What Is Calcium Deficiency?


Calcium deficiency, also known as hypocalcemia, is a medical condition characterized  by an abnormally low level of calcium in your bloodstream. It occurs when the level of calcium ions in the blood falls below the normal range. Calcium is an essential mineral that plays a vital role in various physiological processes, including muscle contraction, nerve function, blood clotting, and maintaining healthy bones and teeth.

Why is calcium important for you?

Calcium is a crucial mineral in your body, found mainly in your bones but also needed in your blood. It serves vital functions, like helping your nerves work, enabling muscles to move, aiding blood clotting, and maintaining a healthy heart. When there's not enough calcium in your blood (hypocalcemia), these essential functions can be affected. Having enough calcium in your bones is also important for their strength.

If you don't get sufficient calcium from your diet, your body will take calcium from your bones to compensate, which can weaken them. Hypocalcemia occurs when calcium levels in your blood are low, not in your bones.

The levels of calcium in both your blood and bones are controlled by hormones called parathyroid hormone and calcitonin. Additionally, vitamin D is crucial for maintaining calcium levels because it helps your body absorb calcium.

Insufficient calcium levels may cause rickets in children and later in life, osteomalacia or osteoporosis could develop.1,2

Causes of calcium deficiency 

Insufficient dietary intake 

Not getting enough calcium-rich foods can result in a lack of calcium. Foods high in calcium include dairy products (milk, cheese, yoghurt), leafy green vegetables (kale, broccoli), nuts, seeds, and fortified products like certain types of tofu and orange juice.

Lack of Vitamin D 

Vitamin D is necessary for absorbing calcium in the intestines. Without enough vitamin D, your body may struggle to absorb the calcium from the food you eat, leading to low calcium levels.

Medical conditions affecting absorption

Certain health conditions can interfere with calcium absorption in the intestines. Examples include celiac disease, inflammatory bowel diseases (Crohn's disease, ulcerative colitis), and gastric bypass surgery.

Kidney disorders

The kidneys play a critical role in regulating calcium levels in the body. Any condition that affects the kidneys' function can disrupt calcium balance and lead to hypocalcemia.


This condition occurs when the parathyroid glands produce insufficient parathyroid hormone (PTH), which is responsible for maintaining calcium levels in the blood.


 Some medications can interfere with calcium levels. These may include certain diuretics, anticonvulsants, and certain treatments for cancer.


An increase in blood pH levels can cause calcium to bind with proteins and become less available for the body to use.


Low magnesium levels can affect the secretion and action of parathyroid hormone (PTH), leading to calcium imbalances.

Acute pancreatitis

Inflammation of the pancreas can cause calcium to bind with fatty acids, resulting in decreased blood calcium levels.

Chronic alcoholism

Excessive alcohol consumption can affect calcium absorption and metabolism, contributing to a deficiency.3,4

Symptoms of Calcium Deficiency 

  • Muscle cramps and spasms- Calcium plays a crucial role in muscle function, and a deficiency can lead to involuntary muscle contractions, especially in the hands, feet, or facial muscles.
  • Tingling or numbness- Low calcium levels can cause a sensation of pins and needles, often felt in the fingers, toes, or around the mouth.
  • Weak and brittle nails- Calcium is essential for nail health, and a deficiency may lead to nails becoming weak and prone to breaking.
  • Fatigue and weakness- Calcium is involved in energy production, and low levels can result in feelings of tiredness and weakness.
  • Irritability and mood changes- Calcium plays a role in regulating neurotransmitters that affect mood, and a deficiency may contribute to irritability, anxiety, or depression.
  • Osteoporosis and bone fractures- Chronic calcium deficiency can weaken bones over time, increasing the risk of fractures and osteoporosis.

