Unit- IX FOOD AND NUTRITION

Unit- IX

FOOD AND NUTRITION

VITAMIN DEFECIENCY

List of vitamins

Each vitamin is typically used in multiple reactions, and, therefore, most have multiple functions.^[18]

Vitamin generic descriptor name	Vitamerchemical name(s) (list not complete)	Solubility	Recommended dietary allowances (male, age 19–70)[19]	Deficiency disease	Upper Intake Level (UL/day)[19]	Overdose disease	Good sources
Vitamin K	phylloquinone ,menaquinones	Fat	120 µg	Bleeding diathesis	N/D	Increases coagulation in patients takingwarfarin.[31]	Leafy green vegetables such as spinach, egg yolks, liver
Vitamin E	Tocopherols,tocotrienols	Fat	15.0 mg	Deficiency is very rare; mildhemolytic anemia in newborn infants.[29]	1,000 mg	Increased congestive heart failure seen in one large randomized study.[30]	Many fruits and vegetables
Vitamin D	Cholecalciferol	Fat	5.0 µg–10 µg[28]	Rickets andOsteomalacia	50 µg	Hypervitaminosis D	Fish, eggs, liver, mushrooms
Vitamin C	Ascorbic acid	Water	90.0 mg	Scurvy	2,000 mg	Vitamin C megadosage	Many fruits and vegetables, liver
Vitamin B9	Folic acid, folinic acid	Water	400 µg	Megaloblast and Deficiency during pregnancy is associated withbirth defects, such as neural tube defects	1,000 µg	May mask symptoms of vitamin B12deficiency; other effects.	Leafy vegetables, pasta, bread, cereal, liver
Vitamin B7	Biotin	Water	30.0 µg	Dermatitis,enteritis	N/D		Raw egg yolk, liver, peanuts, certain vegetables
Vitamin B6	Pyridoxine,pyridoxamine,pyridoxal	Water	1.3–1.7 mg	Anemia[26]peripheral neuropathy.	100 mg	Impairment ofproprioception, nerve damage (doses > 100 mg/day)	Meat, vegetables, tree nuts, bananas
Vitamin B5	Pantothenic acid	Water	5.0 mg[24]	Paresthesia	N/D	Diarrhea; possibly nausea and heartburn.[25]	Meat, broccoli, avocados
Vitamin B3	Niacin,niacinamide	Water	16.0 mg	Pellagra	35.0 mg	Liver damage (doses > 2g/day)[23] andother problems	Meat, fish, eggs, many vegetables, mushrooms, tree nuts
Vitamin B2	Riboflavin	Water	1.3 mg	Ariboflavinosis	N/D		Dairy products, bananas, popcorn, green beans, asparagus
Vitamin B12	Cyanocobalamin,hydroxycobalamin,methylcobalamin	Water	2.4 µg	Megaloblastic anemia[27]	N/D	Acne-like rash [causality is not conclusively established].	Meat and other animal products
Vitamin B1	Thiamine	Water	1.2 mg	Beriberi,Wernicke-Korsakoff syndrome	N/D[21]	Drowsiness or muscle relaxation with large doses.[22]	Pork, oatmeal, brown rice, vegetables, potatoes, liver, eggs
Vitamin A	Retinol, retinal, and four carotenoids including beta carotene	Fat	900 µg	Night-blindness,Hyperkeratosis, andKeratomalacia[20]	3,000 µg	Hypervitaminosis A	Orange, ripe yellow fruits, leafy vegetables, carrots, pumpkin, squash, spinach, liver

[edit]In nutrition and diseases

Vitamins are essential for the normal growth and development of a multicellular organism. Using the genetic blueprint inherited from its parents, a fetus begins to develop, at the moment of conception, from the nutrients it absorbs. It requires certain vitamins and minerals to be present at certain times. These nutrients facilitate the chemical reactions that produce among other things, skin, bone, andmuscle. If there is serious deficiency in one or more of these nutrients, a child may develop a deficiency disease. Even minor deficiencies may cause permanent damage.^[32]

For the most part, vitamins are obtained with food, but a few are obtained by other means. For example, microorganisms in the intestine — commonly known as "gut flora" — produce vitamin K and biotin, while one form of vitamin D is synthesized in the skin with the help of the natural ultraviolet wavelength of sunlight. Humans can produce some vitamins from precursors they consume. Examples include vitamin A, produced from beta carotene, and niacin, from the amino acid tryptophan.^[19]

Once growth and development are completed, vitamins remain essential nutrients for the healthy maintenance of the cells, tissues, and organs that make up a multicellular organism; they also enable a multicellular life form to efficiently use chemical energy provided by food it eats, and to help process the proteins, carbohydrates, and fats required for respiration.^[3]

