Iodized Salt: Benefits, Side Effects, Best Time to Take It & More

Iodized Salt

(Salt with iodine)

What is iodized salt?

Iodized salt was introduced in 1924 as a means to correct iodine deficiency. Added iodine is a benefit to those at risk of not getting enough. Most brands selling iodized salt sell refined table salt with added iodine. However, you may come across sea salt with added iodine as well, which is a better choice. Besides iodine, iodized salt is mostly a mixture of sodium and chloride, two minerals necessary for proper hydration, digestion, absorption of nutrients, and more. Salt intake needs to be kept in balance with water and other electrolytes, such as potassium and magnesium, as too much salt without adequate intakes of these can lead to high blood pressure and other health problems. This article is about the main benefits of iodized salt, its potential side effects, how much you need, and more.

What does iodized salt do to the body?

Iodized salt is mostly a mixture of iodine, sodium, and chloride.

Sodium and chloride are both electrolytes, which means they can fully dissolve in water.

With a help of chloride, sodium attracts water molecules and transports them through the body.

Salt spends most of its time outside of human cells, hydrating the blood and other parts of extracellular fluid (fluids outside the cells).

While sodium itself cannot hydrate the cells in your body, it does so with a help of potassium. This process is called the sodium-potassium pump and consumes 20-40% of all body’s energy at rest.

In simplified terms, potassium hydrates all cells in the body, and sodium is needed to hydrate everything outside the cells.

Too much sodium from iodized salt increases the water content in the blood, which exerts more pressure on the walls of your blood vessels, causing high blood pressure. This increase in extracellular fluid can also lead to swelling.

Potassium can mitigate these risks to a great extent by moving excess sodium from the blood into the urine. This is why these electrolytes have to be kept in balance.

Besides hydrating the body, salt is also necessary for transporting food, digesting it, and absorbing glucose, amino acids, and some vitamins and minerals.

Sodium also helps transport most nutrients, hormones, toxins, and more.

This mineral is important for controlling the proper level of acidity in the body as a whole and individual tissues and compartments within cells.

Salt and potassium allow neurons to respond to neurotransmitters or other signals, and to transmit signals to other neurons or muscle cells.

Iodine is extremely important for proper thyroid function and a healthy immune system.

How much iodized salt should you consume?

Iodized salt typically contains about 45 mcg of iodine. Since the optimal iodine intake is about 150-300 mcg, as little as 3 grams of iodized salt should be enough to provide enough iodine for the day.

In general, all-caused mortality is at its lowest in people who consume 2000-3000 mg of sodium per day, which equals about 5-8 grams of iodized salt.

To prevent sodium deficiency, you want to shoot for at least 2000 mg of sodium. Any less seems insufficient for anyone who is at least moderately active.

All-caused mortality starts increasing exponentially when people consume over 3500 mg of sodium, or about 9 grams of salt.

This doesn’t take into account that some people are more active than others and thus need more sodium. If you sweat a lot, you should get away with higher amounts of sodium, assuming you also drink enough water and consume enough potassium. Heavy sweating increases your need for sodium by 1000-3000 mg/d.

Potassium is needed to get rid of excess sodium and vice versa. Therefore, these two minerals should be kept in balance.

To prevent high blood pressure, you should consume at least 1 mg of potassium for every 1 mg of sodium.

The easiest way to find out whether or not you are consuming enough salt is by listening to your body. If you crave salt, you likely need more of it. If you are appalled by it and instead crave water, you should cut back on salt.

Possible side effects of too much iodized salt

These side effects are dose-dependent. The risk for them increases (often linearly but sometimes exponentially) as you increase the dose. Some of the side effects only apply to very high doses.

