nutrition exam 3 - vitamins

Vitamin supplements

..., taken under a primary care provider's guidance, are part of the treatment for preventing a vitamin deficiency associated with fat malabsorption.

coenzyme, small intestine, bioavailability

After being ingested, the B vitamins from food are first broken down from their active ... forms into free vitamins in the stomach and small intestine. The vitamins are then absorbed, primarily in the .... Typically, about 50% to 90% of the water-soluble vitamins in the diet are absorbed, which means they have relatively high ....

vitamin A

Although a toxic effect from an excessive intake of any vitamin is theoretically possible, toxicity of the fat-soluble ... is the most frequently observed.

provitamin A

Although hundreds carotenoids have been identified, just three can be converted to retinol in the body: alpha carotene, beta-carotene, and beta-cryptoxanthin. Because these carotenoids can be turned into vitamin A, they are termed .... Of these three, only beta-carotene serves as a significant source of vitamin A

Coenzyme in many biological reduction and oxidation reactions required for energy metabolism; Meat, fish, poultry, Enriched and whole grains, Fortified ready-to-eat cereals; Pellagra: Diarrhea, Dermatitis, Dementia, Death; Flushing and itchy skin, GI distress

Niacin Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

riboflavin

Symptoms associated with ... deficiency (ariboflavinosis) include inflammation of the mouth and tongue, dermatitis, cracking of tissue around the corners of the mouth Page 309(called cheilosis), various eye disorders, sensitivity to the sun, and confusion

liver, adipose

Unlike other fat-soluble vitamins, vitamin E is not as readily stored in the .... It is stored in ... tissue throughout the body.

Cruciferous

... vegetables are cool-weather vegetables with flowers that have four petals that resemble a cross. The most common of these include broccoli, cauliflower, cabbage, bok choy, Brussels sprouts, and green leafy vegetables such as kale and arugula. Ounce for ounce, they have it all—vitamins, minerals, fiber, and an abundance of disease-fighting phytochemicals.

Preformed

... vitamin A (e.g., retinol, retinal, and retinoic acid) is found in liver, fish, fish oils, fortified milk, butter, yogurt, and eggs. Margarine and spreads are also fortified with vitamin A.

Tobacco, antioxidant

... users need to add an extra 35 milligrams per day to the RDA. The toxic by-products of cigarette smoke and the oxidizing agents found in tobacco products increase the need for the ... action of vitamin C.

vitamin D

... is the only nutrient that is also a hormone.

Carotenoids, five, whole foods

... may play a role in preventing cardiovascular disease in persons at high risk. This may be linked to carotenoids' ability to inhibit the oxidation of low-density lipoproteins (LDLs). Until definitive studies are complete, many scientists recommend that we consume a total of at least ... servings of a combination of fruits and vegetables per day as part of an overall effort to reduce the risk of cardiovascular disease. Other phytochemicals, including flavonoids, phenolic acids, and phytoestrogens, may have a more significant effect in cardiovascular disease prevention than carotenoids. Until we have more answers, focus on consuming a diet rich in phytochemicals from ....

vitamin K, bacteria

A family of compounds known collectively as ... is found in plants, plant oils, fish oils, and animal products. This vitamin is also synthesized by ... in the human colon, which normally fulfills approximately 10% of human requirements.

DNA, homocysteine, neurotransmitters

A key role of the folate coenzyme is to supply or accept single carbon compounds. In this role, folate coenzymes help form ... and metabolize amino acids and their derivatives, such as homocysteine. Folate works along with vitamins B-6 and B-12 to metabolize .... Folate also functions in the formation of ... in the brain. Meeting folate needs can improve the depressed state in some cases of mental illness.

choline , lipoproteins, lipid transport proteins

As part of phospholipids, ... is a component of ..., which carry lipids through the blood. Choline deficiencies in animals and humans lead to decreased production of..., such as very low density lipoproteins (VLDL). The inability of the liver to export fat to the rest of the body leads to the buildup of fat in the liver.

enzymes

As part of the freezing process, vegetables are quickly blanched in boiling water. Blanching destroys the ... that would otherwise degrade the vitamins over time.

metabolically, replaced

B vitamin-deficiency symptoms typically occur in the brain and nervous system, skin, and gastrointestinal (GI) tract. Cells in these tissues are ... active, and those in the skin and GI tract are also constantly being ....

