Why does our body need calcium?
Needless to say, calcium is one of the most abundant minerals in the body. It does a whole lot more than just strengthening our bones and teeth. Hence the deficiency of calcium can affect many of our body functions.
Calcium is necessary for many important processes like:
- Formation and strengthening of bones and teeth
- Muscle contractions
- Clotting of blood
- Maintaining a normal heart rhythm
- Normal enzyme functioning
Though 99% of the calcium in our body is stored in the bones, other tissues like muscles and blood also contain calcium.
The body continuously regulates the calcium present in the blood as well as the cells by moving it in and out of the bones as and when there is calcium deficiency.
When the intake of calcium is less or when there is a calcium deficiency, the body maintains its levels in the blood and cells by mobilizing them from the bones, thereby weakening them.
How much calcium do you need?
Calcium is obtained from the foods we eat.
Many foods are naturally rich in calcium, and it is important to include such foods during each meal.
Some of the good sources of calcium are:
- Soya beans
- Dairy products like milk, yogurt, cheese
The amount of calcium required by an individual depends upon their age, gender, and other factors like underlying health conditions and overall health.
The normally followed dietary recommendations for calcium are:
- Women (50+): 1200 mg per day
- Women (<50 years): 1000 mg per day
- Men (71+): 1200 mg per day
- Men (<71 years): 1000 mg per day
How do your genes influence your calcium requirements?
CASR or Calcium-Sensing Receptor is an extracellular G-protein that plays a vital role in calcium homeostasis. The gene that encodes this protein, located on chromosome 3, is usually expressed at very high levels in the parathyroid glands, thyroid, intestine, and kidneys.
The CASR protein forms a stable homodimeric receptor. The receptors signal into the cells when calcium ions bind to them. This causes a downregulation of gene expression that influences calcium homeostasis in the parathyroid areas. Simultaneously, there's a rise in the levels of calcium in the kidney, and the excretion of sodium chloride (salt) is lessened.
Also, the binding of calcium to the CASR gene occurs within the normal physiological limits of the calcium ions. This leads to a steep dose-response curve and results in tight control of calcium levels in the blood.
Variations in this gene have been extensively studied. One variation, a G to T transition, alters the receptor efficacy. This can influence parathyroid hormone secretion, increase calcium clearance, and finally affect calcium homeostasis.
The CYP24A1 gene is located on chromosome 20 and belongs to the cytochrome P450 superfamily of enzymes. Particularly, the gene provides the instructions required for making the 24-hydroxylase enzyme.
This enzyme is responsible for controlling the amount of active vitamin D available in the body. Vitamin D is absolutely essential for the proper absorption of calcium from the intestines and is also necessary for various processes required for bone and tooth formation. Variations in this gene that affect vitamin D consequently causes inefficient calcium absorption.
Several other mutations are also found associated with this gene. One of which is known to cause idiopathic infantile hypercalcemia.
GATA3 or GATA binding protein 3 is a gene that is located on chromosome 10 and belongs to the GATA family of transcription factors.
Any defects in this gene result in hypoparathyroidism along with sensorineural deafness and renal dysplasia.
Hypothyroidism causes a reduction in the calcium levels in the blood, i.e., hypocalcemia.
Calcium deficiency - Hypocalcemia
The condition when the calcium levels in the blood are low is called hypocalcemia. It is more common in women, and also more so as people age.
Calcium deficiency - Causes
- Hormonal changes in women
- Poor intake of calcium
- Dietary intolerance to foods containing calcium
- Medications that affect calcium absorption
- Genetic factors
Other causes that can lead to hypocalcemia include:
- Low levels of vitamin D (therefore, reduced calcium absorption)
- Chemotherapy drugs
- Hypophosphatemia (decreased phosphate levels) and hypomagnesemia (decreased magnesium levels)
- Removal of the parathyroid gland as a part of thyroid gland tissue during surgery
You might also be interested in: Are You Meeting Your Vitamin D Needs? Let Us Ask Your VDR Gene!
Calcium deficiency - Symptoms
Early-stage hypocalcemia does not show any symptoms, which only appear when the disease progresses.
Some symptoms of hypocalcemia include:
- Muscle problems such as aches, spasms, cramps
- Increased numbness and tingling in the arms, legs, hands, and feet
- Severe fatigue, lack of energy
- Dry skin
- Weak and brittle nails
- Osteoporosis that increases the chances of breaking or brittle bones
- Dental problems like poor oral health, week roots of teeth, brittle teeth, gum irritation, increased cavities
Treatment for calcium deficiency
It is advisable not to self-treat calcium deficiency by taking OTC calcium supplements as it can negatively impact one's health by interacting with any other medications one may be taking.
Based on the calcium levels, your physician will provide you with the right calcium supplement and ask you to increase your dietary intake.
Commonly advised calcium supplements are:
Including calcium-rich foods in each of the meals also tremendously helps to treat the deficiency.
More about calcium supplements
Who should consider calcium supplements?
