Vitamin in the context of Tempeh

A nutrient is a substance used by an organism to survive, grow and reproduce. The requirement for dietary nutrient intake applies to animals, plants, fungi and protists. Nutrients can be incorporated into cells for metabolic purposes or excreted by cells to create non-cellular structures such as hair, scales, feathers, or exoskeletons. Some nutrients can be metabolically converted into smaller molecules in the process of releasing energy such as for carbohydrates, lipids, proteins and fermentation products (ethanol or vinegar) leading to end-products of water and carbon dioxide. All organisms require water. Essential nutrients for animals are the energy sources, some of the amino acids that are combined to create proteins, a subset of fatty acids, vitamins and certain minerals. Plants require more diverse minerals absorbed through roots, plus carbon dioxide and oxygen absorbed through leaves. Fungi live on dead or living organic matter and meet nutrient needs from their host.

Different types of organisms have different essential nutrients. Ascorbic acid (vitamin C) is essential to humans and some animal species but most other animals and many plants are able to synthesize it. 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, protein, fats, sugars and vitamins.

Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin and contains essential nutrients such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ingested by an organism and assimilated by the organism's cells to provide energy, maintain life, or support growth. Different species of animals have different feeding behaviours that satisfy the needs of their metabolisms and have evolved to fill specific ecological niches within specific geographical contexts.

Omnivorous humans are highly adaptable and have adapted to obtaining food in many different ecosystems. Humans generally use cooking to prepare food for consumption. The majority of the food energy required is supplied by the industrial food industry, which produces food through intensive agriculture and distributes it through complex food processing and food distribution systems. This system of conventional agriculture relies heavily on fossil fuels, which means that the food and agricultural systems are one of the major contributors to climate change, accounting for as much as 37% of total greenhouse gas emissions.

Food energy is chemical energy that animals derive from food to sustain their metabolism and muscular activity. This is usually measured in joules or calories.

Most animals derive most of their energy from aerobic respiration, namely combining the carbohydrates, fats, and proteins with oxygen from air or dissolved in water. Other smaller components of the diet, such as organic acids, polyols, and ethanol (drinking alcohol) may contribute to the energy input. Some diet components that provide little or no food energy, such as water, minerals, vitamins, cholesterol, and fiber, may still be necessary for health and survival for other reasons. Some organisms have instead anaerobic respiration, which extracts energy from food by reactions that do not require oxygen.

Micronutrients are essential chemicals required by organisms in small quantities to perform various biogeochemical processes and regulate physiological functions of cells and organs. By enabling these processes, micronutrients support the health of organisms throughout life.

For humans, micronutrients typically take one of three forms: vitamins, trace elements, and dietary minerals. Human micronutrient requirements are in amounts generally less than 100 milligrams per day, whereas macronutrients are required in gram quantities daily. Deficiencies in micronutrient intake commonly result in malnutrition.

Among animals which produce eggs, the yolk (/ˈjoʊk/; also known as the vitellus) is the nutrient-bearing portion of the egg whose primary function is to supply food for the development of the embryo. Some types of egg contain no yolk, for example because they are laid in situations where the food supply is sufficient (such as in the body of the host of a parasitoid) or because the embryo develops in the parent's body, which supplies the food, usually through a placenta. Reproductive systems in which the mother's body supplies the embryo directly are said to be matrotrophic; those in which the embryo is supplied by yolk are said to be lecithotrophic. In many species, such as all birds, and most reptiles and insects, the yolk takes the form of a special storage organ constructed in the reproductive tract of the mother. In many other animals, especially very small species such as some fish and invertebrates, the yolk material is not in a special organ, but inside the egg cell.

As stored food, yolks are often rich in vitamins, minerals, lipids and proteins. The proteins function partly as food in their own right, and partly in regulating the storage and supply of the other nutrients. For example, in some species the amount of yolk in an egg cell affects the developmental processes that follow fertilization.

