Nutrient

Types of human nutrients

Macronutrients are defined in several different ways.

• The sulfur.
• The classes of oxygen also must be consumed in large quantities, but are not always considered "food" or "nutrients".
• macrominerals.

The remaining vitamins, minerals, or elements, are called micronutrients because they are required in relatively small quantities.

Substances that provide energy

• cellulose).

• proteases back into free amino acids.

• Fats consist of a essential fatty acids) and the diet must supply these.

Fat has an energy content of 9 kcal/g (~37.7 kJ/g); Ethanol (grain alcohol) has an energy content of 7 kcal/g (~29.3 kJ/g).^{[citation needed]}

Substances that support metabolism

• Dietary minerals are generally trace elements, salts, or ions such as copper and iron. Some of these minerals are essential to human metabolism.

• coenzymes or cofactors for various proteins in the body.

• Water is an essential nutrient and is the solvent in which all the chemical reactions of life take place.

Nutrients and plants

Main articles: Fertilizer

 

The chemical elements consumed in the greatest quantities by plants are diatomic molecules of nitrogen and (especially) oxygen are often used.

Other chemical elements are also necessary to carry out various life processes and build structures; see fertilizer and micronutrient for more information.

Some of these are considered macronutrients in certain organisms. The acronym C. HOPKiN'S CaFe Mg (to be used as C. Hopkins coffee mug) is used by some students to remember the list as: Carbon, Hydrogen, Oxygen, Phosphorus, Potassium (K), Nitrogen, Sulfur, Calcium, Iron (Fe), and Magnesium (Mg). Silicon, chloride, sodium, copper, zinc, and molybdenum are sometimes also included, but are in other cases considered micronutrients.

Oversupply of plant nutrients in the environment can cause excessive plant and water pollution from sewage or runoff from farms (carrying excess agricultural fertilizer). Nitrogen and phosphorus are most commonly the limiting factor in growth, and thus the most likely to trigger eutrophication when introduced artificially.

Essential and non-essential nutrients

Main article: Essential nutrient

Nutrients are frequently categorized as essential or nonessential. Essential nutrients are unable to be synthesized internally (either at all, or in sufficient quantities), and so must be consumed by an organism from its environment.

For humans, these include Oxygen and water are also essential for human survival, but are generally not considered "food" when consumed in isolation.

Humans can derive energy from a wide variety of fats, ethanol, and can synthesize other needed amnio acids from the essential nutrients.

Non-essential nutrients can still have a significant impact on health, whether beneficial or toxic. For example, most dietary fiber is not absorbed by the human digestive tract, but is important in digestion and absorption of otherwise harmful substances. Interest has recently increased in phytochemicals, which include many non-essential nutrients which may have health benefits.

References

The references in this article would be clearer with a different or consistent style of citation, footnoting, or external linking.

• Donatelle, Rebecca J. "Health: The Basic"

See also

• Ecological sanitation
• Nutrient density