Mineral salts

Generality

Mineral salts are inorganic compounds (free of organic carbon) that play a fundamental role in the functioning of all living organisms, including humans.

Although mineral salts constitute a relatively small part of the human body (about 6-7% of body weight), they are part of the constitution of many tissues and represent essential factors for biological functions and growth.

The mineral salts are present in the human body both linked to organic molecules and in inorganic form in two different states:

in the solid state: as crystals (in bones and teeth);
in solution: both in ionized and non-ionized form (in blood and in biological liquids).

The mineral salts can pass from one state to another as happens for example for calcium, which in the case of hypocalcemia, is moved from the bones (where it is in crystalline form) to plasma (in ionic form).

Classification

Depending on the daily requirement, in human nutrition, mineral salts are classified into three main groups:

macroelements
trace elements
Micronutrients

macroelements

This category includes all those mineral salts that are present in fair quantities in the body.

The macroelements include: calcium, phosphorus, magnesium, sulfur, sodium, potassium, chlorine. The daily need for these mineral salts is in the order of grams or tenths of a gram.

Element	Percentage in the Human Body
Oxygen	65%
Carbon	18.5
Hydrogen	9.5
Nitrogen	3.2
Football	1.5
Phosphorus	1
Potassium	0.4
Sulfur	0.3
Sodium	0.2
Chlorine	0.2
Magnesium	0.3
Trace elements: boron, chromium, cobalt, copper, fluorine, iodine, iron, manganese, molybdenum, selenium, silicon, tin, vanadium, zinc	<1%

Trace elements and microelements

The mineral salts of this category are present only in traces in the body; therefore, their daily requirement is in the order of milligrams or even micrograms (millionths of a gram).

Trace elements are considered to be mineral salts characterized by a daily requirement of less than 200 mg;
The mineral salts characterized by a daily requirement of less than 100 mg are considered as micro-nutrients.

In recent years, thanks to sophisticated analytical techniques, it has been possible to highlight the various functions that trace elements exert in the body, enhancing their nutritional importance.

The trace elements can in turn be divided into:

essential trace elements (iron, copper, zinc, iodine, selenium, chromium, cobalt, fluorine): essential minerals for the body, are part of organic molecules responsible for vital roles; their lack would compromise important physiological functions
probably essential trace elements (silicon, manganese, nickel, vanadium);
potentially toxic trace elements (arsenic, lead, cadmium, mercury, aluminum, lithium, strontium): they probably perform important functions at very low concentrations.

Bioavailability

To assess the essentiality or toxicity of an element, it is necessary to evaluate its bioavailability, that is the amount ingested that is actually absorbed, transported to the site of action and converted into the active form.

The bioavailability of an element is influenced by several factors interacting with each other, some intrinsic to the organism (species, genotype, age, sex, physiological state, nutritional and health status, intestinal microflora, etc.), other extrinsic (chemical form of the mineral, presence of anti-nutritional factors that limit absorption or, conversely, favor it).

Excess and Deficiency

The toxicity of minerals depends essentially on the amount of them reaching the body, so they are all potentially toxic at high doses.

A varied and rational diet is alone able to satisfy the needs of mineral salts; however, for some of them such as calcium, iron and iodine deficiency syndromes can be easily met, especially in particular physiological conditions such as pregnancy.

Functions of Mineral Salts

Ultimately, mineral salts perform numerous control, regulation and structure functions.

Functions performed by more minerals are osmotic regulation and maintenance of acid-base balance.

ELEMENT	FUNCTION	FOOD THAT CONTAINS IT
SOCCER (Ca)	Forms the rigid material of bones and teeth. Regulates blood clotting and muscle functioning. If the bones are missing they become weaker.	Milk and derivatives, green vegetables, legumes, cereals
PHOSPHORUS (P)	Together with calcium it contributes to the formation of the rigid material of bones and teeth. It is important for the energy transformations that take place in the cells.	Milk, meat, fish, eggs, liver, cereals, legumes.
POTASSIUM (K)	Regulates exchanges between cells and body fluids.	It is present in all foods, especially cereals, vegetables and meat.
SODIUM (Na)	Regulates exchanges between cells and body fluids. It is useful for water balance in the body.	It is the constituent, together with chlorine, of cooking salt.
CHLORINE (Cl)	It is important for the formation of gastric juice.	It is the constituent, together with sodium, of cooking salt.
MAGNESIUM (Mg)	Implement some chemical reactions in the body.	Cereals, legumes, almonds, walnuts.
IRON (Fe)	Become part of the hemoglobin molecule that constitutes red blood cells. It carries oxygen and carbon dioxide in the blood. If it is missing, there are forms of anemia.	Meat, liver, eggs, legumes, cereals, vegetables.
SULFUR (S)	Enter the constitution of proteins.	Meat, fish, milk and dairy products, legumes, cereals.
MANGANESE (Mn)	Implement some chemical reactions in the body.	Wholemeal flour, nuts, cereals, green vegetables, meat.
IODIO (I)	Regulates the activity of the thyroid gland. If it is missing, the gland is enlarged and the characteristic goiter.	Sea salt, fish and marine mollusks, vegetables, eggs.