A staple food, food staple, or simply staple, is a food that is eaten often and in such quantities that it constitutes a dominant portion of a standard diet for an individual or a population group, supplying a large fraction of energy needs and generally forming a significant proportion of the intake of other nutrients as well. For humans, a staple food of a specific society may be eaten as often as every day or every meal, and most people live on a diet based on just a small variety of food staples. Specific staples vary from place to place, but typically are inexpensive or readily available foods that supply one or more of the macronutrients and micronutrients needed for survival and health: carbohydrates, proteins, fats, minerals and vitamins. Typical examples include grains (cereals and legumes), seeds, nuts and root vegetables (tubers and roots). Among them, cereals (rice, wheat, oat, maize, etc.), legumes (lentils and beans) and tubers (e.g. potato, taro and yam) account for about 90% of the world's food calorie intake.

Early agricultural civilizations valued the crop foods that they established as staples because, in addition to providing necessary nutrition, they generally are suitable for storage over long periods of time without decay. Such nonperishable foods are the only possible staples during seasons of shortage, such as dry seasons or cold temperate winters, against which times harvests have been stored. During seasons of surplus, wider choices of foods may be available.

A pseudocereal or pseudograin is one of any non-grasses that are used in much the same way as cereals (true cereals are grasses). Pseudocereals can be further distinguished from other non-cereal staple crops (such as potatoes) by their being processed like a cereal: their seed can be ground into flour and otherwise used as a cereal. Prominent examples of pseudocereals include amaranth (love-lies-bleeding, red amaranth, Prince-of-Wales-feather), quinoa, and buckwheat. The pseudocereals have a good nutritional profile, with high levels of essential amino acids, essential fatty acids, minerals, and some vitamins. The starch in pseudocereals has small granules and low amylose content (except for buckwheat), which gives it similar properties to waxy-type cereal starches. The functional properties of pseudocereals, such as high viscosity, water-binding capacity, swelling capability, and freeze-thaw stability, are determined by their starch properties and seed morphology. Pseudocereals are gluten-free, and they are used to make 100% gluten-free products, which has increased their popularity.

In the context of nutrition, a mineral is a chemical element. Some "minerals" are essential for life, but most are not. Minerals are one of the four groups of essential nutrients; the others are vitamins, essential fatty acids, and essential amino acids. The five major minerals in the human body are calcium, phosphorus, potassium, sodium, and magnesium. The remaining minerals are called "trace elements". The generally accepted trace elements are iron, chlorine, cobalt, copper, zinc, manganese, molybdenum, iodine, selenium, and bromine; there is some evidence that there may be more.

The four organogenic elements, namely carbon, hydrogen, oxygen, and nitrogen (CHON), that comprise roughly 96% of the human body by weight, are usually not considered as minerals (nutrient). In fact, in nutrition, the term "mineral" refers more generally to all the other functional and structural elements found in living organisms.

Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits, berries and vegetables. It is also a generic prescription medication and in some countries is sold as a non-prescription dietary supplement. As a therapy, it is used to prevent and treat scurvy, a disease caused by vitamin C deficiency.

Vitamin C is an essential nutrient involved in the repair of tissue, the formation of collagen, and the enzymatic production of certain neurotransmitters. It is required for the functioning of several enzymes and is important for immune system function. It also functions as an antioxidant. Vitamin C may be taken by mouth or by intramuscular, subcutaneous or intravenous injection. Various health claims exist on the supposition that moderate vitamin C deficiency increases disease risk, such as for the common cold, cancer or COVID-19. There are also claims of benefits from vitamin C supplementation in excess of the recommended dietary intake for people who are not considered vitamin C deficient. Vitamin C is generally well tolerated. Large doses may cause gastrointestinal discomfort, headache, trouble sleeping, and flushing of the skin. The United States National Academy of Medicine recommends against consuming large amounts.

