A nutrient is a substance required to survive, grow, and reproduce.
Nutrients can be incorporated into cells for metabolic purposes or excreted by cells to create non-cellular structures: such as hair, nails.
Some nutrients can be metabolically converted to smaller molecules in the process of releasing energy, such as for carbohydrates, lipids, proteins, and fermentation products, producing end-products of water and carbon dioxide.
All organisms require water.
Essential nutrients are the energy sources, some of the amino acids that are combined to create proteins, a subset of fatty acids, vitamins and certain minerals.
Ascorbic acid (vitamin C) is essential, meaning it must be consumed in sufficient amounts.
Nutrients may be organic or inorganic.
Organic compounds include most compounds containing carbon, while all other chemicals are inorganic.
Inorganic nutrients include nutrients such as iron, selenium, and zinc, while organic nutrients include, among many others, energy-providing compounds and vitamins.
A classification of nutrient needs of divides nutrients into macronutrients and micronutrients.
Consumed in relatively large amounts, as in grams or ounces are macronutrients:
carbohydrates, fats, proteins, water.
Macronutrients are primarily used to generate energy or to incorporate into tissues for growth and repair.
Micronutrients are needed in smaller amounts as in milligrams or micrograms, and they have subtle biochemical and physiological roles in cellular processes, like vascular functions or nerve conduction.
In the presence of Inadequate amounts of essential nutrients, or diseases that interfere with absorption, a nutrient deficient state compromises growth, survival and reproduction.
Advisories for dietary nutrient intakes, such as the United States Dietary Reference Intake, are based on deficiency outcomes,
and provide macronutrient and micronutrient guides for both lower and upper limits of intake.
Macronutrients and micronutrients in significant content are required by regulations to be displayed on food product labels.
Nutrients in larger quantities than the body needs may have harmful effects.
Edible plants also contain compounds, phytochemicals, which have unknown effects on disease or health, including a class with non-nutrient status called polyphenols.
The chemical elements consumed in the largest quantities are carbon, hydrogen, nitrogen, oxygen, phosphorus, and sulphur (CHNOPS0.
The chemical compounds consumed in the largest quantities and provide energy are classified as carbohydrates, proteins, and fats.
Water must be also consumed in large quantities but does not provide caloric value.
Calcium, sodium, potassium, magnesium, and chloride ions, along with phosphorus and sulfur, are macronutrients, required in large quantities compared to micronutrients.
Micronutrients: vitamins and other minerals are often described as trace or ultratrace minerals.
Macronutrients provide energy:
Carbohydrates, are compounds made up of types of sugar, classified according to their number of sugar units:
monosaccharides (such as glucose and fructose),
disaccharides (such as sucrose and lactose),
oligosaccharides,
and polysaccharides (such as starch, glycogen, and cellulose).
Proteins are organic compounds that consist of amino acids joined by peptide bonds.
The body cannot manufacture some of the amino acids, termed essential amino acids: the diet must supply them.
Proteins are broken down by proteases back into free amino acids, by digestion.
Fats consist of a glycerin molecule with three fatty acids attached.
Fatty acids contain a -COOH group attached to unbranched hydrocarbon chains connected by single bonds alone (saturated fatty acids) or by both double and single bonds (unsaturated fatty acids).
Fats are needed for construction and maintenance of cell membranes, to maintain a stable body temperature, and to sustain the health of skin and hair.
The body does not manufacture certain fatty acids, essential fatty acids, they must be obtained through one’s diet.
Kilocalories per 1 gram
Protein 4
Carbohydrate 4
Alcohol 7
Fat 9
Micronutrients
Dietary minerals are generally trace elements, salts, or ions such as copper and iron.
Some minerals are essential to human metabolism.
Vitamins are organic compounds essential, and usually act as coenzymes or cofactors for various proteins in the body.
An essential nutrient required for normal physiological function that cannot be synthesized in the body, either at all or in sufficient quantities and must be obtained from the diet.
Essential nutrients are required various cellular metabolic processes and for the maintenance and function of tissues and organs.
Essential nutrients: nine amino acids, two fatty acids, thirteen vitamins and fifteen minerals.
There are, in addition, several other molecules that are considered conditionally essential nutrients since they are indispensable in certain developmental and pathological states.
Essential amino acids:
Out of the twenty standard protein-producing amino acids, nine cannot be endogenously synthesized by humans: phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine.
Only two fatty acids are known to be essential for humans: alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid).
Vitamins are organic molecules essential for an organism that are not classified as amino acids or fatty acids.
Vitamins commonly function as enzymatic cofactors, metabolic regulators or antioxidants.
Humans require thirteen vitamins in their diet.
Vitamins A, C, D, E, K, thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), vitamin B6 (e.g., pyridoxine), biotin (B7), folate (B9), and cobalamin (B12).
The requirement for vitamin D is conditional, as people who get sufficient exposure to ultraviolet light, either from the sun or an artificial source, synthesize vitamin D in the skin.
Minerals are exogenous chemical elements indispensable for life.
The four elements: carbon, hydrogen, oxygen, and nitrogen, which are essential for life, but are so plentiful in food and beverages, that they are not considered nutrients.
For carbon, hydrogen, oxygen, and nitrogen there are no recommended intakes for these as minerals.
The need for nitrogen is fulfilled by protein, which is composed of nitrogen-containing amino acids.
Sulfur is essential, but does not have a recommended intake.
Recommended intakes exist for the sulfur-containing amino acids methionine and cysteine.
