The Surprising Benefits of Calcium

When people think of the mineral calcium, bone health is usually the first thing that comes to mind — but its benefits go far beyond helping to build and maintain a strong skeletal structure. This mineral is also needed to regulate heart rhythms, aid in muscle function, regulate blood pressure and cholesterol levels, and is involved in numerous nerve signaling functions, and much more. That is why a calcium deficiency (also called hypocalcemia) can be so detrimental to health.

Research now even suggests that calcium and vitamin D together may have the ability to help protect against cancer, diabetes and cardiovascular disease too — three of the biggest threats to Americans’ health and the health of many other nations too.

Despite that it is such an important mineral, many adults and children are at risk for calcium deficiency. How do you know if you are deficient in calcium?

Calcium deficiency - Dr. Axe

Hypocalcemia symptoms can include:

  • having brittle, weak bones that are prone to fractures
  • abnormal blood clotting
  • weakness
  • delays in children’s growth and development

Aside from dairy products like milk or yogurt, this mineral can also be found in a variety of plant foods, such as:

  • leafy green vegetables, like collard greens and kale
  • almonds
  • sesame seeds
  • okra
  • a variety of beans

Including these in your diet regularly can help increase your intake, while supplements may also be beneficial for certain at-risk individuals.

What Is Calcium Deficiency?

Hypocalcemia is the medical term for calcium deficiency (or having low levels in the blood).

Calcium is the most abundant mineral in the human body, stored mostly in the bones and teeth. About 99 percent of our calcium is found inside the skeletal system and dental structures (bones and teeth), mostly in the form of calcium deposits. The other remaining 1 percent is stored throughout bodily tissue.

We all require a relatively high amount of this mineral in comparison to many other trace minerals. In fact, we are thought to have enough in our bodies to constitute 2 percent of our total body weight.

It is needed to control levels of magnesium, phosphorus and potassium in the blood, since these minerals all work together to balance one another.

What can happen if your calcium level is too low? As explained more below, symptoms can include weak bones and abnormal blood clotting.

Part of the reason that low levels can cause a range of negative symptoms is that your body pulls this nutrient from “calcium reserves” that are stored within your bones when your diet does not include enough. It does this to maintain enough calcium in blood, which is needed at all times and is crucial for ongoing blood vessel and muscle function.

When your body is forced to prioritize its use of available calcium, it uses it for nerve and muscle functions, like those that control your heartbeat, rather than for supporting your bones.

Hypocalcemia Symptoms

What are the symptoms of calcium deficiency in adults? Calcium deficiency symptoms can include:

  • Brittle, weak bones
  • Problems with proper blood clotting
  • Weakness and fatigue
  • Muscle spasms and cramps
  • Face twitching
  • Feeling numbness or “pins or needles”
  • Irritability
  • Delays in children’s growth and development
  • Heart problems involving blood pressure and a slowed heartbeat
  • Mood-related issues, including depression and confusion

What long-term issues does a calcium deficiency cause? It puts you at a greater risk for bone fractures or osteoporosis. It can also contribute to seizures and cardiovascular issues when severe.

What is a classic sign of hypocalcemia? Muscle cramps, numbness, face twitching and spasms seem to affect many people with low levels of calcium in blood. Some people also experience more anxiety, depression, anger and hallucinations.

Calcium Deficiency

Causes/Risk Factors

Each day, we lose calcium through our skin, nails, hair, sweat, urine and stool. We also cannot make it ourselves within our own bodies, so ideally every day we must replenish our bodies’ supply in order to avoid calcium deficiency.

What puts you at risk for having low calcium? The people at highest risk are children, adolescent girls and postmenopausal women.

What is the most common cause of hypocalcemia? This includes low intake from your diet and poor absorption.

Below are some of the reasons people can develop a deficiency in this mineral:

  • After infancy and childhood, calcium absorption decreases during adulthood (though it is increased during pregnancy) and continues to decrease with age. This means that adults need to consume more of this mineral since they absorb less.
  • What interferes with the absorption of calcium? If you eat lots of foods that contain “antinutrients” like phytic acid and oxalic acid, found naturally in some plants, these bind to calcium and can inhibit its absorption.
  • Consuming large amounts of protein or sodium or receiving long-term treatment with corticosteroids can also block absorption.
  • Since dairy products are one of the most common sources of calcium, people who are lactose intolerant or who do not eat dairy for ethical reasons (like vegans and some vegetarians) are also at an increased risk.
  • Low calcium and vitamin D levels often occur together, since absorption of both is connected.
  • Another theory is that the soil used to grow conventional crops that are normally rich in calcium has become depleted of minerals to a certain extent — therefore levels in foods are declining.
  • Other people who have digestive disorders that make it hard to break down and use this mineral are also at risk for calcium deficiency.


Experts believe that most adults in the U.S. — and many other developed nations too — do not get enough calcium on a daily basis. This is true despite the fact that most of these populations, including Americans and Europeans, consume plenty of dairy products.

This means that there’s evidence that having several servings of dairy products per day is not enough to prevent low calcium levels and that a varied diet that includes plenty of plants is also important.

  • According to the 2006 and 2018 National Health and Nutrition Examination Survey, the mean dietary calcium intakes for males over the age of 1 ranged from 871 to 1,266 milligrams per day depending on life stage.
  • Females are estimated to consume between 748 to 968 milligrams per day on average.
  • More than 50 percent of boys and girls aged 9–13 years, girls aged 14–18 years, women aged 51–70 years, and both men and women older than 70 years are believed to suffer from calcium deficiency.
  • Overall, women are believed to be more likely to suffer from low calcium than men.

