chapter 10 nutrition

fat soluble vitamin

A, D, E, and K. fat-soluble vitamins require transport proteins fat-soluble vitamins are held in fatty tissues and the liver until needed fat-soluble vitamins tend to remain in fat-storage sites in the body rather than being excreted, and so are more likely to reach toxic levels when consumed in excess.

choline recommendation

AI Men: 550 mg/day Women: 425 mg/day UL Adults: 3500 mg/day Deficiency Symptoms Liver damage Toxicity Symptoms Body odor, sweating, salivation, reduced growth rate, low blood pressure, liver damage Significant Sources Milk, liver, eggs, peanuts

water souble vitamin

B vitamins (thiamin, riboflavin, niacin, biotin, pantothenic acid, vitamin , folate, and vitamin ) and vitamin C the water-soluble vitamins move directly into the blood water-soluble vitamins freely circulate in the water-filled

niacin symptom

Deficiency Disease Pellagra Deficiency Symptoms Diarrhea, abdominal pain, vomiting; inflamed, swollen, smooth, bright red tongue;Footnote depression, apathy, fatigue, loss of memory, headache; bilateral symmetrical rash on areas exposed to sunlight Toxicity Symptoms Painful flush, hives, and rash ("niacin flush"); nausea and vomiting; liver damage; impaired glucose tolerance

Vitamin B12 Deficiency and Toxicity

Deficiency Symptoms Anemia (large-cell type);Footnote fatigue, degeneration of peripheral nerves progressing to paralysis; sore tongue, loss of appetite, constipation Deficiency Disease Pernicious anemia

Folate Deficiency

Folate deficiency impairs cell division and protein synthesis in a folate deficiency, the replacement of red blood cells and GI tract cells falters two of the first symptoms of a folate deficiency are anemia (ah-NEE-me-ah): and GI tract deterioration the anemia of folate deficiency is known as macrocytic or megaloblastic anemia and is characterized by large, immature red blood cells (see Figure 10-12). Without folate, DNA damage destroys many of the red blood cells as they attempt to divide and mature. The result is fewer, but larger, red blood cells that cannot carry oxygen or travel through the capillaries as efficiently as normal red blood cells. Since the implementation of folate fortification in the United States, the prevalence of macrocytic anemia has decreased dramatically

Niacin Toxicity

Large doses of nicotinic acid can effectively lower LDL cholesterol and triglycerides and raise HDL cholesterol the toxic effects of niacin: liver disease, diabetes, peptic ulcers, gout, irregular heartbeats, inflammatory bowel disease, migraine headaches, and alcoholism. The nicotinamide form does not improve blood cholesterol levels

vitamin in food with heat

Prolonged heating may destroy much of the thiamin in food. Because riboflavin can be destroyed by the ultraviolet rays of the sun or by fluorescent light, foods stored in transparent glass containers are most likely to lose riboflavin. Oxygen destroys vitamin C, so losses occur when foods are cut, processed, and stored; these losses may be enough to reduce its action in the body

Folate Recommendations

RDA Adults: 400μg ULFootnote Adults: 1000μ all women of childbearing age who are capable of becoming pregnant should consume 0.4 milligram (400 micrograms) of folate daily—easily accomplished by eating folate-rich foods, folate-fortified foods, or a multivitamin supplement daily Deficiency Symptoms Anemia (large-cell type);Footnote smooth, red tongue; Footnote mental confusion, weakness, fatigue, irritability, headache; shortness of breath; elevated homocysteine Significant Sources Fortified grains, leafy green vegetables, legumes, seeds, liver Easily destroyed by heat and oxygen

riboflavin rda

RDA Men: 1.3 mg/day Women: 1.1 mg/day Significant Sources Milk products (yogurt, cheese); whole-grain, fortified, or enriched grain products; liver deficient in effect Sore throat; cracks and redness at corners of mouth;Footnote painful, smooth, purplish red tongue;Footnote inflammation characterized by skin lesions covered with greasy scales

niacin rda

RDA Men: 16 mg NE/day Women: 14 mg NE/day ULFootnote Adults: 35 mg/day Chief Functions in the Body Part of coenzymes NAD (nicotinamide adenine dinucleotide) and NADP (its phosphate form) used in energy metabolism Significant Sources Milk, eggs, meat, poultry, fish; whole-grain, fortified, and enriched grain products; nuts and all protein-containing foods

vitamin structure/function/content

Structure. Vitamins are individual units; they are not linked together (as are molecules of glucose or amino acids). Appendix C presents the chemical structure for each of the vitamins. Function. Vitamins do not yield energy when metabolized; many of them do, however, assist the enzymes that participate in the release of energy from carbohydrates, fats, and proteins. Food contents. The amounts of vitamins people ingest from foods and the amounts they require daily are measured in micrograms μ or milligrams (mg), rather than grams