cardiovascular, immune, nervous

Because of the role of vitamin B-6 in hemoglobin synthesis, a deficiency in vitamin B-6 would affect multiple body systems, including the ..., ..., and ... systems, as well as overall energy metabolism. Vitamin B-6 deficiency also results in widespread symptoms, including depression, vomiting, skin disorders, irritation of the nerves, anemia, and impaired immune response.

plants, germ

Because vitamin E is only synthesized by ..., these products (especially the oils) are the best sources. In the North American diet, nearly two-thirds of vitamin E is supplied by salad oils, margarines, spreads (low-fat margarine), and shortening (Fig. 8-13). Breakfast cereals fortified with vitamin E are good sources, but other than wheat germ, few other grain products provide much vitamin E. Milling of grains removes the ..., which contains the oils (mostly PUFAs) and vitamin E. By removing this, the resulting grain product has less chance of spoiling (i.e., rancidity of the PUFAs) and thus a longer shelf life. Other good sources of vitamin E are nuts and seeds.

osteocalcin

Besides its role in blood clotting, vitamin K is also important for bone health. Three calcium-binding proteins (e.g., ...) in the bone depend upon vitamin K for their function in bone mineralization.

tryptophan

Besides the preformed niacin found in foods, we can synthesize niacin from the amino acid .... In this manner, we synthesize about 50% of the niacin required each day. This reaction requires two other vitamins (riboflavin and vitamin B-6) to function as coenzymes in this chemical conversion.

Coenzyme in synthesis of fat, glycogen, and amino acids; Liver, Small amounts in fruits and meats; Dermatitis, Tongue soreness, Anemia, Depression; Unknown

Biotin Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

vitamins

By definition, .... are essential organic (carbon-containing) substances needed in small amounts in the diet for normal function, growth, and maintenance of the body.

oxidative, atherosclerosis

Increasing vitamin E intake has been suggested as a way to prevent several chronic diseases that are linked to ... damage. For example, oxidized LDL cholesterol is a major component of the plaque that develops in arteries, which leads to .... Vitamin E is thought to attenuate the development of atherogenic plaque due to its ability to prevent or reduce the formation of oxidized LDL cholesterol.

betaine, neurotransmitters, homocysteine

Choline is a precursor for ..., a compound that participates in many chemical reactions that involve the transfer of single-carbon groups in metabolism. Important examples of metabolic pathways that involve the transfer of single-carbon groups include the synthesis of ..., modifications of DNA during embryonic development, and the metabolism of ....

phospholipids, flexibility, brain

Choline is a precursor for several .... Phosphatidylcholine (also known as lecithin) accounts for about half of the phospholipids in cell membranes. Recall from Chapter 5 that phospholipids contribute to the ... of cell membranes and allow for the presence of both water- and fat-soluble compounds in cell membranes. With its role in cell membrane structure, choline is important for the health of every cell and particularly for the health of ... tissue, where it is present in high levels.

Fatty fish, Eggs

Dietary sources of vitamin D are limited, with very few foods being naturally high in vitamin D (Fig. 8-11). ... are considered the richest natural sources of vitamin D. Wild-caught salmon tops the list with around 600 to 1000 IU of vitamin D in a 3.5-ounce serving. Farmed salmon contains less at between 100 to 250 IU per 3.5-ounce serving. Tuna is a bit farther down the list with 6 ounces of canned light tuna providing about 300 IU. ... are another natural source with 1 large yolk delivering 41 IU. Although butter, liver, and a few brands of margarine contain some vitamin D, large servings must be eaten to obtain an appreciable amount of the vitamin; therefore, these foods are not considered significant sources.

calcium, metabolic, death

Due to the role of vitamin D in calcium absorption, excretion, and release of calcium from bone, supplementation with high doses of vitamin D can cause ... levels in the blood to increase above the normal range. The UL is based on the risk of overabsorption of calcium and eventual calcium deposits in the kidneys and other organs. Calcium deposits in organs can cause ... disturbances and cell .... Toxicity symptoms also include weakness, loss of appetite, diarrhea, vomiting, mental confusion, and increased urine output.

vitamin D, fat absorption

Individuals who are most at risk of a ... deficiency are older than the age of 60, live in northern latitudes, have dark skin, are rarely outdoors or always wear sunscreen while outdoors, have chronic kidney disease, take medications that interfere with vitamin D absorption, have a condition that prevents ... absorption, or have had part of their stomach or intestine removed.

