Thyroid and calcium relationship

The highly-organized relationship between the thyroid, the parathyroid and calcium is essential for normal functioning of the human body.

Both the thyroid glands and the parathyroid glands work alternatively, maintaining calcium levels within normal limits through the regulation of calcium levels in both the blood stream and bones. [[1], [2], [3]]

How can the thyroid gland affect calcium levels?

Talking about the thyroid gland is commonly associated with its ability and responsibility for secreting the hormones that regulate metabolism, which makes some think that that the thyroid gland has no more roles.

Importantly, the thyroid gland secretes another hormone named calcitonin, through which the thyroid significantly aids in calcium and phosphorus levels regulation.

When calcium level increases in the blood, the thyroid gland secrets more calcitonin, which in turn plays a dual role, as follows [[4]]:

  • Calcium absorption

Calcitonin improves the absorption rate of both calcium and phosphorus from the blood into bone cells.

  • Effect of osteoclasts

Calcitonin inhibits the effect of certain cells known as osteoclasts, decreasing calcium migration from the bones to the blood stream.

How can the parathyroid glands affect calcium levels?

The parathyroid glands are 4 glands directly located behind the thyroid gland. The main function of the parathyroid glands is to secrete parathyroid hormone, which in turn is responsible for regulating calcium levels in the body, along with calcitonin.

In case calcium decreases in blood stream, that stimulates the parathyroid glands to secrete parathyroid hormone, which increases calcium level in blood through 3 ways, as shown below [[5]]:

  • Calcium migration

Parathyroid hormone improves the activity of osteoclasts, increasing the rate of calcium migration from bones to blood.

  • Kidneys

Through kidneys, parathyroid hormone can controls calcium level, as it inhibits the rate of filtration of both calcium and magnesium, prolonging the time they stay in blood circulation. [[6]]

  • Human gut

Parathyroid hormone also improves the absorption rate of calcium, magnesium and phosphate from the gut, resulting in increasing calcium levels in blood. That occurs as a result of calcium’s stimulatory effects on the kidneys, causing them to synthesize more calcitriol.

That way the thyroid gland and parathyroid glands keep calcium levels within normal limits in both the blood stream and bones all the time.

What makes calcium levels very important?

Calcium is much more important than other elements.

While some are just aware of the role calcium plays in strengthening body bones [[7]]; actually, calcium has much more to do for the body, including:

  • Muscles contraction

Calcium is responsible for the contraction of all the body muscles, such as those of the legs, arms and the heart muscle. That’s why the parathyroid glands tend to increase the calcium level in blood, so as to ensure maintaining sufficient amounts of calcium for the muscles.

  • Nerve conduction

Along with muscles contraction, calcium is also responsible for efficiently conducting signals through nerves.

What if the relationship between calcium, the thyroid and parathyroid glands deteriorates?

In this case, calcium levels would abnormally increase or decrease, making the body much likely to many issues [1]. For example, abnormal calcium accumulation in the blood stream can cause osteoporosis, abnormal nerve conduction and over contraction of body muscles, and more importantly the heart muscle.

In contrast, low calcium level in the blood can result in calcification of bones, less efficient nerve conduction (numbness), and muscle contraction.

What can cause this relationship to deteriorate?

The issues listed below show certain disorders that sometimes occur with the thyroid gland or the parathyroid glands, deteriorating the relationship between calcium and these glands.

  • Hyperparathyroidism

The gland hyperactively works, mistakenly continuing to secrete parathyroid hormone, even when the blood level of calcium is normal or high. That can result in hypercalcemia and kidney stones [[8]].

  • Hyperthyroidism

Hyperthyroidism may result from many issues, such as Grave’s disease, causing the thyroid gland to overly secrete thyroid hormones.

  • Hypoparathyroidism

Hypoparathyroidism occurs when the parathyroid gland secrets less parathyroid hormone than normal, or when the secreted hormone doesn’t work efficiently.

  • Hypothyroidism

Hypothyroidism occurs when the thyroid gland fails to properly secrete enough amounts of thyroid hormones regularly. Its effects are detailed more specifically in the article here.

