Calcium: What You Need to Know

Calcium is an essential nutrient that the body needs for proper functioning. It’s the most copious mineral in your body, and it’s vital for bone health. The body needs enough calcium to develop and maintain stronger bones, and about 99% of the calcium found in our bodies is in the teeth and bones.

Calcium plays a major role in cardiovascular function and muscle movement. It also helps in the transmission of messages from the brain to other parts of the body. We consume calcium from foods like dairy, fortified foods (like cereal, juice, and non-dairy milk), and green leafy vegetables. Also, you’ll find calcium in some medications, such as antacids and supplemental form. Nevertheless, it’s best to get your daily calcium intake from natural foods whenever possible.

Health Benefits

Calcium is an essential mineral that helps the body by:

  • Releasing enzymes and hormones that helps with different bodily functions
  • Help blood vessels constrict and relax
  • Helps the nerves transmit messages
  • Helps maintain strength
  • It helps teeth and bone formation

Following are some of the benefits you’ll get from calcium.

Osteoporosis And Bone Density

Eating sufficient amounts of calcium is vital for building bone and could delay or prevent bone loss. This is important for some people who are at a high risk of bone loss. Osteoporosis is a disorder characterized by fragile and porous bones and has been associated with more bone fractures.[iv]

Colon Cancer

Research shows calcium might help prevent colon cancer. For instance, one study evaluated the effect of calcium supplements on the development of adenomatous polyps and colon cancer. Researchers found that although supplementation might contribute to slight protection against the adenomatous polyps, the data wasn’t enough to warrant recommendations that it helps fight off colon cancer.[v]


Preeclampsia is a known health condition common in pregnant women. It’s characterized by protein in the urine, swelling of feet and hands, and high blood pressure. The role calcium plays in the prevention of preeclampsia has been investigated in different studies. A meta-analysis of 13 trials showed that calcium supplements help reduce risks of preterm birth, preeclampsia, and high blood pressure.[vi]


The outcome on whether calcium helps reduce risks of hypertension is mixed. Some studies found an association between intake of calcium and hypertension risk, but others found no relationship.[vii]

Heart Disease

One study found that calcium supplements profoundly affect calcium levels, which could increase calcification – a known marker for heart disease. In essence, hypercalcemia is associated with increased arterial stiffness, vascular calcification, and increased blood coagulation, all known to raise risks of cardiovascular disease.[viii]

👨 Man Nutritional Needs

  • 1 to 3 years: 700 mg per day
  • 4 to 8 years: 1000 mg per day
  • 9 to 13 years: 1,300 mg per day
  • 14 to 18 years: 1,300 mg per day
  • 19+ years: 1,000 per day

👩 Woman Nutritional Needs

  • 1 to 3 years: 700 mg per day
  • 4 to 8 years: 1000 mg per day
  • 9 to 13 years: 1,300 mg per day
  • 14 to 18 years: 1,300 mg per day
  • 19+ years: 1,000 per day

Calcium Deficiency

Long-term calcium deficiency could lead to osteoporosis (brittle bones), alterations in the brain, cataracts, and dental changes. Calcium deficiency might not cause any early symptoms. It’s usually mild but can become life-threatening if not treated. Following are the health problems, which might result from calcium deficiency.

Muscle Problems

An individual with calcium deficiency might experience:

  • Pain in the arms and thighs when moving or walking
  • Spasms, cramps, and muscle aches
  • Tingling and numbness in the legs, feet, arms, and hands.

The symptoms might come and go but never disappear completely.[i]

Extreme Fatigue

Low calcium levels could cause severe fatigue that involves lack of energy and overall sluggish feelings. It might also result in insomnia.[ii] Fatigue associated with calcium deficiency might also involve brain fog, dizziness, and lightheadedness – mainly characterized by confusion, forgetfulness, and focus.

Skin And Nail Symptoms

Long-term calcium deficiency might cause:

  • Skin inflammation or eczema that might lead to dry or itchy patches
  • Alopecia causes the hair to fall out
  • Coarse hair
  • Dry, brittle, or broken nails
  • Dry skin
  • Psoriasis [iii]

Osteoporosis And Osteopenia

Much of the body’s calcium is stored in the bones; they need such high levels to remain strong. When the calcium levels in the bones drop, the body could divert some calcium from the bones, which makes them more brittle and susceptible to injury. Long-term lack of calcium might cause osteopenia, a decrease in the bone’s mineral density.

Possible Side Effects

Some people experience gastrointestinal symptoms such as gas, constipation, or bloating when taking calcium supplements. Calcium’s Tolerable Upper Intake Level, defined as the biggest amount an individual ought to consume, is capped at 2,500 every day for adults aged between 19 years and 50 years. For children aged nine years to 18 years, this number increases to 3,000 milligrams per day. For adults aged 51 years and above, the Tolerable Upper Intake Level is 2,000 milligrams per day. Studies show excessive calcium intake (over 4,000 milligrams) has been associated with numerous health risks.

Gas and Bloating

A few people who consume calcium supplements even in the recommended amounts might still experience some side effects, including constipation, gas, and bloating. It has been found that calcium carbonate has a higher chance of causing these symptoms than calcium nitrate. Taking calcium with food and spreading calcium doses throughout the day are some known efforts to reduce these symptoms.

Increased Calcium Levels

Long-term intake of calcium could cause high calcium levels in the blood, also known as hypercalcemia. Hypercalcemia might cause kidney stones, hypercalciuria, vascular calcification, and renal insufficiency.

Dosage and Preparation

The recommended amount of calcium that an individual needs varies with age. The RDA (recommended dietary allowance) for calcium in the US is 1,000 milligrams for adult females and males (men aged between 19 and 70 years and women aged between 19 and 50 years) and about 1,200 milligrams for older adults (men above 70 years of age and women over 50 years).