K, tissue saturation, B-6, B-12

Excretion of vitamins varies primarily on their solubility. Except for vitamin ..., fat-soluble vitamins are not readily excreted from the body. Hence, toxicity can be an issue. Water-soluble vitamins are excreted based on ...., the degree to which the tissue vitamin stores are full. Tissue storage capacity is limited. As the tissues become saturated, the rate of excretion via the kidney increases sharply, preventing potential toxicity. Unlike other water-soluble vitamins, ... and ... are stored in the liver and not easily excreted in the urine. In light of the limits of tissue saturation for many water-soluble vitamins, these vitamins should be consumed in the diet daily. However, an occasional lapse in the intake of water-soluble vitamins causes no harm.

Coenzyme in nucleic and amino acid metabolism, Red blood cell synthesis; Enriched cereal grains, Dark leafy vegetables, Enriched and whole grains, Fortified ready-to-eat cereals; Megaloblastic anemia, Neural tube birth defects, Diarrhea, Depression, Fatigue; Masks vitamin B-12 deficiency

Folate (folic acid)† Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

heat, oxygen, vitamin C

Folate is susceptible to destruction by ... and .... The ... present in some food sources of folate, such as orange juice, helps to reduce folate destruction, but food processing and preparation destroy 50% to 90% of the folate in food. This underscores the importance of regularly eating fresh fruits and raw or lightly cooked vegetables.

gene expression, cardiovascular

It is now accepted that the biological effects of vitamin D extend far beyond its roles in calcium regulation and bone health. Vitamin D is involved in ... and cell growth; it binds to and subsequently affects cells of the immune system, brain and nervous system, parathyroid gland, pancreas, skin, muscles, and reproductive organs. In fact, vitamin D is considered one of the most potent regulators of cell growth, capable of influencing normal development of some cells (e.g., skin, colon, prostate, and breast), in turn reducing cancer risk in these sites. Besides its role in influencing cancer risk, evidence suggests that vitamin D has a role in the prevention of several other chronic diseases, such as ... disease, diabetes, and hypertension.

green leafy vegetables, bacteria

Major food sources of the phylloquinone form of vitamin K are ...., broccoli, asparagus, and peas (Fig. 8-15). The menaquinone form of vitamin K is found in some meats, eggs, and dairy products, and is the form synthesized by ....

riboflavin, light

Major sources of ... are ready-to-eat breakfast cereals, milk and milk products, enriched grains, meat, and eggs. Vegetables such as asparagus, broccoli, and various greens (e.g., spinach) are also good sources. This is a relatively stable water-soluble vitamin; however, it is destroyed by .... Milk is sold in paper or opaque plastic containers rather than clear glass to protect this vitamin.

thiamin

Major sources of ... include pork products, whole grains (wheat germ), ready-to-eat breakfast cereals, enriched grains and flour, green beans, milk, orange juice, organ meats, peanuts, dried beans, and seeds

animal

Major sources of vitamin B-6 are ... products and fortified ready-to-eat breakfast cereals

A, D, niacin, K, biotin

Notable exceptions to having a strict dietary need for a vitamin are vitamin ..., which we can synthesize from certain pigments in plants; vitamin ..., synthesized in the body if the skin is exposed to adequate sunlight; ..., synthesized from the amino acid tryptophan; and vitamin ... and ..., synthesized to some extent by the bacteria in the intestinal tract.

prevents, reduce

Numerous well-designed, double-blind studies have failed to show that vitamin C ... colds. Nevertheless, vitamin C does appear to ... the duration of symptoms by a day or so and to lessen the severity of the symptoms. The key to success is to start the supplement as soon as symptoms appear. Once the cold has taken hold, it is too late!

E, folic acid

Of note, the natural form of vitamin ... is much more potent than the synthetic form. In contrast, synthetic ...., the form of the vitamin added to ready-to-eat breakfast cereals and flour, is 1.7 times more potent than the natural vitamin form.

scurvy

On long sea voyages before the mid-eighteenth century, half or more of sailing crews died due to ..., the vitamin C-deficiency disease. The symptoms of this disease, which include bleeding gums, tooth loss, bruising, and scaly skin, illustrate the important function of vitamin C in the formation of connective tissue. Without vitamin C, the skin and blood vessels weaken and wounds will not heal.

folate, megaloblast

One major result of a ... deficiency is that in the early phases of red blood cell synthesis, immature cells cannot divide because they cannot form new DNA. The cells grow progressively larger because they can still synthesize enough protein and other cell parts to make new cells. When the time comes for the cells to divide, the amount of DNA is insufficient to form two nuclei. The cells then remain in a large immature form, known as a ...