Vitamin B12 Recommendations

The RDA for adults is only 2.4 micrograms of vitamin a day—just over two-millionths of a gram. vitamin b12 is unique among the vitamins in being found almost exclusively in foods derived from animals. Its bioavailability is greatest from milk and fish Microwave heating inactivates vitamin B12 Significant Sources Foods of animal origin (meat, fish, poultry, shellfish, milk, cheese, eggs), fortified cereals fast grown on a vitamin -enriched medium and mixed with that medium provides some vitamin , but yeast itself does not contain active vitamin . Similarly, neither fermented soy products such as miso (a soybean paste) nor sea algae such as spirulina provide active vitamin .

the liver and folate

The liver incorporates excess folate into bile that is then sent to the gallbladder and GI tract. Thus folate travels in the same enterohepatic circulation as bile (

Vitamin B6 Toxicity

The report described neurological damage in people who had been taking more than 2 grams of vitamin daily (20 times the current UL of 100 milligrams per day) for 2 months or more. Toxicity Symptoms Depression, fatigue, irritability, headaches, nerve damage causing numbness and muscle weakness leading to an inability to walk and convulsions; skin lesions

Folate Toxicity

The small percentage of adults who also take high-dose folate supplements, however, can reach levels that are high enough to obscure a vitamin deficiency and delay diagnosis of neurological damage. cause by lack of B12

to estimate niacin equivalents from the tryptophan in dietary protein

To determine the amount of tryptophan in protein, divide grams of protein by 100. Multiply by 1000 to convert grams of tryptophan to milligrams. Because it takes 60 milligrams of tryptophan to make 1 milligram of niacin, divide milligrams of tryptophan by 60 to get niacin equivalents. Add the amount of preformed niacin obtained in the diet.

milk and heat

Ultraviolet light and irradiation destroy riboflavin. For these reasons, milk is sold in cardboard or opaque plastic containers, instead of clear glass bottles

PABA

a component of folate's chemical structure

Vitamin B6

a family of compounds—pyridoxal, pyridoxine, and pyridoxamine. The primary active coenzyme form is PLP (pyridoxal phosphate). which is active in more than 100 reactions, including carbohydrate, fatty acid, and amino acid metabolism PLP valuable in protein and urea metabolism PLP participates in the synthesis of heme (the nonprotein portion of hemoglobin), nucleic acids (such as DNA and RNA), and lecithin (a phospholipid Part of coenzymes PLP (pyridoxal phosphate) and PMP (pyridoxamine phosphate) used in amino acid and fatty acid metabolism; helps to convert tryptophan to niacin and to serotonin; helps to make red blood cells

isoniazid

a medication that inhibits the growth of the tuberculosis bacterium This drug has saved countless lives, but because isoniazid binds and inactivates vitamin , it can induce a deficiency. Whenever isoniazid is used to treat tuberculosis, vitamin supplements must be given to protect against deficiency. Oral contraceptives also seem to decrease the body's vitamin reserves.

inositol

a nonessential nutrient that can be made in the body from glucose. Inositol is a part of cell membrane structures.

carnitine

a nonessential, nonprotein amino acid made in the body from lysine that helps transport fatty acids across the mitochondrial membrane.

