With the exception of vitamin B12which is supplied by only foods of animal origin, the water-soluble vitamins are synthesized by plants and found in both plant and animal foods. However, the fact that these vitamins can be stored increases the possibility of toxicity if very large doses are taken.
Minerals have diverse functions, including muscle contraction, nerve transmission, blood clotting, immunity, the maintenance of blood pressure, and growth and development. Unlike the macronutrients, vitamins do not serve as an energy source for the body or provide raw materials for tissue building.
Fluoride is considered a beneficial nutrient because of its role in protecting against Mass media and adolescence how mass cariesalthough an essential function in the strict sense has not been established in human nutrition.
Minerals not only impart hardness to bones and teeth but also function broadly in metabolism—e. Vitamins in food have a distinct advantage over vitamins in supplement form because they come associated with other substances that may be beneficialand there is also less potential for toxicity.
Vitamin nomenclature is somewhat complex, with chemical names gradually replacing the original letter designations created in the era of vitamin discovery during the first half of the 20th century. This recommendation, based on nitrogen balance studies, assumes an adequate energy intake.
As nutrients, minerals are traditionally divided into two groups according to the amounts present in and needed by the body. Although choline may be necessary in the diet of premature infants and possibly of those with certain medical conditions, it has not been established as essential in the human diet throughout life.
The nine water-soluble vitamins soluble in polar solvents are vitamin C and the eight B-complex vitamins: Some vitamins are found in foods in precursor forms that must be activated in the body before they can properly fulfill their function.
When a vitamin is in short supply or is not able to be utilized properly, a specific deficiency syndrome results. Humans are able to synthesize certain vitamins to some extent.
However, consumption of vitamins or other dietary supplements in amounts significantly in excess of recommended levels is not advised without medical supervision. Despite demonstrated roles in experimental animals, the exact function of these and other ultratrace elements e.
The major minerals, with the exception of sulfur, typically occur in the body in ionic charged form: Nutritional supplements cannot substitute for a healthful diet. This is particularly of concern with vitamins A and D, which can be toxic if taken in excess. Water-soluble vitamins are not appreciably stored in the body except for vitamin B12 and thus must be consumed regularly in the diet.
Minerals constitute about 4 to 6 percent of body weight—about one-half as calcium and one-quarter as phosphorus phosphatesthe remainder being made up of the other essential minerals that must be derived from the diet.
Although now known to behave as a hormone, the activated form of vitamin D, vitamin D hormone calcitriolis still grouped with the vitamins as well. However, in general, humans depend on their diet to supply vitamins.
Choline is a vitamin-like dietary component that is clearly required for normal metabolism but that can be synthesized by the body. The term ultratrace elements is sometimes used to describe minerals that are found in the diet in extremely small quantities micrograms each day and are present in human tissue as well; these include arsenicboronnickelsiliconand vanadium.
The major minerals macrominerals —those required in amounts of milligrams or more per day—are calcium, phosphorus phosphatesmagnesiumsulfur, sodiumchlorideand potassium. Strict vegetarians veganswho eat no foods of animal origin, are therefore at risk of vitamin B12 deficiency. For example, vitamin D is produced when the skin is exposed to sunlight ; niacin can be synthesized from the amino acid tryptophan; and vitamin K and biotin are synthesized by bacteria living in the gut.
The B vitamins function as coenzymes that assist in energy metabolism; folic acid folateone of the B vitamins, helps protect against birth defects in the early stages of pregnancy.
Infants, children, and pregnant and lactating women have additional protein needs to support synthesis of new tissue or milk production. Vitamin Eanother antioxidant, protects against free radical damage in lipid systems, and vitamin K plays a key role in blood clotting.
Now considered to be a hormonevitamin D is involved in calcium and phosphorus homeostasis and bone metabolism. However, various forms of a vitamin are not necessarily equivalent. If taken in excess they are readily excreted in the urine, although there is potential toxicity even with water-soluble vitamins; especially noteworthy in this regard is vitamin B6.
Rather, they assist in energy-yielding reactions and facilitate metabolic and physiologic processes throughout the body.
Vitamin Afor example, is required for embryonic development, growth, reproduction, proper immune function, and the integrity of epithelial cells, in addition to its role in vision.
In general, water-soluble vitamins are more easily destroyed during cooking than are fat-soluble vitamins. Vitamin C plays a role in building connective tissue as well as being an antioxidant that helps protect against damage by reactive molecules free radicals.
The 13 vitamins known to be required by human beings are categorized into two groups according to their solubility.Mass media are another important dimension of young peoples’ lives that may take on special signiﬁcance during adolescence, and particularly for sexual risk behavior.
Mass media has long been thought to have a detrimental effect on an adolescent’s values and behaviors. Many social ills including violence, misogyny and negative health behaviors, as well as egoistic cultural values have been attributed to mass media’s influence.
Yet the media is not all powerful, nor are its powers unable to be combated. Essay on How Mass Media Affects the Image of Adolescence - Since the “invention of adolescence”(Clarke ) at the start of the 19th century, we have seen multiple images created in regards to youth, created both politically academically and in the mass media.
The term mass media refers to the channels of communication (media) that exists to reach a large public audience. Mass media includes newspapers, magazines, television, radio, and more recently, the Internet.
Founded inRochester Institute of Technology is a privately endowed, coeducational university with nine colleges emphasizing career education and. Mass media plays a paramount role in today’s society, as it showers over increasing numbers of people all around the world.
Education Index Mass Media and Adolescence: How Mass Media Influence Teens in Their Sexual Behavior. Mass Media and Adolescence: How Mass Media Influence Teens in Their Sexual Behavior “A .Download