How to Treat/Prevent

How much calcium do you need in a day? To stay within the normal calcium range and avoid having low levels, most health authorities recommend 1,000 milligrams daily for adult men and women under the age of 50.

Needs increase to 1,200 milligrams daily for adults over 50. Children need between 200–700 milligrams per day depending on age, while teens need about 1,300 milligrams per day to support their growing bones.

Wondering, “how can I raise my calcium level?” Here are ways to prevent and treat calcium deficiency:

1. Eat Foods High In Calcium

Consuming the foods listed below is the best way to naturally add this mineral to your diet. (The following percentages are based on the recommended daily allowance of 1,000 milligrams for adult men and women under the age of 51.)

  1. Sardines (canned with bones included) — 1 cup: 569 milligrams (57 percent DV)
  2. Yogurt or kefir — 1 cup: 488 milligrams (49 percent DV)
  3. Raw milk plus (whey protein, made from milk) — 1 cup: 300 milligrams (30 percent DV)
  4. Cheese — 1 ounce: 202 milligrams (20 percent DV)
  5. Kale (raw) — 1 cup: 90.5 milligrams (9 percent DV)
  6. Okra (raw) — 1 cup: 81 milligrams (8 percent DV)
  7. Bok choy — 1 cup: 74 milligrams (7 percent DV)
  8. Almonds — 1 ounce: 73.9 milligrams (7 percent DV)
  9. Broccoli (raw) — 1 cup: 42.8 milligrams (4 percent DV)
  10. Watercress — 1 cup: 41 milligrams (4 percent DV)

What foods help you absorb this mineral? It’s very important to note that magnesium is key to calcium absorption.

Why do you need magnesium to absorb calcium? These two work in a very special relationship with each other in the body.

If you have a calcium deficiency or imbalance, then you also may have a magnesium deficiency. Oftentimes, a magnesium deficiency can be a precursor to later calcium issues.

The relationship between calcium and magnesium is why calcium food sources are the most effective when eaten with magnesium-rich foods.

What fruits and vegetables are high in calcium and magnesium? Some of the best are:

  • leafy greens like spinach or Swiss chard
  • almonds
  • sesame seeds
  • dairy products like raw milk or yogurt
  • fish like salmon, sardines or tuna

To maximize absorption, lightly cook leafy green vegetables and soak nuts and seeds prior to eating to decrease antinutrient content.

Is Dairy Really the Best Source?

Many studies have investigated whether or not dairy, and cow’s milk in particular, is the ideal source of calcium. Results have been mixed, with some observational studies showing that dairy has a positive effect on bone health, while others show that it has no effect or even potentially harmful effects in certain cases.

One of the reasons that dairy products are often promoted as being the best source of this mineral is because not only do dairy products contain calcium, but full-fat, grass-fed dairy foods are also a good source of  vitamin K, phosphorus and to some degree vitamin D. These nutrients are all equally important in supporting bone health as calcium is, because they work together to maintain bone mineral density.

Another positive aspect of getting this mineral from high-quality dairy products is that dairy contains protein. Although the opposite was initially thought to be true, recently many studies have found a significant positive relationship between higher protein intake and increased bone mass or density.

That said, it’s also possible to get enough calcium without consuming dairy products. Vegetarians and vegans who eat a well-rounded whole foods diet, for example, can acquire it from plant sources, including sea vegetables, beans and leafy greens.

2. Consider Calcium Supplements

If you get enough from healthy foods that you eat, which also have plenty of other nutrients to provide, then you won’t need to take a supplement. Always try to aim to get the recommended daily amount of calcium you need from foods first, and then consume supplement only if needed to make up for any serious shortfall.

Speak with your doctor about the dose that’s right for you if you’ve received a deficiency diagnosis.

Real food sources come perfectly packaged with all the enzymes, minerals, vitamins and other nutrients that the body needs to properly digest and absorb these vital nutrients.

If you are going to take supplements, which kind of calcium supplement is best? It’s most beneficial to find a high-quality, food-based supplement that includes calcium, vitamin D and magnesium (essential nutrients for calcium absorption).

Can you take magnesium and calcium together? Absolutely. In fact, many quality supplements include both to help with balance.

As mentioned above, the recommended intake of calcium is as follows:

  • 1,000 milligrams daily for adult men and women under the age of 50.
  • Needs increase to 1,200 milligrams daily for adults over 50.
  • Children need between 200–700 milligrams per day depending on age, while teens need about 1,300 milligrams per day to support their growing bones.
  • Pregnant women or breastfeeding moms need about 1,200 to 1,400 milligrams a day.


  • Calcium deficiency, also called hypocalcemia, can happen if someone doesn’t get enough calcium from the diet or doesn’t absorb calcium properly.
  • Risk factors include older age, being vegetarian/vegan, being lactose intolerant, taking corticosteroids long term, having vitamin D deficiency and having an inflammatory bowel disease that affects absorption.
  • What happens if there is not enough calcium in the body? Symptoms of hypocalcemia can include brittle, weak bones and higher risk for bone fractures or osteoporosis, problems with proper blood clotting, weakness and fatigue, muscle spasms, feeling “pins or needles,”and irritability.
  • How do you fix hypocalcemia? Some of the best sources to boost levels are raw milk, dairy products like kefir or yogurt, whey protein, almonds, leafy greens, beans, sesame seeds, sardines, and salmon.
  • Adults need at least 1,000 milligrams per day until the age of 50, then about 1,200 milligrams as they get older.
  • Which brand of calcium supplements are best? The two most popular types are calcium carbonate and calcium citrate. Citrate is considered easy to absorb and is also inexpensive. It’s most beneficial to find a high-quality supplement that includes calcium, vitamin D and magnesium (essential nutrients for calcium absorption).

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