[edit]Deficiencies

It was suggested that, when plants and animals began to transfer from the sea to rivers and land about 500 million years ago, environmental deficiency of marine mineral antioxidants was a challenge to the evolution of terrestrial life. Terrestrial plants slowly optimized the production of "new" endogenous antioxidants such as ascorbic acid (Vitamin C), polyphenols, flavonoids, tocopherols, etc. Since this age, dietary vitamin deficiencies appeared in terrestrial animals.^[33] Humans must consume vitamins periodically but with differing schedules, to avoid deficiency. The human body's stores for different vitamins vary widely; vitamins A, D, and B₁₂ are stored in significant amounts in the human body, mainly in the liver,^[29] and an adult human's diet may be deficient in vitamins A and D for many months and B₁₂ in some cases for years, before developing a deficiency condition. However, vitamin B₃ (niacin and niacinamide) is not stored in the human body in significant amounts, so stores may last only a couple of weeks.^[20][29] For vitamin C, the first symptoms of scurvy in experimental studies of complete vitamin C deprivation in humans have varied widely, from a month to more than six months, depending on previous dietary history that determined body stores.^[34]

Deficiencies of vitamins are classified as either primary or secondary. A primary deficiency occurs when an organism does not get enough of the vitamin in its food. A secondary deficiency may be due to an underlying disorder that prevents or limits the absorption or use of the vitamin, due to a "lifestyle factor", such as smoking, excessive alcohol consumption, or the use of medications that interfere with the absorption or use of the vitamin.^[29] People who eat a varied diet are unlikely to develop a severe primary vitamin deficiency. In contrast, restrictive diets have the potential to cause prolonged vitamin deficits, which may result in often painful and potentially deadlydiseases.

Well-known human vitamin deficiencies involve thiamine (beriberi), niacin (pellagra), vitamin C (scurvy), and vitamin D (rickets). In much of the developed world, such deficiencies are rare; this is due to (1) an adequate supply of food and (2) the addition of vitamins and minerals to common foods, often called fortification.^[19][29] In addition to these classical vitamin deficiency diseases, some evidence has also suggested links between vitamin deficiency and a number of different disorders.^[35][36]

[edit]Side-effects and overdose

In large doses, some vitamins have documented side-effects that tend to be more severe with a larger dosage. The likelihood of consuming too much of any vitamin from food is remote, but overdosing (vitamin poisoning) from vitamin supplementation does occur. At high enough dosages, some vitamins cause side-effects such as nausea, diarrhea, and vomiting.^[20][37] When side-effects emerge, recovery is often accomplished by reducing the dosage. The doses of vitamins differ because individual tolerances can vary widely and appear to be related to age and state of health.^[38]

In 2008, overdose exposure to all formulations of vitamins and multivitamin-mineral formulations was reported by 68,911 individuals to the American Association of Poison Control Centers (nearly 80% of these exposures were in children under the age of 6), leading to 8 "major" life-threatening outcomes and 0 deaths.^[39]

[edit]Supplements

Dietary supplements, often containing vitamins, are used to ensure that adequate amounts of nutrients are obtained on a daily basis, if optimal amounts of the nutrients cannot be obtained through a varied diet. Scientific evidence supporting the benefits of some vitamin supplements is well established for certain health conditions, but others need further study.^[40] In some cases, vitamin supplements may have unwanted effects, especially if taken before surgery, with other dietary supplements or medicines, or if the person taking them has certain health conditions.^[40] Dietary supplements may also contain levels of vitamins many times higher, and in different forms, than one may ingest through food.^[41]

There have been mixed studies on the importance and safety of dietary supplementation. A meta-analysis published in 2006 suggested that Vitamin A and E supplements not only provide no tangible health benefits for generally healthy individuals but may actually increase mortality, although two large studies included in the analysis involved smokers, for whom it was already known thatbeta-carotene supplements can be harmful.^[42] Another study published in May 2009 found that antioxidants such as vitamins C and E may actually curb some benefits of exercise.^[43] While others findings suggest that evidence of Vitamin E toxicity is limited to specific form taken in excess.^[44] A double-blind trial published in 2011 found that vitamin E increases the risk of prostate cancer in healthy men.^[45]

[edit]Governmental regulation of vitamin supplements

Most countries place dietary supplements in a special category under the general umbrella of foods, not drugs. This necessitates that the manufacturer, and not the government, be responsible for ensuring that its dietary supplement products are safe before they are marketed. Regulation of supplements varies widely by country. In the United States, a dietary supplement is defined under the Dietary Supplement Health and Education Act of 1994.^[46] In addition, the Food and Drug Administration uses the Adverse Event Reporting System to monitor adverse events that occur with supplements.^[47] In the European Union, the Food Supplements Directive requires that only those supplements that have been proven safe can be sold without a prescription.^[48]