It's important to note that some of these symptoms may not be specific to calcium deficiency and can be caused by other medical conditions. If you experience any of these symptoms or suspect you may have calcium deficiency, it's essential to consult a healthcare professional for proper evaluation and diagnosis.3,6

Complications of Untreated Calcium Deficiency

  • Seizures- Extremely low calcium levels can lead to seizures, which are involuntary, uncontrolled movements and behaviors.
  • Abnormal heart rhythms (arrhythmias)- Calcium is critical for the proper functioning of the heart, and low levels can lead to irregular heartbeats.
  • Tetany- Severe hypocalcemia can cause a condition called tetany, characterized by muscle twitching, muscle cramps, and spasms throughout the body.
  • Difficulty in swallowing-  Severe calcium deficiency can cause spasms of the throat muscles, making it difficult to swallow (dysphagia).

Diagnosis of Calcium Deficiency 

  • Physical examination and medical history-  Your doctor will begin by asking about your symptoms, medical history, and any risk factors that could contribute to calcium deficiency. They will inquire about your dietary habits, any existing medical conditions, and medications you are taking.
  • Blood tests to assess calcium levels - Blood Tests: The most common and definitive way to diagnose calcium deficiency is through blood tests. A sample of your blood will be taken and analyzed to measure your serum calcium levels. Normal calcium levels in the blood usually range from 8.5 to 10.2 mg/dL (2.1 to 2.6 mmol/L).
  • Identification of underlying causes (e.g., vitamin D deficiency, kidney function) 
  • Vitamin D Levels: Since vitamin D is crucial for calcium absorption, your doctor may also measure your vitamin D levels to check for any deficiencies that could be contributing to low calcium levels.
  • Parathyroid Hormone (PTH) and Calcitonin Levels: In certain cases, your doctor may order tests to assess the levels of parathyroid hormone and calcitonin, as they play a key role in calcium regulation.7

Treatment and Prevention

Treatment of Calcium Deficiency:

  • Calcium Supplements: If your calcium levels are significantly low, your doctor may prescribe calcium supplements. Always take supplements as prescribed by your healthcare provider.
  • Vitamin D Supplements: If you have a vitamin D deficiency, your doctor may recommend vitamin D supplements to improve calcium absorption.
  • Intravenous Calcium: In severe cases of hypocalcemia or when oral supplements are not suitable, calcium may be administered intravenously (directly into the bloodstream) under medical supervision.
  • Treating Underlying Conditions: If calcium deficiency is caused by an underlying medical condition, such as kidney disorders or certain medications, treating or managing that condition may help restore calcium levels. 6, 7
  • Adjusting Medications: If certain medications are contributing to calcium deficiency, your doctor may adjust the dosage or switch to alternative medications.

Prevention of Calcium Deficiency:

  • Balanced Diet: Consume a diet rich in calcium-containing foods, including dairy products (milk, yoghurt, cheese), leafy greens (kale, broccoli), nuts, and seeds. Fortified foods, such as fortified plant-based milk and orange juice, can also be good sources of calcium.
  • Vitamin D: Ensure you get enough vitamin D, either through sunlight exposure (limited time outdoors, especially in sunny weather) or through supplements if needed.
  • Regular Exercise: Weight-bearing exercises, such as walking, jogging, and resistance training, can help maintain bone health and prevent bone loss.
  • Moderate Caffeine and Alcohol Intake: Consuming excessive amounts of caffeine and alcohol can disrupt calcium absorption, so it's advisable to consume them in moderation.
  • Avoid Smoking: Smoking can contribute to bone loss, so quitting smoking is beneficial for overall bone health.
  • Routine Health Checkups: Regular visits to your healthcare provider can help identify any underlying medical conditions or risk factors for calcium deficiency.6, 7
  • Monitor Medications: If you are taking medications that may affect calcium levels, discuss potential side effects and management strategies with your doctor.5

When to seek medical advice?