  • Goiter

Goiter is amongst the cases in which the relationship between calcium level and the parathyroid gland may deteriorate. Goiter refers to a swelling of the thyroid gland, which may affect the gland entirely or only a part.

  • Thyroid cancer

Although thyroid cancer seems to be kind of rare, it also can negatively affect thyroid hormones secretion.

  • Thyroid surgery

If thyroid surgery mistakenly leads to removing one or more of the parathyroid hormones, that is likely to cause the thyroid gland to lose its ability to regulate calcium levels.

How much calcium should people take?

Calcium should be taken daily and cautiously.

The Food and Nutrition Board established 2 types of values in order to help people avoid the harmful effects and disorders that are likely to occur in cases of both calcium deficiency and hypercalcemia [[9]].

Recommended Dietary Allowances of calcium

  • The infants aged 0-6 months are recommended to take 200mg/day; while those ranging from 7 to 12 months are recommended to take 250mg/day.
  • The Children ranging from 1 to 3 years are recommended to take 700mg calcium/day; while those aged 4 to 8 years should take 1000mg calcium daily.
  • The children aged 9-13 years should get 1300mg calcium daily, and so should those ranging from 14 to 18 years.
  • The adults ranging from 19 to 50 years should only get 1000mg calcium daily; while the calcium amount recommended for those ranging from 51 to 70 years differs, according to gender, as follows:
  • Males: 1000mg/day.
  • Females: 1200mg/day.
  • The adults aged 71 years or more are recommended to take 1200mg of calcium daily.
  • The pregnant and breast-feeding women aged 14-18 years should consume 1300mg of calcium daily; while those ranging from 19 to 50 years should only consume 1000mg of calcium daily.


Tolerable Upper Intake Levels of Calcium

The Tolerable Upper Intake Levels show the maximum amount of calcium that can be safely administered daily, as follows [9]:

  • The infants aged 0-6 months are allowed to take calcium up to 1000mg/day; while those ranging from 7 to 12 months are allowed to take up to 1500mg/day.
  • The Children ranging from 1 to 8 years are allowed to take up to 2500mg of calcium/day; while those aged 9 to 18 years are allowed to take up to 3000mg calcium daily.
  • The adults ranging from 19 to 50 years are allowed to administer up to 2500mg calcium daily; while those aged 51 years or older are allowed to only administer 2500mg of calcium/day.
  • The adults aged 71 years or more are recommended to take 1200mg of calcium daily.
  • The pregnant and breast-feeding women aged 14-18 years are allowed to consume up to 3000mg of calcium/day; while those ranging from 19 to 50 years are allowed to only consume 2500mg of calcium daily.

The best sources of calcium

According to the National Institute of Health, the foods listed below should be considered in order to get sufficient amounts of calcium [[10]].

  • Milk, yogurt, and cheese
  • Vegetables, such as Chinese cabbage, kale, and broccoli.
  • Grains fortified with calcium
  • Foods fortified with calcium, such as fruit juices and drinks, tofu, and cereals.

Along with foods, drinks, it’d be beneficial to consider dietary thyroid supplements so as ensure getting adequate amounts of calcium daily, especially for those not eating variant foods, the elderly and the busy people who are much likely to not pay attention to what they eat/or how much calcium they get from each meal, in addition to those struggling with issues that can negatively affect the absorption rate of calcium from the gut.

Many forms of calcium are available in the market, such as calcium gluconate, calcium phosphate and calcium lactate. But, the most common forms are only two, including calcium carbonate and calcium citrate.

  • Calcium carbonate

That is much more common and sheep than calcium citrate. The dietary supplements containing calcium carbonate can be taken either with or without food, as the gastric acids in the stomach can improve their absorption rate.

  • Calcium citrate

As the absorption of calcium citrate is not dependent on the gastric acid, the supplements containing calcium citrate are specifically beneficial to the people struggling with gastric issues, such as low-gastric-acid (achlorhydria ), irritable bowel syndrome and inflammatory bowel disease.


[1]  Begic-Karup S., et al. Serum calcium in thyroid disease. Wien Klin Wochenschr. 2001 Jan 15;113(1-2):65-8.