Pantothenic Acid

acid: a B vitamin. The principal active form is part of coenzyme A it is involved in more than 100 different steps in the synthesis of lipids, neurotransmitters, steroid hormones, and hemoglobin

Vitamin b6

assists enzymes that metabolize amino acids

pernicious anemia

blood disorder that reflects a vitamin deficiency caused by lack of intrinsic factor and characterized by abnormally large and immature red blood cells. Other symptoms include muscle weakness and irreversible neurological damage.

atrophic gastritis

chronic inflammation of the stomach accompanied by a diminished size and functioning of the mucous membranes and glands. This condition is also characterized by inadequate hydrochloric acid and intrinsic factor—two substances needed for vitamin B12 absorption. •

coenzymes

complex organic molecules that work with enzymes to facilitate the enzymes' activity ex thiamin, riboflavin, niacin, pantothenic acid, and biotin Without its coenzyme, an enzyme cannot function

Wet beriberi

damage to the cardiovascular system and is characterized by dilated blood vessels, which cause the heart to work harder and the kidneys to retain salt and water, resulting in edema Physical examination confirms that this person has wet beriberi. Notice how the impression of the physician's thumb remains on the leg.

GI tract and folate

folate is actively secreted back into the GI tract with bile, it can be reabsorbed repeatedly. If the GI tract cells are damaged, then folate is lost. Such is the case in alcohol abuse; folate deficiency rapidly develops and, ironically, further damages the GI tract. Remember, folate is active in cell multiplication—and the cells lining the GI tract are among the most rapidly replaced cells in the body. When unable to make new cells, the GI tract deteriorates and not only loses folate, but fails to absorb other nutrients as well.

Folate and Heart Disease

folate's key roles in the body is to break down the amino acid homocysteine. Without folate, homocysteine accumulates, which seems to enhance formation of blood clots and atherosclerotic lesions.

vitamin B6 RDA

he RDA for vitamin is based on the amounts needed to maintain adequate levels of its coenzymes. Unlike other water-soluble vitamins, vitamin is stored extensively in muscle tissue RDA Adults (19-50 yr): 1.3 mg/day UL Adults: 100 mg/day Significant Sources Meats, fish, poultry, potatoes and other starchy vegetables, legumes, noncitrus fruits, fortified cereals, liver, soy products Easily destroyed by heat

kidney with the water soluble vitamin

he kidneys, monitoring the blood that flows through them, detect and remove small excesses of water-soluble vitamins; large excesses, however, may overwhelm the system, creating adverse effects

Folate and vitamin

help cells to multiply

Aspirin and antacid

interfere with the body's folate status: aspirin inhibits the action of folate-requiring enzymes, and antacids limit the absorption of folate people who rely heavily on aspirin or antacids should be aware of the nutrition consequences

niacin and tryptophan

is use of tryptophan occurs only after protein synthesis needs have been met. Approximately 60 milligrams of dietary tryptophan is needed to make 1 milligram of niacin A food containing 1 milligram of niacin and 60 milligrams of tryptophan provides the equivalent of 2 milligrams of niacin, or 2 niacin equivalents

alcohol affect thiamin

lcohol impairs thiamin absorption and enhances thiamin excretion in the urine, doubling the risk of deficiency. An estimated four out of five alcoholics are thiamin deficient, which damages the brain's structure and impairs its function Prolonged thiamin deficiency beriberi the thiamin-deficiency disease characterized by muscle weakness, edema, or both

neural tube defects

malformations of the brain, spinal cord, or both during embryonic development that often result in lifelong disability or death. The two main types of neural tube defects are spina bifida (literally "split spine") and anencephaly ("no brain").

To calucate folate

micro-gram of food folate + ( 1.7 X micro-gram of synthetic folate

vitamins

organic, essential nutrients required in small amounts by the body for health. Vitamins regulate body processes that support growth and maintain life

Choline

the body uses choline to make the neurotransmitter acetylcholine and the phospholipid lecithin. During fetal development, choline supports the structure and function of the brain and spinal cord, by supporting neural tube closure and enhancing learning performance.

neural tube

the embryonic tissue that forms the brain and spinal cord.