The following groups of people may be at a risk for calcium deficiency and can consider taking prescribed supplements:
- Individuals with lactose intolerance
- People with osteoporosis
- Individuals who consume excess proteins or sodium (as these minerals cause increased excretion of calcium)
- People undergoing long-term corticosteroid treatment
- Individuals who are unable to absorb enough calcium due to digestive issues like celiac disease, IBD, etc.
- People with health conditions like Crohn's that limit the body's ability to absorb calcium
Types of calcium supplements
Calcium supplements are primarily of two types: Calcium carbonate-based and calcium citrate-based. Each type of calcium supplement, contains a different calcium salt and different amounts of elemental calcium.
The supplements that are calcium carbonate-based are cheaper and therefore, more popular. They contain 40% elemental calcium. The citrate-based supplements contain about 21% of elemental calcium. Other calcium supplements contain salts like calcium lactate (containing 13% elemental calcium) and calcium gluconate (9% elemental calcium).
Combining calcium supplements with vitamin D intake can help increase the absorption of calcium. Magnesium is also a good substitute for vitamin D.
Side effects of calcium supplements
Calcium can cause calcification of blood vessels and thus, the usage of calcium supplements raise some serious cardiac concerns. However, no study has shown a solid proof of calcium supplements posing a threat to the heart health.
On the other hand, there has also been no conclusive proof to show that calcium supplements indeed help in preventing diseases like osteoporosis.
According to a 2015 study, calcium supplements increase the risk of kidney stone recurrence, especially in people who are prone to it.
Calcium supplements and heart disease
There is a split in the medical world over whether calcium supplements cause heart disease or not.
While some say these calcium supplements do not precipitate heart disease, others say that the calcium from the supplements can harden or calcify the existing plaque in the blood vessels.
However, research suggests the following about the relationship between calcium supplements and heart disease:
- The supplements that concern most doctors are those with pure calcium
- There is no conclusive proof that calcium supplements with vitamin D can cause heart disease
- Calcium that we get from dietary sources such as leafy greens and dairy products is not a cause of worry
What is hypercalcemia?
When the calcium level in the blood is over 10.3 mg/L, the condition is called hypercalcemia. Excessive calcium in your blood can be harmful to your bones, kidneys, and also affect the way the other organs in your bodywork.
Hypercalcemia is usually the effect of overactive parathyroid glands that result in an increase in the blood calcium levels. Other causes of hypercalcemia include:
- Cancers, especially lung and breast cancer
- Certain medications
- Taking excess calcium or vitamin D supplements
- Renal disorders
Symptoms of hypercalcemia
The symptoms of hypercalcemia differ with each organ.
- Kidneys: Excessive calcium in your means that your kidneys need to work harder to filter it. This causes increased thirst and frequent urination.
- Digestive system: Excessive calcium can cause nausea, vomiting, stomach upset, and in some cases, constipation
- Bones: In cases where hyperparathyroidism results in hypercalcemia, the calcium from the bones is leached out into the blood due to parathormone. This causes bone pain and weakens them.
- Muscles: Hypercalcaemia can cause muscle weakness and spasms.
- Heart: Though it has not been proven yet, severe hypocalcemia might interfere with the proper functioning of the heart. It can cause palpitations, arrhythmias and other cardiac problems.
- Brain: Hypercalcaemia can cause lethargy, confusion, fatigue and even depression.
Treatment and prevention of hypercalcemia
In individuals with mild hypercalcemia, the calcium levels usually return to normal over time and do not need any treatment.
The physician may continue to monitor the calcium levels and the health of the kidneys while the calcium levels return to normal. However, when calcium levels do not return to normalcy on their own, the doctor will recommend further testing to determine the underlying cause of high calcium levels.
Possible treatments to reduce calcium levels include IV fluids and medications like calcitonin and bisphosphonates. If hypercalcemia is due to excessive vitamin D, hyperactive parathyroid glands or any other underlying condition, the doctor will focus on removing or treating this cause.
One of the basic things to do to keep your calcium levels in check is maintaining a healthy and balanced lifestyle.
- Drink lots of water: Helps you stay hydrates, reduces calcium levels, and also prevents the formation of kidney stones
- Quit smoking: Having an imbalance in calcium levels can negatively impact one’s bone health. Smoking accentuates bone loss, and thus, it is best to quit smoking in order to keep calcium levels in check.
- Exercise routine: This helps keeps your bones and muscles healthy and strong
- Follow prescriptions: Always stick to prescriptions when taking calcium or vitamin D supplements. Excessive consumptions of these supplements can have negative health effects.
One of the best ways to ensure healthy and optimum calcium levels is by sufficient dietary intake of the mineral. Some foods that are exceptionally high in calcium are:
- Seeds: Many seeds such as sesame seeds, poppy seeds, and chia seeds are rich in calcium
- Dairy products: Milk and other dairy products such as yogurt and cheese are storehouses of calcium and are, therefore, important for young kids and older adults.
- Greens: Vegetables including the leafy greens such as broccoli, spinach, kale, Brussel sprouts, etc., are particularly rich in calcium and magnesium.
- Beans and Lentils
- Fortified foods: A large number of foods are fortified to make them healthier. They are fortified to improve their nutritional value.
- Soya and Soya products like tofu, tempeh, and edamame are also rich in calcium.
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Updated 08 May 2020