Sea salt, like any other, is mainly composed of sodium chloride. The content of NaCl in sea salt ranges from 94 to 98%. What distinguishes it from different types of salt is the extraction method and the content of small amounts of mineral ingredients. If you want to learn more about sea salt or are interested in the potential benefits and dangers associated with its consumption, I invite you to read the article.
How is sea salt formed?
Saltwater is needed to obtain sea salt. Water salinity varies in different regions and depends on many factors. It determines the amount of dissolved solids in a specified volume of seawater. The presence of chlorides, mainly sodium chloride, determines salinity. It is this property of seawater that we use for salt production. 
Semi-enclosed seas of tropical latitudes (e.g., the Mediterranean, Tyrrhenian, Red, Black, Persian Gulf) have higher salinity than oceanic waters or semi-enclosed seas located in temperate and polar latitudes (e.g., the Baltic, North, White, Norwegian seas). 
For example, the salinity of the Baltic Sea near the Polish coast is 7-8 per mille. The exact value for the Red Sea is 41-45 per mile. 
Therefore, we produce sea salt in regions with low precipitation and many sunny days throughout the year. Sea salt production occurs in artificially created, shallow basins called salinas. They are made near saline water reservoirs. Under the influence of the sun and wind, there is strong evaporation from the water’s surface. As a result, the water volume decreases, and sodium chloride precipitates. The salt is then collected and packaged.
In the marshy areas of Camargue (France), near the mouth of the Rhone, ponds created during Roman times are used to extract sea salt. Sea salt has been harvested in the Sicilian town of Trapani for centuries, where artificial brine basins exist. Sea salt is also produced in the British Isles, China, India, Spain, Portugal, the Dead Sea, the Red Sea, and many other places.
What else does sea salt contain besides sodium chloride?
Although the main ingredient in sea salt, as in any other, is sodium chloride (94-98%), it also contains mineral components. According to scientists, in 100 grams of sea salt, we will find:
- 92.75 milligrams of magnesium,
- 65.01 milligrams of sulfur,
- 32.38 milligrams of potassium,
- 15.79 milligrams of calcium.
So why shouldn’t we treat salt as a source of these elements? Because these are trace amounts. For example, the RDA (Recommended Daily Allowance) for an adult male for magnesium is 420 mg daily. Taking into account WHO recommendations (5g of salt per day), throughout the day with sea salt, we will only provide the body with 4.64 mg of magnesium.
If we wanted to meet the magnesium requirement using sea salt, we would have to consume nearly 500g of salt per day, exceeding the lethal sodium chloride consumption dose. The limit for this component is 3g/kg of body weight. Consuming amounts of salt exceeding 100g (this value is much lower for children) can lead to brain edema and, as a result, death.
Polluted seas = polluted salt?
According to Spanish scientists from the University of Alicante, the pollution of seas and oceans can affect products derived from these reservoirs. When consuming fish or salt, microplastics can enter our bodies.  Researchers in India drew similar conclusions. Microplastics, including nylon, polypropylene, and polyethylene, were detected in 25 sea salt samples. 
Colors and shades of sea salt
Sea salt can take on different colors, from white to grayish. It depends on the region and the concentration of elements. The dark color of sea salt indicates a higher concentration of elements but also more pollution. 
Effect of sea salt on health
In South Korea, an international group of scientists conducted a study on rats, published in Food & Nutrition research in 2016. Five groups of male Dahl rats were fed rat food supplemented with various amounts and types of salt- two groups received food with sea salt and two with refined salt. The control group received regular rat food. According to the analysis, sea salt contained 85.7% sodium chloride and calcium, potassium, magnesium, and trace amounts of iron, manganese, and zinc. Refined salt contained 99.9% sodium chloride. The rats received food for 15 weeks. Afterward, various parameters of the rats were analyzed. In the group of rats consuming food with the addition of sea salt, lower hypertension and less heart and kidney damage were found compared to the group receiving food with refined salt. 
Why did sea salt cause lower hypertension in rats? The mechanism of this still needs to be fully understood by scientists. They believe that the mineral components contained in sea salt, which have antihypertensive effects, contributed to this. However, they emphasize the need for further research to clarify how sea salt lowers blood pressure. Further studies are also needed to determine whether this mechanism works in humans. 
According to experts from the National Center for Nutrition Education, sea salt is no healthier than other types of salt. The content of mineral components is too small to treat salt as their source. 
The WHO took a similar position on sea salt. According to this organization, the claim that sea salt is healthier than table salt is a misconception. 