Pantothenic Acid Deficiency and Toxicity

ts symptoms involve a general failure of all the body's systems and include fatigue, GI distress, and neurological disturbances

B17

vitamin " (laetrile, an alleged "cancer cure" and not a vitamin or a cure by any stretch of the imagination—in fact, laetrile is a potentially dangerous substance

bioflavonoids

vitamin P or hesperidin

biotin rda

Adults: 30μg/day Chief Functions in the Body Part of a coenzyme used in energy metabolism, fat synthesis, amino acid metabolism, and glycogen synthesis Significant Sources Widespread in foods; liver, egg yolks, soybeans, fish, whole grains; also produced by GI bacteria Deficiency Symptoms Depression, lethargy, hallucinations, numb or tingling sensation in the arms and legs; red, scaly rash around the eyes, nose, and mouth; hair loss

Pantothenic Acid rda

Adults: 5 mg/day Chief Functions in the Body Part of coenzyme A, used in energy metabolism Significant Sources Widespread in foods; chicken, beef, potatoes, oats, tomatoes, liver, egg yolk, broccoli, whole grains Easily destroyed by food processing Deficiency Symptoms Vomiting, nausea, stomach cramps; insomnia, fatigue, depression, irritability, restlessness, apathy; hypoglycemia, increased sensitivity to insulin; numbness, muscle cramps, inability to walk

alcohol and B6

Alcohol contributes to the destruction and loss of vitamin from the body when the body breaks down alcohol, it produces acetaldehyde. If allowed to accumulate, acetaldehyde dislodges the PLP coenzyme from its enzymes; once loose, PLP breaks down and is excreted.

Metabolic Pathways Involving B Vitamins

NAD and NADP: niacin TPP: thiamin CoA: pantothenic acid B12: vitamin B12 FMN and FAD: riboflavin THF: folate PLP: vitamin B6 Biotin

Minimizing Nutrient Losses

To slow the degradation of vitamins, refrigerate (most) fruits and vegetables. To minimize the oxidation of vitamins, store fruits and vegetables that have been cut in airtight wrappers, and store juices that have been opened in closed containers (and refrigerate them). To prevent vitamin losses during washing, rinse fruits and vegetables before cutting (not after). To minimize vitamin losses during cooking, use a microwave oven or steam vegetables in a small amount of water. Add vegetables after water has come to a boil. Use the cooking water in mixed dishes such as casseroles and soups. Avoid high temperatures and long cooking times.

Vitamin B6 Deficiency

Without adequate vitamin , synthesis of key neurotransmitters diminishes, and abnormal compounds produced during tryptophan metabolism accumulate in the brain . Early symptoms of vitamin deficiency include depression and confusion; advanced symptoms include abnormal brain wave patterns and convulsions. Low levels of vitamin are associated with increased risks of some cancers and cardiovascular disease

Vitamin B12

a B vitamin characterized by the presence of cobalt. The active forms of coenzyme are methylcobalamin and deoxyadenosylcobalamin removes a methyl group to activate the folate coenzyme. When folate gives up its methyl group, the vitamin B12 coenzyme becomes activated the synthesis of DNA and RNA vitamin B12 enters the enterohepatic circulation—continuously being secreted into bile and delivered to the intestine, where it is reabsorbed The digestion and absorption of vitamin B12 depends on several steps. In the stomach, hydrochloric acid and the digestive enzyme pepsin release vitamin B12 from the proteins to which it is attached in foods. Then as vitamin passes from the stomach to the small intestine, it binds with a stomach secretion called intrinsic factor. Bound together, intrinsic factor and vitamin B12 travel to the end of the small intestine, where receptors recognize the complex. Importantly, the receptors do not recognize vitamin without intrinsic factor. The vitamin is gradually absorbed into the bloodstream as the intrinsic factor is degraded. Transport of vitamin in the blood depends on specific binding proteins. Part of coenzymes methylcobalamin and deoxyadenosylcobalamin used in new cell synthesis; helps to maintain nerve cells; reforms folate coenzyme; helps to break down some fatty acids and amino acids