The essential nutrient elements listed in order of recommended dietary allowance/: are potassium, chloride, sodium, calcium, phosphorus, magnesium, iron, zinc, manganese, copper, iodine, chromium, molybdenum, selenium and cobalt.
Choline is an essential nutrient.
Diets deficient in choline are associated with the development of fatty liver, liver damage, and muscle damage.
Choline was not initially classified as essential because the human body can produce choline in small amounts through phosphatidylcholine metabolism.
Conditionally essential nutrients refer to organic molecules that can normally be synthesized by an organism, but under certain conditions in insufficient quantities: premature birth, limited nutrient intake, rapid growth, and certain disease states.
Conditionally essential nutrients: Inositol, taurine, arginine, glutamine and nucleotides.
Nucleotides are classified as conditionally essential and are particularly important in neonatal diet and metabolism.
Non-essential nutrients are substances within foods that can have a significant impact on health: Insoluble dietary fiber is not absorbed in the human digestive tract, but is important in maintaining the bulk of a bowel movement to avoid constipation; Soluble fiber metabolized by bacteria residing in the large intestine, serving a prebiotic function with claims for promoting healthy intestinal bacteria.
The bacterial metabolism of soluble fiber produces short-chain fatty acids like butyric acid, which may be absorbed into intestinal cells as a source of food energy.
Ethanol (C2H5OH) is not an essential nutrient.
Ethanol does supply approximately 29 kilojoules (7 kilocalories) of food energy per gram.
For spirits (vodka, gin, rum, etc.) a standard serving in the United States is 44 millilitres (1+1⁄2 US fluid ounces), which at 40% ethanol (80 proof) would be 14 grams and 410 kJ (98 kcal). (At 50% alcohol, 17.5 g and 513 kJ (122.5 kcal).).
Wine and beer contain a similar amount of ethanol in servings of 150 and 350 mL (5 and 12 US fl oz), respectively, but these beverages also contribute to food energy intake from components other than ethanol.
A 150 mL (5 US fl oz) serving of wine contains 420 to 540 kJ (100 to 130 kcal). A 350 mL (12 US fl oz) serving of beer contains 400 to 840 kJ (95 to 200 kcal).
A NHANES 2013–2014 surveys, women ages 20 and up consume on average 6.8 grams of alcohol per day and men consume on average 15.5 grams per day.
Alcoholic beverages are considered empty calorie foods because, while providing energy, they contribute no essential nutrients.
Phytochemicals include all nutritional and non-nutritional components of edible plants.
Other nutritional constituents in plant foods: provitamin A carotenoids, diverse polyphenols, flavonoids, resveratrol, and lignans.
Nutrient deficiency can be due to a number of causes including an inadequacy in nutrient intake, or any of several conditions that interfere with the utilization of a nutrient.
Various conditions that can interfere with nutrient utilization include: impaired nutrient absorption, increased need for a nutrient, conditions of nutrient destruction, and conditions that cause greater nutrient excretion.
Nutrient toxicity refers to excess consumption of a nutrient causing harm.
Recommended dietary intake levels of essential nutrients are based on the minimum level needed to maintain a defined level of a nutrient.
World Health Organization: recommended dietary intake is a basal requirement to indicate the level of intake needed to prevent pathologically relevant and clinically detectable signs of a dietary inadequacy.
In setting human nutrient guidelines, organizations do not necessarily agree on amounts needed to avoid deficiency or maximum amounts to avoid the risk of toxicity.
Macronutrients
Nutrient RDI DV UL
Calories 2000 2000 N/A
Fat N/A 78g N/A
Saturated Fat N/A 20g N/A
Cholesterol N/A 300mg N/A
Carbs 130g 300g N/A
Fiber 38g 28g N/A
Sugar N/A 50g N/A
Protein 56g 50g N/A
Vitamins
Nutrient RDI DV UL
Vitamin A 900μg 3000IU 3000μg
Vitamin B1 1.2mg 1.2mg N/A
Vitamin B2 1.3mg 1.3mg N/A
Vitamin B3 16mg 16mg 35mg
Vitamin B5 N/A 5mg N/A
Vitamin B6 1.3mg 1.7mg 100mg
Vitamin B9 400μg 400μg 1000μg
Vitamin B12 2.4μg 2.4μg N/A
Vitamin C 90mg 90mg 2000mg
Vitamin D N/A 20μg N/A
Vitamin E 15mg 15mg 1000mg
Vitamin K N/A 120mg N/A
Choline N/A 550mg 3500mg
Lycopene N/A N/A N/A
Lutein+zeazanthin N/A N/A N/A
Minerals
Nutrient RDI DV UL
Calcium N/A 1300mg 2500mg
Copper 0.9mg 0.9mg 10mg
Iodine 150μg N/A 1100μg
Iron 8mg 18mg 45mg
Magnesium 400mg 420mg N/A
Manganese N/A 2.3mg 11mg
Phosphorus 700mg 1250mg 4000mg
Potassium 4700mg 4700mg N/A
Selenium 55μg 55μg 400μg
Sodium 1500mg 2300mg N/A
Zinc 11mg 11mg 40mg
Ash N/A N/A N/A
Water N/A N/A N/A
Fatty Acids
Nutrient RDI
Omega 3s 1600mg
Omega 6s17000mg
Amino Acids
NutrientRDI
Tryptophan280mg
Histidine700mg
Threonine1050mg
Isoleucine1400mg
Lysine2100mg
Leucine2730mg
Methionine 728mg
Cystine287mg
Phenylalanine875mg
Tyrosine875mg
Valine 1820mg
Recommended Dietary Allowances; higher for adults than for children, and may be even higher for women who are pregnant or lactating.