Vitamin A is a fat-soluble vitamin that is an essential nutrient. The term "vitamin A" encompasses a group of chemically related organic compounds that includes retinol, retinyl esters, and several provitamin (precursor) carotenoids, most notably β-carotene (beta-carotene). Vitamin A has multiple functions: growth during embryo development, maintaining the immune system, and healthy vision. For aiding vision specifically, it combines with the protein opsin to form rhodopsin, the light-absorbing molecule necessary for both low-light (scotopic vision) and color vision.

Vitamin A occurs as two principal forms in foods: A) retinoids, found in animal-sourced foods, either as retinol or bound to a fatty acid to become a retinyl ester, and B) the carotenoids α-carotene (alpha-carotene), β-carotene, γ-carotene (gamma-carotene), and the xanthophyll beta-cryptoxanthin (all of which contain β-ionone rings) that function as provitamin A in herbivore and omnivore animals which possess the enzymes that cleave and convert provitamin carotenoids to retinol. Some carnivore species lack this enzyme. The other carotenoids do not have retinoid activity.

Human food is food which is fit for human consumption, and which humans willingly eat. Food is a basic necessity of life, and humans typically seek food out as an instinctual response to hunger; however, not all things that are edible constitute as human food.

Humans eat various substances for energy, enjoyment and nutritional support. These are usually of plant, animal, or fungal origin, and contain essential nutrients, such as carbohydrates, fats, proteins, vitamins, and minerals. Humans are highly adaptable omnivores, and have adapted to obtain food in many different ecosystems. Historically, humans secured food through two main methods: hunting and gathering and agriculture. As agricultural technologies improved, humans settled into agriculture lifestyles with diets shaped by the agriculture opportunities in their region of the world. Geographic and cultural differences have led to the creation of numerous cuisines and culinary arts, including a wide array of ingredients, herbs, spices, techniques, and dishes. As cultures have mixed through forces like international trade and globalization, ingredients have become more widely available beyond their geographic and cultural origins, creating a cosmopolitan exchange of different food traditions and practices.

Cell culture or tissue culture is the process by which cells are grown under controlled conditions, generally outside of their natural environment. After cells of interest have been isolated from living tissue, they can subsequently be maintained under carefully controlled conditions. They need to be kept at body temperature (37 °C) in an incubator. These conditions vary for each cell type, but generally consist of a suitable vessel with a substrate or rich medium that supplies the essential nutrients (amino acids, carbohydrates, vitamins, minerals), growth factors, hormones, and gases (CO₂, O₂), and regulates the physio-chemical environment (pH buffer, osmotic pressure, temperature). Most cells require a surface or an artificial substrate to form an adherent culture as a monolayer (one single-cell thick), whereas others can be grown free floating in a medium as a suspension culture. This is typically facilitated via use of a liquid, semi-solid, or solid growth medium, such as broth or agar. Tissue culture commonly refers to the culture of animal cells and tissues, with the more specific term plant tissue culture being used for plants. The lifespan of most cells is genetically determined, but some cell-culturing cells have been 'transformed' into immortal cells which will reproduce indefinitely if the optimal conditions are provided.

In practice, the term "cell culture" now refers to the culturing of cells derived from multicellular eukaryotes, especially animal cells, in contrast with other types of culture that also grow cells, such as plant tissue culture, fungal culture, and microbiological culture (of microbes). The historical development and methods of cell culture are closely interrelated with those of tissue culture and organ culture. Viral culture is also related, with cells as hosts for the viruses.

In nutrition, diet is the sum of food consumed by a person or other organism.The word diet often implies the use of specific intake of nutrition for health or weight-management reasons (with the two often being related). Although humans are omnivores, each culture and each person holds some food preferences or some food taboos. This may be due to personal tastes or ethical reasons. Individual dietary choices may be more or less healthy.

Complete nutrition requires ingestion and absorption of vitamins, minerals, essential amino acids from protein and essential fatty acids from fat-containing food, also food energy in the form of carbohydrate, protein, and fat. Dietary habits and choices play a significant role in the quality of life, health and longevity.