Biotin

a B vitamin that functions as a coenzyme in metabolism. plays an important role in metabolism as a coenzyme that carries activated carbon dioxide The biotin coenzyme also participates in gluconeogenesis, fatty acid synthesis, and the breakdown of certain fatty acids and amino acids. Biotin-deficiency symptoms include skin rash, hair loss, and neurological impairment

riboflavin

a B vitamin. The coenzyme forms are FMN (flavin mono nucleotide) and FAD (flavin adenine dinucleotide). both can accept and then donate two hydrogen during the tca cycle the compound release hydrogen and fad pick it up to be come fadh2 and it carries hydrogen to the electron transport and it interact with oxygen to make water and 2 atp is produce lack of the vitamin causes inflammation of the membranes of the mouth, skin, eyes, and GI tract no serious side effect

niacin

a B vitamin. The coenzyme forms are NAD (nicotinamide adenine dinucleotide) and NADP (the phosphate form of NAD). Niacin can be eaten preformed or made in the body from its precursor, tryptophan, an essential amino acid. They are central in energy-transfer reactions, especially the metabolism of glucose, fat, and alcohol NAD is similar to the riboflavin coenzymes in that it carries hydrogens (and their electrons) during metabolic reactions, including the pathway from the TCA cycle to the electron transport chain. NAD also protects against neurological degeneration.

folate

a B vitamin; also known as folic acid, folacin, or pteroylglutamic (tare-o-EEL-glue-TAM-ick) acid (PGA). The coenzyme forms are DHF (dihydrofolate) and THF (tetrahydrofolate). ts primary coenzyme form, THF (tetrahydrofolate), serves as part of an enzyme complex that transfers 1-carbon compounds that arise during metabolism.Footnote This action converts vitamin B12 to one of its coenzyme forms, synthesizes the DNA required for all rapidly growing cells, and regenerates the amino acid methionine from homocysteine it explains that foods deliver folate mostly in the "bound" form—that is, combined with a string of amino acids (all glutamate), known as polyglutamate. (See Appendix C for the chemical structure.) Enzymes on the intestinal cell surfaces hydrolyze the polyglutamate to monoglutamate—folate with only one glutamate attached—and several single glutamates. The monoglutamate is then attached to a methyl group and delivered to the liver and other body cells. To activate folate, the methyl group CH3 must be removed by an enzyme that requires the help of vitamin B12 . Without that help, folate becomes trapped inside cells in its methyl form, unavailable to support DNA synthesis and cell growth.

Dry beriberi

damage to the nervous system and is characterized by muscle weakness in the arms and legs

bioavailability

he rate at and the extent to which a nutrient is absorbed and used in the body depend on Efficiency of digestion and time of transit through the GI tract Previous nutrient intake and nutrition status Method of food preparation (raw, cooked, or processed) Source of the nutrient (synthetic, fortified, or naturally occurring) Other foods consumed at the same time

Niacin Deficiency

pellagra the niacin-deficiency disease, characterized by diarrhea, dermatitis, dementia, and eventually death. In the early 1900s, pellagra caused widespread misery and some 87,000 deaths in the US South, where many people subsisted on a low-protein diet centered on corn. This diet supplied neither enough niacin nor enough tryptophan. At least 70 percent of the niacin in corn is bound to complex carbohydrates and small peptides, making it unavailable for absorption. Furthermore, corn is high in the amino acid leucine, which interferes with the tryptophan-to-niacin conversion, thus further contributing to the development of pellagra.

precursors aka provitamin

substances that precede others; with regard to vitamins, compounds that can be converted into active vitamins

Thiamin (bvit)

the vitamin part of the coenzyme TPP (thiamin pyrophosphate The TPP coenzyme participates in the conversion of pyruvate to acetyl CoA carbohydrate fuel to enter the TCA cycle and produce much more ATP than during glycolysis nerve activity and muscle activity in response to nerves depend heavily on thiamin

vegetarian diet and b12

vitamin is found primarily in foods derived from animals, people who follow a vegetarian diet may develop a vitamin deficiency.It may take several years for people who stop eating animal-derived foods to develop deficiency symptoms because the body recycles much of its vitamin , reabsorbing it over and over again. Even when the body fails to absorb vitamin , deficiency may take up to 3 years to develop because the body conserves its supply. Neurological degeneration, a sign of vitamin deficiency, appears more rapidly in infants born to mothers with unsupplemented vegan diets or untreated pernicious anemia.

recommendation of thiamin

women: 1.1 mg/day Men: 1.2 mg/day Significant Sources whole-grain, fortified, or enriched grain products; moderate amounts in all nutritious food; pork Deficiency SymptomsFootnote Enlarged heart, cardiac failure; muscular weakness; apathy, poor short-term memory, confusion, irritability; anorexia, weight loss