[2]  Dinesh Kumar Dhanwal. Thyroid disorders and bone mineral metabolism. Indian J Endocrinol Metab. 2011 Jul; 15(Suppl2): S107–S112. doi:  10.4103/2230-8210.83339.


[3] Mohan HK., et al. Thyroid hormone and parathyroid hormone competing to maintain calcium levels in the presence of vitamin D deficiency. Thyroid. 2004 Sep;14(9):789-91.


[4] Inzerillo AM., et al. Calcitonin: the other thyroid hormone. Thyroid. 2002 Sep;12(9):791-8.


[5]  Chen RA., et al. Role of the calcium-sensing receptor in parathyroid gland physiology. Am J Physiol Renal Physiol. 2004 Jun;286(6):F1005-11.


[6]  McCaffrey Ct.,  and Quamme G A., Effects of thyroid status on renal calcium and magnesium handling. Can J Comp Med. 1984 Jan; 48(1): 51–57.


[7] Elias E. Mazokopakis, et al. Interaction between levothyroxine and calcium carbonate. Can Fam Physician. 2008 Jan; 54(1): 39 .


[8]  PTH parathyroid hormone [ Homo sapiens (human) ]. Gene ID: 5741, updated on 8-Oct-2017.


[9] Food and Nutrition Board. DRI Tables and Application Reports. United States Department of Agriculture. National Agricultural Library


[10] Office of Dietary Supplements. Calcium. Fact Sheet for Health Professionals. National Institute of Health. Updated: November 17, 2016.

Iodine and Benefits for Thyroid Health

You’ve probably heard a lot of people talk about how Iodine is essential for thyroid health.

Something along the form of what’s below:

Without adequate levels of iodine, your body will not be able to produce the thyroid hormones that it needs. Without these thyroid hormones, you will be at risk of developing hypothyroidism and goiter, among many other maladies.

But have you’ve ever wondered what exactly Iodine is and how exactly it helps the thyroid?

This article gives a brief overview answering your questions regarding Iodine along with references to scientific studies.

What is Iodine, Anyway?

Naturally occurring in soil and seawater, iodine is an element that controls thyroid function.

It is vital to the production of the thyroid hormones T3 and T4, substances that enable the thyroid gland to perform its jobs of as tissue metabolism and central nervous system development in children (the numbers next to the thyroid hormones means how many Iodine molecules are bonded to it.)

According to a study of Chung in 2014, the body requires 150 to 200 mcg of iodine, with as much as 80% of these going to the thyroid.

Here are the recommended daily intakes for iodine, depending on age and condition, according to the National Institutes of Health:

Age Recommended Dietary Allowance
Newborn – 6 months 110 mcg
7 – 12 months 130 mcg
1 – 8 years 90 mcg
9 – 13 years 120 mcg
14 years and above 150 mcg
Pregnant women 220 mcg
Lactating women 290 mcg


Since the body cannot produce iodine, a diet rich in this element is recommended by experts because of its numerous benefits on the thyroid gland, among many other organs in the body.

Here are some good sources of iodine:

  • Dairy Products. Cow’s milk, cheese, yogurt, ice cream
  • Saltwater fish, shellfish, shrimp
  • Nori, Kelp, Dulse
  • Iodized products, Iodized salt, iodized multivitamins

Now, before we get into why Iodine deficiency is bad for you and the benefits of proper, sufficient intake of Iodine, I believe it is also worth mentioning that some patients with Hashimoto’s Disease feel worse when taking significant amounts of Iodine.

That is not to say to outright avoid it – some patients feel better taking Iodine – and as you will read on you’ll find out why it’s so important.

But, if you have Hashimoto’s Disease (see Thyroid Advisor’s article on Hashimoto’s Disease if you don’t know what that is) it might be helpful keep that in mind and see how Iodine supplementation affects you.

Consequences of Iodine Deficiency to Thyroid Health

Pregnant women, contraceptive users, alcohol drinkers, tobacco users, individuals exposed to radiation and those taking selenium are just some of the many people at risk of developing Iodine deficiency.