K

People with fat-malabsorption conditions are especially susceptible to vitamin ... deficiency because body stores of this vitamin are lower than those of the other fat-soluble vitamins.

folic acid, vitamin B-12

The UL for folate only refers to .... This is because folate, the natural form in food, has limited absorption. Large doses of folic acid can hide the signs of ... deficiency and therefore complicate its diagnosis. Specifically, regular consumption of large amounts of folate can prevent the appearance of an early warning sign of vitamin B-12 deficiency: enlarged red blood cell size. For this reason, FDA limits the amount of folic acid in supplements (for nonpregnant adults) to 400 micrograms.

nerve

The UL for vitamin B-6 (see margin) is based on the risk of developing ... damage.

collagen

The best understood function of vitamin C (also known as ascorbic acid or ascorbate) is its role in the synthesis of .... This protein is highly concentrated in connective tissue, bone, teeth, tendons, and blood vessels. The important function of vitamin C in the formation of connective tissue is exemplified in the early symptoms of a deficiency: pinpoint hemorrhages under the skin, bleeding gums, and joint pain.

niacin, pellagra

The distinct group of ... -deficiency symptoms is known as ..., which means rough or painful skin. The symptoms of the disease are dementia, diarrhea, and dermatitis (especially on areas of skin exposed to the sun). Left untreated, death often results.

Vitamin A, T-lymphocytes

The epithelial tissues serve as important barriers to infection. ... also supports the activity of certain immune system cells, specifically, the ...., or T-cells. This vitamin-deficient humans have an increased infection rate, but when they are supplemented with this vitamin, the immune response improves.

Required for normal vision, Gene expression, Growth, development, reproduction, Embryonic development, Immune function, Cancer prevention; Liver, Fortified dairy, Fish, fish oils, Darkly colored fruits and leafy, vegetables, Fortified milk, Eggs; Deficiency: Night blindness, Xerophthalmia, Inadequate growth, Dry skin, Inadequate immune function; Toxicity: Birth defects, Bone pain and fractures, Liver toxicity, Nervous system disorders, Nausea and vomiting

Vitamin A (preformed and provitamin A) Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

Maintain serum calcium and phosphorus concentrations, Bone health, Gene expression and cell growth; Fish liver oils, Flesh of fatty fish, Egg yolk, Fortified dairy, Fortified cereals; deficiency: Rickets in children, Osteomalacia in adults, Delayed growth, Reduced immunity; toxicity: Hypercalcemia, Decreased renal function and hypercalciuria, Kidney failure, Cardiovascular system failure, Calcification of soft tissues

Vitamin D (calciferol) Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

dietary, absorption, metabolism, sun

Vitamin D deficiency can be traced to poor ... intake, poor ... (e.g., fat malabsorption in children with cystic fibrosis), altered ... (e.g., liver or kidney disease), or inadequate ... exposure.

rickets

Vitamin D deficiency can occur at any time, but when it occurs during infancy and early childhood, the resulting disease is known as ....

small intestine, calcium, kidney, minerals

Vitamin D regulates blood calcium in three ways: (1) it influences the absorption of calcium and phosphorus from the ....; (2) it works in combination with PTH and calcitonin, to regulate ... excretion via the ...; and (3) it affects the deposition or withdrawal of ... from the bones

cataracts

carotenoids may also decrease the risk of ... in the eyes. Research studies point toward the actual fruit and vegetables with their high carotenoid content as contributing to reduced risk for eye disorders. Consuming just carotenoids as supplements for this purpose is not recommended.

vitamin C

guinea pigs and humans are two of the few organisms unable to make their own supply of .....

mineral oil

people who use ... as a laxative risk fat-soluble vitamin deficiencies. Fat-soluble vitamins dissolve in this, but the intestine does not absorb this. Hence, the fat-soluble vitamins are eliminated with this in the feces.

Coenzyme in numerous redox reactions; Organ meats, Milk, Bread products and fortified cereals; Inflammation of the mouth and tongue, Eye disorders; Unknown, No UL

riboflavin Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

green leafy vegetables, organ

the richest sources of folate are .... In addition, other vegetables, orange juice, dried beans, and ... meats are excellent sources of folate

acetylcholine, Sphingomyelin

Choline is part of ..., a neurotransmitter associated with attention, learning, memory, muscle control, and many other functions. ..., a choline-containing phospholipid, is part of the myelin sheath that insulates nerve cells. As mentioned, brain tissue is particularly high in choline.

neural tube defects, spina bifida

Maternal folate deficiency (along with a genetic abnormality related to folate metabolism) has been linked to the development of ... in the fetus. These defects include ...

