements, fatty fish (salmon, tuna, sardines, and swordfish), cod liver oil, and fortified foods.

This salmon salad is a great way to boost calcium and Vitamin D.

Hand holding Vitamin C

There are also certain nutrients that negatively impact the absorption of calcium.

Oxalates, phosphates, sulfates, fiber, iron and fats can all reduce the absorption of calcium.

Therefore, if you take iron supplements, make sure to space them out from when you take calcium.

It’s best to get a wide variety of calcium sources in your diet to optimize calcium levels.

Best Calcium Tablets for Runners

Research reveals that it is best to get calcium from food sources.

If you are consuming a couple of servings of dairy every day and eating a diet rich in leafy greens and legumes, you likely will not need to take calcium supplements.

Only those who are at risk of low calcium levels should consider calcium supplements, but ALWAYS speak to your medical provider or doctor before doing so.

Research about calcium supplementation is inconclusive. Keep in mind that there are sometimes risks to taking supplements.

Some evidence shows that calcium supplementation can actually cause heart problems. But recent research found supplementation had no effect on heart disease.

man running in blue jacket

You may need a calcium supplement if you have been diagnosed with osteoporosis, have absorption issues (gastric bypass surgery, inflammatory bowel disease), or if you are following a vegan diet. 

Some side effects of calcium supplementation include bloating and gas.

If you are struggling to get enough calcium in your diet, talk with your health care provider about supplements. Calcium supplements are widely available.

Here are a few options:

Key Takeaways

  • Calcium is an essential micronutrient that plays a role in many different functions of the body.
  • Because running is a high-impact sport, and you lose calcium through sweat, you need to replace calcium regularly.
  • It is best to get calcium from your diet. While dairy sources of calcium may be best absorbed, there are plant sources of calcium for vegans and vegetarians.
  • Calcium supplementation is rarely necessary. Make sure you talk with your doctor before taking a calcium supplement.
  • If you do take a supplement, the body can only absorb about 500 mg at a time.


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