If you belong to any of these groups – or if you are regularly unable to consume a diet rich in iodine – you may develop the following thyroid problems:

  • Also known as enlargement of the thyroid, this occurs because of the body’s attempt to meet the demand for thyroid hormone production. People who suffer from this ailment can experience breathing and swallowing problems, as well as breathing difficulties when lying down, and perhaps a noticeable lump on the neck.
  • A diet lacking iodine can lead to hypothyroidism because this element is needed to make thyroid hormones. Iodine deficiency is the leading cause of hypothyroidism worldwide.

In addition to the aforementioned conditions, iodine deficiency can have dire effects on pregnant or breastfeeding mothers potentially leading to developmental issues.

Fortunately, doctors test Iodine levels in the blood during pregnancy checkups and afterwards to make sure it gets accounted for.

Benefits of Iodine on Thyroid Health

With iodine vital to thyroid health, it comes as no surprise that it yields the following benefits:

  • Better brain function

Hypothyroidism due to iodine deficiency can manifest in the forms of memory gaps, cognitive problems, and diminished alertness.

That’s because thyroid hormones, which are synthesized with the help of iodine, play a major role in cognition and brain development.

In a study by Zimmerman et al, results showed that iodine provision in deficient children resulted to improved visual problem-solving skills and information processing in the participants.

  • Improves metabolism

As it has been mentioned, iodine is important for the production of thyroid hormones, which in turn play a big role in metabolism.

It follows that if you have a low-iodine diet, thyroid hormone synthesis will be decreased, and hypothyroidism might develop. This condition, according to a study of Mullur et al, is hallmarked by the signs of hypometabolism.

Symptoms include weight gain, high cholesterol levels, slower fat breakdown, and slower glucose generation in the body.

Additionally, Thyroid hormones stimulate one’s basal metabolic rate (BMR). In essence, the lower the BMR, the higher incidence of weight gain and obesity. Weight gain is also caused by the imbalance of the hormones estradiol, estrone, and estriol in the woman’s body.

However, iodine can bring back the balance of these hormones and inhibit the weight gain that occurs when these elements are out of sync.

Not only will iodine help normalize your thyroid function, it can help you enhance metabolism so you can achieve a healthier, fitter body.

Now wouldn’t you like to be healthy on the outside, as well as the inside?

  • Balances hormones

If your diet is devoid of iodine sources, you can expect to suffer from low thyroid hormone levels in the body, otherwise known as hypothyroidism.

Unfortunately, this can lead to a low metabolic rate, and you can develop symptoms such as a reduced appetite, low heart rate, and muscle stiffness, to name a few.

With recommended amounts of iodine in the body, you can achieve a euthyroid state wherein your thyroid gland is properly functioning.

  • Protects thyroid gland

Iodine is not only useful for hormone production; it paves the way for thyroid protection as well.

Central to this role is potassium iodide, a compound that protects the thyroid gland by blocking the absorption of radioactive iodine for as much as 24 hours.

The latter, which can be released in the event of a nuclear emergency, is easily absorbed by the thyroid gland. Think of the Fukushima event that happened in Japan in 2012. Such can result to tissue damage and other complications.

By taking potassium iodide, you can save your thyroid gland in the event that you were able to breathe, eat, or drink contaminated agents. But hopefully this is not something you have to worry about!

  • Enhances energy levels

Iodine can help boost your energy levels. This is because it is an essential factor in the creation of thyroid hormones, which in turn control metabolic pathways that establish energy storage and balance.

Lack of iodine leads to the development of hypothyroidism, one of the symptoms of which is a low energy level.

With proper iodine supplementation in the diet, you can achieve normal thyroid function and increased energy levels.

  • Lower cancer risk

Cancer cells grow at an exponential rate. However, iodine can stop it on its tracks by the virtue of apoptosis, or programmed cell death, according to Smyth’s research study titled ‘The thyroid, iodine and breast cancer.

As mentioned in the title and the text of the study itself, the element is specifically helpful for lowering the cancers of the thyroid and the breast.

It should be remembered though, that goitrogens or products that inhibit thyroid hormone production such as soy and cruciferous vegetables should be avoided throughout the course of supplementation.