You should seek medical advice if you suspect you have calcium deficiency or experience any symptoms that could indicate hypocalcemia. Some specific situations when you should reach out to a healthcare professional include:

  • Unexplained Symptoms: If you have symptoms such as muscle cramps, tingling or numbness in the fingers or toes, fatigue, mood changes, or any other unexplained symptoms that might be related to calcium deficiency, it's important to get them evaluated.
  • Known Risk Factors: If you have known risk factors for calcium deficiency, such as a diet low in calcium-rich foods, vitamin D deficiency, kidney problems, or conditions affecting the parathyroid glands, consider discussing your concerns with a doctor.
  • Recent Surgeries: If you have undergone any surgeries involving the parathyroid glands or intestines, it's essential to be aware of potential calcium imbalances and report any symptoms.
  • Medication Usage: If you are taking medications that may affect calcium levels, such as diuretics, anticonvulsants, or steroids, consult your healthcare provider about monitoring and managing calcium levels.
  • Existing Health Conditions: If you have medical conditions that could impact calcium absorption or metabolism, such as celiac disease, inflammatory bowel disease, or chronic kidney disease.
  • Long-Term Use of Acid-Suppressing Medications: If you are on long-term acid-suppressing medications like proton pump inhibitors (PPIs), they may reduce calcium absorption, and you should seek medical advice to monitor calcium levels and address any potential deficiencies.
  • Pregnancy and Breastfeeding: Pregnant and breastfeeding women should ensure they are getting enough calcium, as their bodies have higher calcium requirements during these periods.


Calcium deficiency, also known as hypocalcemia, is a condition characterized  by an insufficient level of calcium in the bloodstream. Calcium is crucial for muscle, nerve, and bone health. Symptoms include cramps, tingling, weakness, and mood changes. Causes include diet, vitamin D deficiency, kidney issues, medications, and hormones. 

Diagnosis is through blood tests, and treatment may involve supplements and addressing underlying conditions. Preventive measures include a balanced diet, enough vitamin D, exercise, and limiting alcohol and caffeine. Seek medical advice if you suspect calcium deficiency for proper evaluation and management.


  1. Cormick G, Belizán JM. Calcium intake and health. Nutrients [Internet]. 2019 Jul 15 [cited 2023 Aug 4];11(7):1606. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6683260/ 
  2. Shlisky J, Mandlik R, Askari S, Abrams S, Belizan JM, Bourassa MW, et al. Calcium deficiency worldwide: prevalence of inadequate intakes and associated health outcomes. Ann N Y Acad Sci [Internet]. 2022 Jun [cited 2023 Aug 4];1512(1):10–28. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9311836/ 
  3. Fong J, Khan A. Hypocalcemia. Can Fam Physician [Internet]. 2012 Feb [cited 2023 Aug 4];58(2):158–62. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3279267/ 
  4. Mn A, J V. The western-style diet, calcium deficiency and chronic disease. J Nutr Food Sci [Internet]. 2016 [cited 2023 Aug 4];06(03). Available from: https://www.omicsonline.org/open-access/the-westernstyle-diet-calcium-deficiency-and-chronic-disease-2155-9600-1000496.php?aid=72703 
  5. NHS; Calcium: Vitamins and minerals [internet]. [updated 2020 August 03]. Available from: https://www.nhs.uk/conditions/vitamins-and-minerals/calcium/
  6. Lanham-New SA. Importance of calcium, vitamin D and vitamin K for osteoporosis prevention and treatment: Symposium on ‘Diet and bone health.’ Proceedings of the Nutrition Society [Internet]. 2008 May [cited 2023 Aug 4];67(2):163–76. Available from: https://www.cambridge.org/core/product/identifier/S0029665108007003/type/journal_article 
  7. Pepe J, Colangelo L, Biamonte F, Sonato C, Danese VC, Cecchetti V, et al. Diagnosis and management of hypocalcemia. Endocrine [Internet]. 2020 Sep 1 [cited 2023 Aug 4];69(3):485–95. Available from: https://doi.org/10.1007/s12020-020-02324-2
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Leona Issac

Bachelor of Dental Surgery, Rajiv Gandhi University of Health Sciences

Master of Public Health, University of Wolverhampton

Dr Leona Issac is a dynamic professional with a diverse background in dentistry and public health. With extensive experience as a dentist, she offers valuable insights into oral health, complemented by her Master’s degree in Public Health, which provides her with a comprehensive understanding of healthcare systems and their integration with dentistry. Her dedication to public health has led her to actively engage in health promotion, disease prevention and healthcare policy advocacy. Dr Leona continues to make a significant impact on the health and wellbeing of communities through her exceptional work and dedication to her field.

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