Salt tablets are available over the counter in health stores and online. But are they effective in combating low levels of sodium in the body?
And should people use them to offset the effects of intensive exercise?
This article looks at when people use salt tablets, their benefits and side effects, and whether they can help prevent dehydration.
Salt tablets, or salt pills, may help replace low levels of sodium in the body. Sodium is both a mineral and an electrolyte. The body needs electrolytes to regulate fluids in the body, ensuring hydration and helping the body function well.
A doctor may prescribe or recommend salt tablets when a person has symptoms of hyponatremia, meaning they have low levels of sodium in the blood. A normal blood sodium level is around 135–145 milliequivalents/liter (mEq/L).
- kidney failure, when the kidneys are unable to rid the body of extra fluid
- congestive heart failure, when excess fluid builds up in the body
- diuretics (water pills), which increases sodium in urine
- more sweating than usual
- severe vomiting or diarrhea, which depletes the body of fluids and salt
- excessive thirst, causing too much fluid intake
Exercise can also cause exercise-associated hyponatremia. This happens when athletes, often long-distance runners, consume too much water during physical activity, depleting natural levels of sodium.
As a result, many marathon and long-distance runners take salt tablets before or during long runs to avoid cramps associated with low levels of electrolytes.
An underlying medical condition, such as cystic fibrosis, can cause the body to lose more salt in sweat, especially in children and young adults with the condition. A doctor may prescribe salt tablets to prevent hyponatremia from developing.
People take salt tablets for many reasons, such as to:
- improve hydration during exercise, particularly during endurance activities
- keep a good balance of electrolytes in the body after illness or exercise
- manage symptoms and side effects of underlying conditions
There is some evidence to suggest that salt tablets are an effective treatment for hyponatremia.
However, there is less evidence to suggest that they are effective in preventing illness caused by long-distance running.
A 2021 study into the effect of sodium supplements and climate during ultramarathons, found that salt tablets did not appear to protect athletes from symptoms of low electrolytes, such as cramps. Instead, they found that factors such as body mass, longer training distances, and avoiding excessive fluid intake were more important in preventing these issues.
Salt tablets should not cause any specific side effects at their recommended dosage. However, if a person takes far more than the recommended dosage, they may experience hypernatremia, which is when a person has too much salt in their body.
Symptoms of hypernatremia include:
- swelling of the tongue
- flushed skin
- a fast heart rate
- high blood pressure
A person taking salt tablets who notices any of the above symptoms should stop taking them straight away and call a doctor.
Before taking salt tablets, a person should inform their doctor of anything that may be relevant, such as allergies, underlying health conditions such as high blood pressure or kidney disease, or whether they are pregnant or breastfeeding.
People can purchase salt tablets over the counter, but if a person takes an excessive amount of salt tablets, they may experience potentially serious symptoms.
People taking salt tablets should follow the guidance of their doctor or follow the dosage instructions on the packaging. Taking tablets with food may reduce the likelihood of an upset stomach.
Salt tablets usually contain around 400 milligrams of sodium. They should be safely stored at room temperature, around 59–86°F (15–30°C).
People can dissolve salt tablets in water to make an isotonic solution. Dissolve one tablet in 4 ounces of water and take as directed by a doctor or healthcare professional.
People who are taking salt tablets to prevent heat cramps should take one tablet orally as directed by a doctor.
There is evidence to suggest that salt tablets can help prevent dehydration in certain situations.
It is important to note that this study showed the sodium solution outperformed salt tablets when people took them on their own. People should drink plenty of water with the tablets.
People who wish to take salt tablets to help with dehydration during exercise should talk with a doctor before taking them. They may consider choosing salt solutions and electrolyte or sports drinks instead of salt tablets alone.
Salt tablets may help increase low levels of sodium in the blood and balance electrolytes in the body. They may be suitable for use by people with underlying health conditions and athletes.
A person who takes more salt tablets than the recommended dose may notice irritability, a high heart rate, and dizziness, among other symptoms. People wishing to take salt tablets for exercise should talk with a doctor first.