Sodium Explained

A spilled salt shaker on a black background.

WHAT IS SODIUM?

Sodium is a macromineral that helps the muscles and nerves function properly. Whilst it often receives bad publicity (due to its close links with salt), sodium is actually essential for good health. In this article I will be discussing sodium and its functions in greater detail.

WHEN WAS SODIUM DISCOVERED?

Humans have been aware of sodium compounds throughout history. Glass (which is made using sodium carbonate) was being manufactured on a large scale in Egypt as early as 1370 B.C. However, although there was an awareness of sodium from an early date, people struggled to distinguish it from potassium until the eighteenth century. Once chemists realised the two elements were distinct they then started working towards isolating them.

Sir Humphry Davy was one of the chemists who tried to isolate potassium and sodium. Davy’s first attempt was unsuccessful because he passed an electric current through a water solution of mineral alkali (a sodium compound). Although the electricity successfully isolated the sodium, it then immediately reacted with the water in the solution. Following this Davy then passed an electric current through a sample of melted mineral alkali. This time he was successful and officially isolated sodium on October 6th 1807.

HOW DOES YOUR BODY USE SODIUM?

Around 0.15% of an average person’s bodyweight is sodium the majority of which is stored in the blood and fluid that surrounds the body’s cells. It has a number of roles in the body which include:
- Assisting with the metabolism of carbohydrates and proteins.
- Keeping minerals soluble in the blood.
- Keeping your joints flexible.
- Maintaining a proper fluid balance.
- Maintaining blood volume.
- Maintaining regular heartbeats.
- Regulating blood pressure.
- Supporting major organs including the liver, pancreas and spleen.
- Supporting muscle contractions.
- Supporting nerve transmissions.

HOW MUCH SODIUM DO YOU NEED?

In the UK the recommended daily allowance (RDA) for sodium is 1600mg for both men and women. This requirement does not fluctuate with age and remains constant throughout your life. However, if you have high blood pressure it is recommended that you keep your sodium intake below 1500mg.

WHICH FOODS CONTAIN SODIUM?

Sodium is most commonly associated with table salt. Whilst table salt is one of the richest sources of sodium it is not the only way to consume this micronutrient. The list below highlights some good sodium food choices:
- Cheddar Cheese:- 610mg per 100g.
- Olives:- 1800mg per 100g.
- Prawns:- 1590mg per 100g.
- Salted Butter:- 840mg per 100g.
- Table Salt:- 38850mg per 100g.
- whole grain Bread:- 540mg per 100g.

WHAT ARE THE SYMPTOMS OF GETTING TOO MUCH SODIUM?

Unlike many of the micronutrients I have covered on this blog, getting too much sodium is a problem for many people. Since many people’s diets contain high levels of processed foods (which have lots of added salt) they often consume much more than the recommended 1600mg per day and the tolerable upper limit of 2300mg per day. Furthermore, certain diseases can raise sodium levels in the body. High levels of sodium in the body are known as hypernatremia which has a number of negative symptoms including:
- Fluid retention.
- Increased blood pressure.
- Increased heart disease risk.
- Increased kidney disease risk.
- Swelling of the legs and hands.

WHAT ARE THE SYMPTOMS OF NOT GETTING ENOUGH SODIUM?

Low levels of sodium in the body (hyponatremia) are extremely rare. In most cases hyponatremia is caused by certain diseases, certain medications, diarrhea, excessive sweating and vomiting. When it does occur, hyponatremia leads to:
- Confusion.
- Headaches.
- Lethargy.
- Muscle twitching.
- Nausea.

SODIUM SUMMARY

Salt and sodium are often portrayed negatively and seen as nutrients to avoid. However, sodium is essential for the proper functioning of your body. Whilst overdosing on this micronutrient is a big problem if you keep an eye on your intake and cut down on the processed foods you can enjoy the benefits whilst avoiding any negative symptoms.

Now I want to hear from you guys. Do you go out of your way to avoid sodium? Were you aware that it is needed to help your body function properly? Let me know by leaving a comment.

Sources:
Sodium (Chemistry Explained)
Sodium (Na) in Blood (WebMD)
Sodium as a Supplement (Chet Day’s Health and Beyond)
Sodium in Diet Nutrition (New York Times)
Sodium RDA (Anne Collins)

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