If not, iodine’s apoptosis activities will not be able to take place – and cancer cells might then spread throughout the different parts of the body.

Other Benefits of Iodine

Apart from the thyroid gland, Iodine offers the following bodily benefits as well:

  • Improved Cardiovascular Health

Iodine found in desiccated thyroid has been shown to improve the heart health of many individuals.

A review of Hoption Cann in 2005 chronicled the many studies featuring Iodine’s role in improving the cardiovascular status of different patient populations.

Literature review showed that desiccated thyroid, which is rich in iodine, has been proven effective in lowering blood pressure and cholesterol levels in participants.

  • Better Immunity

Do you get the sniffles regularly?

Then it means that your immune system might be compromised because of stress, lack of sleep, among many other factors. You need not worry though as iodine can help enhance your immunity.

Like Vitamin C, which is another one of the great vitamins for thyroid health, Iodine boosts antioxidant activity, so your body can defend itself from free radicals.

  • Reversal of Fibrocystic Breast Changes

With symptoms such as lumpiness and breast discomfort, fibrocystic breast changes encompass non-cancerous changes in the mammary gland.

Although this is the case, it increases one’s risk of developing breast cancer.

Fortunately, iodine can reverse this change, as seen in many studies.

Results from a study by Eskin et al show that iodine deficiency in rats leads to fibrocystic breast changes, while iodine replacement reverses these changes.

Similar results were seen in Ghent et al’s study, wherein iodine treatment, specifically molecular iodine, yielded clinical improvements in the symptoms of fibrocystic breast disease.

  • Wound Treatment

Leg and foot ulcers and gum infections, are painful and bothersome. If left untreated, any of these can lead to a systemic bacterial infection. Iodine can prevent such, when applied topically at the affected areas.

Apart from healing said wounds, iodine is known to reduce the chances of re-infection as well.

Iodine Precautions

While iodine is beneficial for thyroid health, keep the following precautions in mind should you decide to take iodine supplementation:

  • Drink Moderately… Iodine Supplements, that is!
  • Make sure to follow the recommended daily intake specified above. Avoid going above 1000 mcg per day as this can interfere with the normal functioning of your thyroid gland. Symptoms of iodine overdose include fever, vomiting, diarrhea, nausea, cyanosis, and a burning sensation in the mouth and throat.
  • Consult with your Physician. This is especially the case for pregnant or nursing mothers. Going beyond the recommended daily allowance can have deleterious effects on the baby, such as hypothyroidism and goiter.
  • Avoid “Tincture of Iodine.” Used to disinfect wounds, this is not intended to be ingested, at any cost! They should be used topically only, to treat the infections stated above. Orally taking in even a small amount can bring unwanted changes to your body, even death.

Iodine Interactions

If you are or if you plan on taking iodine supplements for your thyroid health, be wary of taking them with the following medications as it can cause untoward reactions.

  • Anti-Thyroid Medications. If you have hyperthyroidism and currently taking drugs such as Methimazole, iodine supplements can have an additive effect and could lead to the development of hypothyroidism.
  • Angiotensin-Converting (ACE) Inhibitors. Blood pressure drugs such as Fosinopril, Lisinopril, and Benazepril, when taken with iodine supplements, can lead to increased potassium levels in the body or hyperkalemia.
  • This blood pressure medication contains high levels of iodine, and can lead to hyperthyroidism when taken with iodine supplementation.
  • Used in treating mood disorders, this drug, when taken with iodine supplements, can lead to the further development of hypothyroidism.
  • Potassium-Sparing Diuretics. Similar to the effect of ACE Inhibitors, Amiloride or Spironolactone intake with iodine supplements can lead to the development of hyperkalemia.

Similarly, if you are taking potassium iodide supplements alongside blood thinners such as Coumadin, the latter’s effect on the body is decreased.

This can lead to the development of blood clots which can get lodged in the small vessels of the lungs or the brain.

Iodine deficiency is a common problem in the world, and this often leads to poor thyroid health. For most patients, adding Iodine supplementation can help their hypothyroidism.

With the element’s numerous benefits on the thyroid gland – and other organs in the body – it is but recommended that you take iodine supplementation at doses prescribed by your physician.


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