Coenzyme in fatty acid metabolism; Organ meats, Poultry, Beef, Potatoes, Broccoli, Whole grains, Tomato products, Yeast, Egg yolk; No natural deficiency disease or symptoms; Unknown

Pantothenic acid Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

antioxidant, adipose, lipid

The principal function of vitamin E in humans is as an .... Vitamin E is a fat-soluble vitamin found primarily in ... tissue and in the ... bilayers of cell membranes

Coenzyme for amino acid metabolism, Neurotransmitter synthesis, Red blood cell synthesis; Fortified cereals, Organ meats, Fortified soy-based, meat substitutes; Anemia, Convulsions, Nausea, Dermatitis, Depression; Sensory neuropathy

Vitamin B-6† Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

Connective tissue synthesis, Hormone and neurotransmitter synthesis, Antioxidant, immune function, Improves nonheme iron absorption; Citrus fruits, Potatoes, Brussels sprouts, Cauliflower, Broccoli, Spinach, Strawberries; Scurvy, Poor wound, healing, Pinpoint hemorrhages, Bleeding gums, Fatigue, Infections, Bruises; GI disturbances, Kidney stones, Excess iron absorption

Vitamin C (ascorbic acid) Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

40, 90, cystic fibrosis

When fat absorption is efficient, about ...% to ...% of the fat-soluble vitamins are absorbed. Anything that interferes with normal digestion and absorption of fats, however, also interferes with fat-soluble vitamin absorption. For example, people with ...., a disease that often hampers fat absorption, may develop deficiencies of fat-soluble vitamins.

consistent

When taking Coumadin or similar drugs, it is important to keep vitamin K intake ... from day to day.7

intrinsic factor

While food is in the stomach, the stomach cells release a protein-like compound called the .... When the chyme reaches the duodenum, pancreatic enzymes release vitamin B-12 from R-proteins. The free vitamin B-12 then combines with intrinsic factor. The vitamin B-12-intrinsic factor complex travels the length of the small intestine to the ileum, where vitamin B-12 is finally absorbed.

myelin, paralysis

Another vital function of vitamin B-12 is maintaining the ... sheath that insulates neurons. Initial neurological symptoms of vitamin B-12 deficiencies include irregular muscular actions and impaired reflexes. Eventual destruction of the myelin sheath causes ... and, perhaps, even death. In the past, vitamin B-12 deficiencies eventually led to death, mainly due to the destruction of nerves.

Neurotransmitter and phospholipid synthesis; Milk, Liver, Eggs, Peanuts; No natural deficiency; Fishy body odor, Sweating, Hypotension, Hepatotoxicity

Choline† Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

Osteomalacia, vitamin D, calcium

..., which means soft bone, is an adult disease comparable to rickets. It can result from inadequate calcium intake, inefficient calcium absorption in the intestine, or poor conservation of calcium by the kidneys. It occurs most commonly in people with kidney, stomach, gallbladder, or intestinal disease (especially when most of the intestine has been removed) and in people with cirrhosis of the liver. These diseases affect both ... activation and ... absorption, leading to a decrease in bone mineral density.

protein

Foods rich in ..., such as egg yolks, peanuts, and cheese, are good sources of biotin

functional foods, zoochemicals, phytochemicals

Foods that are sources of the chemicals that provide health benefits beyond being essential dietary nutrients are termed .... Oatmeal is an example of a this as it contains soluble fiber that can lower cholesterol levels. Other foods are modified to improve health benefits. For example, some orange juice is fortified with calcium for bone health. Functional foods can be placed into two categories: (1) ..., health-promoting compounds found in animal food; and (2) ..., health-promoting compounds found in plant foods (phyto means "plant" in Greek). Phytochemicals are responsible for the unique colors, flavors, and odors observed in plants. For plants, phytochemicals serve as an environmental protective mechanism to help plants survive the elements (UV exposure, insects, and other predators).

