Milligram in the context of "Carat (unit)"

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.

In the deep ocean, marine snow (also known as "ocean dandruff") is a continuous shower of mostly organic detritus falling from the upper layers of the water column. It is a significant means of exporting energy from the light-rich photic zone to the aphotic zone below, which is referred to as the biological pump. Export production is the amount of organic matter produced in the ocean by primary production that is not recycled (remineralised) before it sinks into the aphotic zone. Because of the role of export production in the ocean's biological pump, it is typically measured in units of carbon (e.g. mg C m d). The term was coined by explorer William Beebe as observed from his bathysphere. As the origin of marine snow lies in activities within the productive photic zone, the prevalence of marine snow changes with seasonal fluctuations in photosynthetic activity and ocean currents. Marine snow can be an important food source for organisms living in the aphotic zone, particularly for organisms that live very deep in the water column.

Jaundice, also known as icterus, is a yellowish or, less frequently, greenish pigmentation of the skin and sclera due to high bilirubin levels. Jaundice in adults typically indicates the presence of underlying diseases involving abnormal heme metabolism, liver dysfunction, or biliary-tract obstruction. The prevalence of jaundice in adults is rare, while jaundice in babies is common, with an estimated 80% affected during their first week of life. The most commonly associated symptoms of jaundice are itchiness, pale feces, and dark urine.

Normal levels of bilirubin in blood are below 1.0 mg/dl (17 μmol/L), while levels over 2–3 mg/dl (34–51 μmol/L) typically result in jaundice. High blood bilirubin is divided into two types: unconjugated and conjugated bilirubin.

Micro (Greek letter μ, mu, non-italic) is a unit prefix in the metric system denoting a factor of one millionth (10). It comes from the Greek word μικρός (mikrós), meaning "small".

It is the only SI prefix which uses a character not from the Latin alphabet. In Unicode, the symbol is represented by U+03BC μ GREEK SMALL LETTER MU or the legacy symbol U+00B5 µ MICRO SIGN. The prefix "mc" is also commonly used; for example, "mcg" denotes a microgram (whereas mg denotes a milligram).

Sour gas is natural gas or any other gas containing significant amounts of hydrogen sulfide (H₂S).

Natural gas is usually considered sour if there are more than 5.7 milligrams of H₂S per cubic meter of natural gas, which is equivalent to approximately 4 ppm by volume under standard temperature and pressure. However, this threshold varies by country, state, or even agency or application. For instance, the Texas Railroad Commission considers a sour gas pipeline one that carries gas over 100 ppm by volume of H₂S. However, the Texas Commission on Environmental Quality has historically defined sour gas for upstream operations – which requires permitting, reporting, and possibly additional emission controls – as gas that contains more than 24 ppm by volume. Natural gas that does not contain significant amounts of hydrogen sulfide is called "sweet gas".

Vitamin B₆ is one of the B vitamins, and is an essential nutrient for humans. The term essential nutrient refers to a group of six chemically similar compounds, i.e., "vitamers", which can be interconverted in biological systems. Its active form, pyridoxal 5′-phosphate, serves as a coenzyme in more than 140 enzyme reactions in amino acid, glucose, and lipid metabolism.

Plants synthesize pyridoxine as a means of protection from the UV-B radiation found in sunlight and for the role it plays in the synthesis of chlorophyll. Animals cannot synthesize any of the various forms of the vitamin, and hence must obtain it via diet, either of plants, or of other animals. There is some absorption of the vitamin produced by intestinal bacteria, but this is not sufficient to meet dietary needs. For adult humans, recommendations from various countries' food regulatory agencies are in the range of 1.0 to 2.0 milligrams (mg) per day. These same agencies also recognize ill effects from intakes that are too high, and so set safe upper limits, ranging from as low as 12 mg/day to as high as 100 mg/day depending on the country. Beef, pork, fowl and fish are generally good sources; dairy, eggs, mollusks and crustaceans also contain vitamin B₆, but at lower levels. There is enough in a wide variety of plant foods so that a vegetarian or vegan diet does not put consumers at risk for deficiency.