Sodium chloride content in different types of salt 
- Sea salt: 94.0-98.0%
- White table salt: 97.1%
- Himalayan salt: 97.5%
- Rock table salt, gray, pink: 97.0%
- Dead Sea salt: 99.0%
- Hawaiian salt, red, black, green, white: 97.5%
- Pyramid salt from India: 98.7%
Application of sea salt
In addition to using sea salt to season dishes, it is often used in the cosmetics industry. It has detoxifying and exfoliating skin properties. On the market, you can find body peels and scrubs with the addition of sea salt. Baths with sea salt relax, relieve muscle pain, and improve blood circulation. Many sanatoriums and SPAs use sea salt benefits as well.
Frequently asked questions:
The primary difference between these two types of salt is the method of obtaining them. Besides, sea salt has a lower concentration of sodium chloride.
Table salt originated similarly to how sea salt is now obtained – through the evaporation of saline waters. However, this process took place many millions of years ago, while sea salt is produced in this way today. It’s worth noting that millions of years ago, seas and oceans were free from pollution caused by the development of civilization.
It’s difficult to answer this question unequivocally. The main sea salt ingredient is sodium chloride, which is essential in our bodies. However, an excess of this component can hurt our health (above 1500 mg/day). It’s important to remember that sea salt can be contaminated with microplastic particles, and the concentration of valuable elements is too low to benefit health.
Sea salt in a solution with water (about 2%) is used for clearing and moisturizing nasal passages.
Many preparations are available, both in hypertonic and isotonic solutions (also for children). It is considered a safe way to combat cold symptoms and their effects on nasal mucosa.
It’s used both for hair care and styling. It gives hair volume and emphasizes its natural curl. Using cosmetics with sea salt helps achieve a beachy wave effect on hair.
Salt is a product whose consumption we should monitor. The belief in the health benefits of sea salt is probably associated with the fact that it contains valuable elements. However, their quantity is trace. We should not overlook the fact that it might have microplastic. Specialists emphasize that excessive sodium consumption can lead to many health consequences . Therefore, instead of wondering which type of salt is healthier, we should aim for optimal consumption of this product. The reference values developed by EFSA are 5 grams per day (one teaspoon). Remember that in addition to the salt added during meal preparation, we also consume salt added during the production of many food products.
- Tomassi-Morawiec Hanna, Czapowski Grzegorz, 2012, Sól nasza powszednia. Magazyn Polskiej Akademii Nauk 1(29).
- Megan N. Biango-Daniels, Kathie T.Hodge, 2018, Sea salts as a potential source of food spoilage fungi. Food Microbiology 69, strona 89-95.
- Eui-Seong Park, Ting Yu, Kiho Yang, Shinil Choi, Seung-Min Lee, Kun-Young Park, 2020, Cube natural sea salt ameliorates obesity in high fat diet- induced obese mice and 3T3-L1 adipocytes. Scientific Reports 10, strona 1-16.
- Maria E. Iniguez, Juan A. Conesa, Andreas Fullana, 2017, Microplastics in Spanish table salt. Scientific Reports 7, strona 1-7.
- Anna Stephanie Mengga Dapa Taka, Christina Olly Lada, Anita Lidesna, Shinta Amat, 2023, Differences in microplastic content in commercial salt and salt at the Semiringkai coastal local center in Kupang City and Kupang regency. Indian Journal of Community Medicine 48, strona 238-240.
- Pobrane z: Anna Wojtasik, Sól himalajska czy morska- która jest zdrowsza?
- Bog-Hieu Lee, Ae-Ri Yang, Mi Young Kim, Sara McCurdy, William A. Boisvert, 2016, Natural sea salt consumption confers protection against hypertension and kidney damage in Dahl salt- sensitive rats. Food&Nutrition research 61.
- Saoraya Chanmuang, Bo-Min Kim, Su-Yeon Gu, Ye- Jin Son, Huong-Giang Le, Young- Do Nam, Eun-Ji Song, Kyung-Sik Ham, Hyun-Jin Kim, 2022, Effects of sea salt intake on metabolites, steroid hormones and gut microbiota in rats. Plos One 17(8).
- Normy żywienia dla populacji Polski i ich zastosowanie, pod redakcją Mirosława Jarosza, Ewy Rychlik, Katarzyny Stoś, Jadwigi Charzewskiej, 2020.
- WHO, Guideline: Sodium intake for adults and children, 2012.
- Bajkiewicz-Grabowska, E., Mikulski, Z., 2008, Hydrologia Ogólna. Warszawa. Wydawnictwo Naukowe PWN. strona 260-262.