To boost the attainment of maximal peak bone mass, adolescents and children aged between 9 years and 18 should ingest about 1,300 milligrams every day. This could be in the form of calcium supplements.

Ways To Get Your Calcium

There are two ways through which you can get your calcium:

1. By consuming foods that contain high amounts of calcium.
2. You can get your calcium from supplements. Its recommended you get your calcium from eating foods because you also get more benefits than just taking calcium supplements which is just that, calcium.

You should consult a health professional before using calcium supplements.

Calcium-Rich Foods

Knowing the foods that are high in calcium could help know which meals and foods to eat regularly.

Dairy Foods

Before choosing any of the foods below, you should first look at the food label and choose dairy foods with a high percentage of calcium. This is because you might find huge differences in the foods calcium content, even amongst brands of the same food like bread, juice, and cheese.

  • Cheese including mozzarella cheese, parmesan, cheddar cheese, and ricotta
  • Whole milk
  • Non-fat or low-fat milk
  • Fruit, yogurt
  • Plain yogurt

Non-Dairy Foods

Getting sufficient calcium could be problematic if your children are allergic to milk or you do not use milk as a family. The following non-dairy foods may be an excellent choice for children with allergies to milk.

  • Collard greens
  • Amaranth
  • Soybeans
  • Oat milk, almond milk, and soy milk
  • Almonds
  • Bok Choy
  • Sesame seeds
  • Broccoli
  • Okra
  • Turnip greens
  • Spinach
  • Collard greens
  • Sardines
  • Rhubarb
  • Salmon

Calcium-Fortified Foods

Besides the natural calcium-rich foods (such as milk and the kefir, yogurt, and cheese made from it), some foods are fortified with calcium. These can be great options, especially if your children don’t like drinking milk or using dairy products. These include Calcium-fortified:

  • English muffins or bread
  • Instant oatmeal
  • Plant milk
  • Orange juice
  • Cereals


The two main types of supplements include calcium citrate and carbonate. Essentially, Calcium carbonate is generally available and should be taken with meals because it relies on stomach acid for proper absorption. Calcium carbonate contains about 40% of elemental calcium- the highest calcium concentration in supplement form for total absorption.

It’s more affordable and found in over-the-counter products like Rolaids and Tums. Basically, one tablet contains 200mg to 400mg of calcium. Calcium nitrate may be taken without food and is considered the best option amongst people with absorption disorders, inflammatory bowel disease, and achlorhydria. Don’t take calcium supplements when eating foods like rhubarb, spinach, and wheat bran.


What is the main benefit of taking calcium?

The body needs calcium to develop and maintain stronger bones. Your nerves, muscles, and heart also need it to function properly. Some studies show that taking calcium and vitamin D might have more benefits, such as high blood pressure and protection against diabetes and cancer.

What food is high in calcium?

Good source of calcium include:

1. Fish canned with bones like pilchards and sardines
2. Bread
3. Soy drinks
4. Green leafy vegetables like spinach, okra, and curly kale
5. Cheese and milk

What are the symptoms of lack of calcium deficiency?

Lack of calcium, also known as hypocalcemia symptoms, includes easy fracturing of bones, brittle and weak nails, muscle cramps, hallucinations, depression, numbness, muscle spams, or memory loss.

What’s calcium in food?

Calcium is essential for healthy bones and teeth. Also, it’s essential for the health and proper functioning of the muscle tissue and nerves. Excellent sources of calcium include dairy foods such as cheese, yogurt, and milk.

How do you know if you’re getting sufficient calcium?

A severe deficiency might produce symptoms like tingling and numbness in fingers, abnormal heart rhythm, and convulsions. To make sure you get sufficient calcium, eat the recommended amounts of dairy products like cheese, yogurt, and milk.

Does taking sodium affect calcium absorption?

Yes, High sodium intake might increase calcium excretion in urine. 

How can you get maximum benefits of calcium supplementation?

You should avoid taking calcium supplements when eating foods like rhubarb, spinach, and wheat bran. The type of acid found in such foods (uronic acid, oxalic acid, and phytic acid) might interfere with the absorption of calcium.



  1. [i] National Institute of Health Office of Dietary Supplements. Calcium.
  2. [ii] National Institute of Health Office of Dietary Supplements. Calcium.
  3. [iii] National Institute of Health Office of Dietary Supplements. Calcium.
  4. [iv] Reid IR. The roles of calcium and vitamin D in the prevention of osteoporosis. Endocrinol Metab Clin North Am. 27: 389-398. DOI: 10.1016/s0889-8529(05)70011-6
  5. [v] Weingarten MAMA, Zalmanovici Trestioreanu A, Yaphe J. Dietary calcium supplementation for preventing colorectal cancer and adenomatous polyps. Cochrane Database of Systematic Reviews 2008, Issue 1. Art. No.: CD003548. DOI: 10.1002/14651858.CD003548.pub4
  6. [vi] Chen M, Pan A, Malik VS, Hu FB. Effects of dairy intake on body weight and fat: a meta-analysis of randomized controlled trials. The American Journal of Clinical Nutrition. 2012;96(4):735-747. DOI:10.3945/ajcn.112.037119
  7. [vii] Williams V, Rawat A, Vignesh P, Shandilya JK, Gupta A, Singh S. Fc-gamma receptor expression profile in a North-Indian cohort of pediatric-onset systemic lupus erythematosus: An observational study. Int J Rheum Dis. 2019;22(3):449-457. doi: 10.6061/clinics/2012(07)22
  8. [viii] Reid IR, Birstow SM, Bolland MJ. Calcium and Cardiovascular Disease. Endocrinol Metab (Seoul). 2017;32(3):339-349. doi: 10.3803/EnM.2017.32.3.339