Dehydration – Sodium is needed to transport water and hydrate the body. However, if you consume too much salt, your body has to get rid of it through sweat or urine. Both of these require lots of water which can lead to dehydration. Keep in mind that too little sodium can lead to dehydration as well by not absorbing water properly.
High blood pressure – Too much sodium from iodized salt increases the water content in the blood, which exerts more pressure on the walls of your blood vessels, causing high blood pressure. High potassium intake can reduce the increase in blood pressure to a great extent.
Swelling – Extracellular fluid in your face, hands, legs, or virtually any part of your body could accumulate and lead to swelling if you consume too much iodized salt.
Cardiovascular diseases – High blood pressure can directly increase the risk of cardiovascular diseases, such as heart attacks and stroke.
Potassium deficiency – When you consume too much salt, potassium helps flush out excess sodium by driving it into the urine. This increases the need for potassium.
Iodine toxicity – While toxicity is rare, taking high amounts of the mineral could lead to some health problems over time. For example, over 18,000 mcg/d can cause goiter. Extremely high doses (in grams) could also lead to abdominal pain, fever, nausea, vomiting, and coma. It’s best to avoid very high doses since they do not appear to be safe to take over a long period. Specifically, you want to stay below 1000 mcg a day.
Worsened Hashimoto’s disease – Iodine in doses as low as 200 mcg daily has been shown to worsen symptoms of Hashimoto’s thyroiditis and Grave’s disease, autoimmune conditions that involve the body attacking its thyroid gland. The supplement may not be safe if you have one of these conditions.
Worsened thyroid health – Doses of iodine higher than 1000 mcg taken daily over a long period can negatively change blood markers of thyroid health. However, this may not be a concern since some cultures eat as much as 15000 mcg daily without any apparent side effects.

Who should lower their sodium intake?

You should probably lower your sodium intake if you:

drink too little water (while sodium is needed to absorb water and hydrate properly, consuming too much salt without enough water makes it hard to flush excess sodium out of the body, which can lead to serious problems)
are deficient in potassium (these two minerals have to be kept in balance as they are both necessary in the sodium-potassium pump and each of them is necessary to get rid of the excess of the other)
are deficient in magnesium (too much sodium with too little magnesium significantly increases the risk for high blood pressure)
eat lots of foods with added salt (such as cheese, deli meat, salted nuts, etc.)
experience muscle cramps and they are more intense on days you eat more salt
suffer from high blood pressure
often get dehydrated
experience pain in the eyes when your sweat drops in them

Who needs more sodium?

You should probably increase your sodium intake if you:

sweat a lot (heavy sweating increases your need by 1000-3000 mg/d)
drink lots of water
filter your water (it is best to add salt and preferably other minerals into filtered water to make it easier to absorb)
suffer from low blood pressure
experience symptoms of deficiency

Symptoms of sodium deficiency

Sodium deficiency is called hyponatremia. The most common signs of hyponatremia include:

headaches
urinating too much at night
muscle cramps that get solved when you eat salt
muscle weakness
dehydration despite drinking too much water
nausea
vomiting
low blood pressure
fainting

Keep in mind that these signs are just indications of a deficiency. If you experience some or even most of them, it does not necessarily mean you need more sodium.

With that said, if you experience many or most of these symptoms, there is a high chance that you are not getting enough sodium. The more of these symptoms you have and the more severe they are, the more likely you are to have a deficiency.

All of these signs should disappear almost immediately after you consume sodium.

Other types of salt

The different types of salt include:

Table salt – This is the cheapest and most popular type of salt. Unfortunately, it is refined and doesn’t contain most trace minerals that unrefined salts contain.
Iodized salt – This salt was introduced in 1924 to correct iodine deficiency. Added iodine is a benefit to those at risk of not getting enough. Most brands selling iodized salt sell table salt with added iodine. However, you may come across sea salt with added iodine as well, which is a better choice.
Kosher salt – Kosher salt is mined from underground salt deposits.
Sea salt – Sea salt is made from drying salt water from the ocean or salty lakes. Besides taste, the main difference between sea salt and kosher salt is that sea salt contains small amounts of microplastics.
Himalayan salt – This type of salt further divides into white, pink, red, and black Hilamayan salts. The red color is mainly because of iron. The more red the salt, the more iron it contains. From a health perspective, this almost doesn’t matter since the amount of iron in an average Himalayan salt is only about 0.04 mg/g. Himalayan salt isn’t naturally black, it turns black during a heating process or manufacturers add activated charcoal to it.
Hawaiian salt – This is a type of sea salt with about as high iron content as Himalayan salt.
Celtic salt – Celtic salt tends to have a grey color. Health-wise, it is about the same as regular sea salt.
Fleur de Sel – This is an expensive type of salt with no extra health benefits.
Truffle salt – Truffle salt is even more expensive than Fleur de Sel and has an almost identical mineral composition to regular sea salt.
Sodium bicarbonate – While sodium bicarbonate (also called baking soda) isn’t a type of salt, it provides about 273 mg of sodium per gram. This form is effective for lowering acidity in the body and enhancing athletic performance.

