Essential Nutrients: Functions and Sources for Human Health

Essential Nutrients for Human Health

Nutrients are the biomolecules that make up our bodies. They are categorized as follows:

• Carbohydrates: Cereals, pasta, bread.
• Proteins: Foods derived from animals.
• Mineral salts: Found in all foods.
• Lipids: Oil, butter, bacon.
• Water: Consumed through drinks and food.
• Vitamins: Vegetables and fresh fruit.

Carbohydrates (Glucids)

Carbohydrates provide energy and are divided into two main groups:

• Simple carbohydrates (sugars): These have a sweet taste, are crystalline, and are soluble in water. They include:
  • Monosaccharides: Such as glucose and fructose.
  • Disaccharides: Formed by the bonding of two monosaccharides, such as sucrose and lactose.
• Complex carbohydrates: These are not sweet or crystalline. They are formed by the bonding of many molecules found in simple carbohydrates. The most important complex carbohydrates in our diets are starch and cellulose, which is contained in vegetable fiber.

Lipids

Lipids are very diverse and are not soluble in water. They are divided into three main groups:

• Fats: High in energy and can be saturated or unsaturated. Saturated fats are mostly of animal origin, while unsaturated fats are mostly of plant origin.
• Membrane lipids: These form the structures of cell membranes and cell organelles, such as phospholipids and cholesterol.
• Lipids with regulatory functions: Includes vitamins A and D, and sexual hormones.

Proteins

Proteins are the most important structural molecules and are formed by amino acids. They perform many tasks, including:

• Forming structures such as hair and nails.
• Transporting oxygen.
• Defending against infections.
• Responsible for muscle contraction.
• Regulating biological responses.

Our body can produce 12 of the 20 known amino acids; the remaining eight are referred to as essential amino acids. Proteins found in eggs, milk, and other animal sources contain a balanced amount of all amino acids, whereas plant proteins tend to be deficient in some.

Mineral Salts

Mineral salts are inorganic substances with various functions. Some are structural, making up bones and teeth, while others help regulate cellular metabolic reactions. They are abundant in fruits and vegetables.

Water

Water is the most common molecule in our bodies, making up around 63% of our body mass. It is essential for carrying out metabolic reactions. We need to drink approximately 2.5 liters of water every day.

Vitamins

Our body needs vitamins in very small quantities to function correctly. There are two types:

• Fat-soluble vitamins: Soluble in fat and stored in our liver (e.g., vitamins A and D).
• Water-soluble vitamins: These are not stored in our body (e.g., vitamins B and C).