[edit]Names in current and previous nomenclatures

Nomenclature of reclassified vitamins
Previous name	Chemical name	Reason for name change[49]
Vitamin B4	Adenine	DNA metabolite; synthesized in body
Vitamin B8	Adenylic acid	DNA metabolite; synthesized in body
Vitamin F	Essential fatty acids	Needed in large quantities (does not fit the definition of a vitamin).
Vitamin G	Riboflavin	Reclassified as Vitamin B2
Vitamin H	Biotin	Reclassified as Vitamin B7
Vitamin J	Catechol, Flavin	Catechol nonessential; flavin reclassified as B2
Vitamin L1[50]	Anthranilic acid	Non essential
Vitamin L2[50]	Adenylthiomethylpentose	RNA metabolite; synthesized in body
Vitamin M	Folic acid	Reclassified as Vitamin B9
Vitamin O	Carnitine	Synthesized in body
Vitamin P	Flavonoids	No longer classified as a vitamin
Vitamin PP	Niacin	Reclassified as Vitamin B3
Vitamin S	Salicylic acid	Proposed inclusion[51] of salicylate as an essential micronutrient
Vitamin U	S-Methylmethionine	Protein metabolite; synthesized in body

The reason that the set of vitamins skips directly from E to K is that the vitamins corresponding to letters F-J were either reclassified over time, discarded as false leads, or renamed because of their relationship to vitamin B, which became a complex of vitamins.

The German-speaking scientists who isolated and described vitamin K (in addition to naming it as such) did so because the vitamin is intimately involved in theKoagulation of blood following wounding. At the time, most (but not all) of the letters from F through to J were already designated, so the use of the letter K was considered quite reasonable.^[49][52] The table on the right lists chemicals that had previously been classified as vitamins, as well as the earlier names of vitamins that later became part of the B-complex.

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UNDER WEIGH

The most common cause of a person being underweight is primarily malnutrition caused by the unavailability of adequate food.

Some people are underweight due to genetics;^[1][2] others due to poverty.

Being underweight can sometimes be the result of mental or physical disease, such as hyperthyroidism, cancer, or tuberculosis. People with gastrointestinal or liver problems may be unable to absorb nutrients adequately. People with eating disorders, such asanorexia nervosa, are likely to become underweight.

[edit]Problems

Underweight might be secondary to or symptomatic of an underlying disease. Unexplained weight loss may require professional medical diagnosis.

Underweight can also be a primary causative condition. Severely underweight individuals may have poor physical stamina and a weakimmune system, leaving them open to infection. According to Robert E. Black of the Johns Hopkins School of Public Health, "Underweight status ... and micronutrient deficiencies also cause decreases in immune and non-immune host defenses, and should be classified as underlying causes of death if followed by infectious diseases that are the terminal associated causes."^[3] People who are malnutrative underweight raise special concerns, as not only gross caloric intake may be inadequate, but also intake and absorption of other vital nutrients, especially essential amino acids and micro-nutrients such as vitamins and minerals.

In women, being grossly underweight can result in amenorrhea (absence of menstruation), infertility and possible complications duringpregnancy. It can also cause anemia and hair loss.

Underweight is an established^[4] risk factor for osteoporosis, even for young people. This is a particular insidious consequence, because the affected persons do not notice the danger.^[5][6] After the occurrence of first spontaneous fractures the damage is often already irreversible.

Being underweight causes increased mortality at rates comparable to that seen in morbidly obese people.^[7]

[edit]Treatment

This section may require copy-editing.

[edit]Diet

Underweight individuals may be advised to gain weight by increasing calorie intake by, for example, eating calorie-dense foods, such as dried fruits, cheese, raisins, and nuts.^[8] Body weight may also be increased through the consumption of liquid nutritional supplements, such as Ensure and Boost.^[9] Other nutritional supplements may be recommended for individuals with insufficient vitamin or mineral intake.^[10][11]

[edit]Exercise

Another way for underweight people to gain weight is by exercising. The addition of muscles will increase your body mass. Weight-lifting exercises are effective in helping to increase muscle tone as well as helping with gaining weight.^[12]

[edit]Appetite stimulants

Main article: Orexigenic

Finally, certain drugs may increase appetite either as their primary effect, or

as a side-effect as in the majority of cases. Antidepressants such as mirtazapine or amitryptiline, antipsychotics (particularly chlorpromazine and haloperidol, as well astetrahydrocannabinol (found in cannabis), all present an increase in appetite as a side-effect. In states where it is approved, medicinal marijuana may be prescribed for severe appetite loss, such as that caused by cancer, AIDS or even severe levels of persistentanxiety. Other drugs which may increase appetite include certain benzodiazepines (such as diazepam), sedating antihistamines (such as diphenhydramine or promethazine, or B vitamin supplements.

Exercise itself is catabolic, which results in a brief reduction in mass. The gain in weight that can result of it comes from the anabolicover-compensation when the body recovers (via rest and eating) and overcompensates via muscle hypertrophy. This can happen via an increase in the muscle proteins, or through enhanced storage of glycogen in muscles. Exercise can help stimulate people's appetite if they are not inclined to eat.