Except for regular table salt, all other types of salt are great and worth consideration. Kosher salt and Himalayan salt may be slightly better than most types of sea salt since they do not contain nearly as many microplastics. However, the difference is tiny and sea salt is a great choice as well, especially if you are on a budget.

Food sources of sodium

Whole foods without added salt rarely contain considerable amounts of sodium. Most people get the majority of their salt intake from processed foods, such as deli meats, cheese, salted nuts, etc.

An average person in the developed world gets about 70-80% of salt from processed and prepared foods.

If you avoid processed food, you should get away with salting your food as much as you want and not overeat on salt, assuming you get a reasonable amount of potassium as well.

Best time to consume iodized salt

The best time to consume iodized salt is when you are drinking water. It makes the water more hydrating and decreases the risks related to too much sodium.

Just like you do with drinking water, split your sodium intake evenly throughout the day as opposed to consuming all of it at once.

Assuming it doesn’t lead to dehydration, iodized salt does not interrupt your sleep in any way. It may actually help you fall asleep and stay asleep if you wake up to pee at night.

If you are practicing OMAD or other forms of time-restricted eating, simply make the food less salty and add some salt to your drinking water outside the meals.

Interactions

Magnesium
Too much sodium with too little magnesium significantly increases the risk of high blood pressure. Magnesium can mitigate the risks associated with too much sodium to a great extent.
Potassium
Potassium is needed to get rid of excess sodium and vice versa. Therefore, these two minerals should be kept in balance. To prevent high blood pressure, you should consume at least 1 mg of potassium for every 1 mg of sodium (or 3 mg of iodized salt).
Water
Since the main function of sodium is transporting water inside the body, water and salt intake have to be kept in balance. Too much water can flush out sodium to the point of deficiency. Too little water and the body won’t be able to flush excess sodium without becoming dehydrated.

FAQ

Yes. Salt doesn’t negatively impact your sleep, assuming it doesn’t lead to dehydration. Salt might make it easier to fall asleep and stay asleep if you often wake up to pee at night.

Regular iodized salt doesn’t expire. Salts with added herbs, flavors, or iodine may deteriorate over time but that would typically take many years or decades.

Yes. Too much sodium in the system can lead to multiple health problems, such as high blood pressure, dehydration, and heart attack. This is especially the case if you don’t drink enough water or consume too little magnesium and potassium.

The most common reason people become deficient is that they actively avoid salt. However, many things can deplete your sodium levels and increase your need for this nutrient. These include sweating and drinking too much water.

Sodium typically stays in your body for 2-4 days after you consume it. However, this depends on many factors, such as how fast you lose sodium through sweat and urine.

Most sodium leaves the body through urine and sweat. Instead of thinking in terms of hours or days, consider how much sodium you flush out by sweating or peeing. People who have accumulated too much sodium in the body will excrete about 2000 mg per liter of sweat, which comes from about 6 grams of salt. The amount of salt in urine is about half.

Iodine, sodium, and chloride from iodized salt are all water-soluble.

No, it does not interfere with fasting in any significant way. Consuming at least some salt is very important during any water fast longer than a day. Avoiding salt during a fast can be dangerous.

References

Most of the information provided in this guide is supported by scientific research that can be found and verified in the PubMed medical library. We highly encourage you to use the library to verify anything said in this article. We excluded from consideration studies that are either confounded or have a high conflict of interest.

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