K, deficiencies

However, because vitamin ... is fairly widespread in foods and some can be synthesized by bacteria in the colon, ... of this vitamin rarely occur.

oxidative, gene expression, insulin, cancer, cholesterol

Phytochemical Functions Stimulate the immune system Reduce inflammation Prevent DNA damage and aid in DNA repair Reduce ... damage to cells Regulate intracellular signaling of hormones and ... Activate ... receptors Inhibit the initiation and proliferation of ..., and stimulate spontaneous cell death Alter the absorption, production, and metabolism of ... Mimic or inhibit hormones and enzymes Decrease the formation of blood clots

cancer, DNA, reduce

Research is underway on the link between folate and ... protection. Because folate aids in ... synthesis, adequate folate status is important to maintain DNA integrity, including the control of certain cancer-promoting genes. Meeting the RDA for folate may be one way to ... cancer risk.

peanuts, eggs

Rich sources of pantothenic acid are sunflower seeds, mushrooms, ..., and ...

biotin

Symptoms of ... deficiency include a scaly inflammation of the skin, changes in the tongue and lips, decreased appetite, nausea, vomiting, a form of anemia, depression, muscle pain and weakness, and poor growth.

deficiency, exhausted

Symptoms of a vitamin ... occur only when that vitamin is lacking in the diet and the body stores are essentially .... For example, for an average person, the diet must be devoid of thiamin for 10 to 14 days or lacking in vitamin C for 20 to 40 days before the first symptoms of deficiencies of these vitamins appear.

B vitamins, metabolic

The ... pathways used by carbohydrates, fats, and amino acids all require input from ... .... Because of their role in energy metabolism, needs for many B vitamins increase somewhat as energy expenditure increases.

beriberi, Alcoholics

The thiamin-deficiency disease is called ..., a word that means "I can't, I can't" in the Sri Lankan language of Sinhalese. This disease was described long before thiamin was discovered to be a vitamin in 1910. The symptoms include weakness, loss of appetite, irritability, nervous tingling throughout the body, poor arm and leg coordination, and deep muscle pain in the calves. A person with this disease often develops an enlarged heart and sometimes severe edema. ... are prone to thiamin deficiency and Wernicke-Korsakoff syndrome.

differentiation, lycopene, antioxidant

Vitamin A and carotenoids have potential benefits but also potential dangers where cancer prevention is concerned. It plays a role in cellular ... and embryonic development. Population studies show that regular consumption of foods rich in carotenoids decreases the risk of several types of cancer, including cancers of the lung, skin, oral cavity, and prostate gland. In particular, the dietary carotenoid ... (the red pigment found in tomatoes, watermelon, pink grapefruit, and guava) seems to protect against prostate cancer—one of the most common cancers among North American men. The role of carotenoids in cancer prevention is thought to be a by-product of their ... activity.

blindness

Vitamin A deficiency is the leading cause of ... worldwide.

Antioxidant, Prevents breakdown of vitamin A and unsaturated fatty acids; Vegetable oils, Unprocessed cereal grains, Nuts, Fruits, Vegetables, Fortified cereals; deficiency: Hemolysis of red blood cells, Nerve damage, Anemia; toxicity: Hemorrhagic toxicity

Vitamin E Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

stomach acid

As we age, ... production declines, and our stomachs have a decreased ability to synthesize the intrinsic factor needed for vitamin B-12 absorption.

sterile gut, injection, antibiotics, fat

At birth, a newborn has a ...—an intestinal tract with an insufficient amount of bacteria. Thus, the newborn cannot produce enough vitamin K to allow for effective blood clotting if the infant is injured or needs surgery. Therefore, vitamin K is routinely administered by ... shortly after birth. In adults, deficiencies of vitamin K have occurred when a person takes ... for an extended time. Chronic use destroys the bacteria that normally produce some of the vitamin K that is absorbed and used by the body. Vitamin K deficiency may also occur when ... absorption is limited.

endosperm, thiamin, riboflavin, niacin, folic acid

In milling grains to make refined products, seeds are crushed and the germ, bran, and husk layers are discarded, leaving just the starch-containing ... in the refined grains. To counteract these losses, in the United States, bread and cereal products made from milled grains are enriched with four B vitamins (..., ..., ..., and ...) and with the mineral iron.

vegetarian

Infants breastfed by ... mothers are at risk for vitamin B-12 deficiency accompanied by anemia and long-term nervous system problems, such as diminished brain growth, degeneration of the spinal cord, and poor intellectual development.

freezing

If produce will not be eaten within a few days of harvest, ... is the best preservation method to retain nutrients.

xerophthalmia, Bitot's spots

If vitamin A deficiency progresses, the cells that line the cornea of the eye (the clear window of the eye) lose the ability to produce mucus. The eye then becomes dry. This disease is called ..., which means dry eye. Eventually, dirt particles scratch the dry surface of the eye, leading to blindness. This can progress to the stage where there is an accumulation of dead cells and secretions on the surface of the eye. This condition is called ...

megadoses, niacin

In addition to their use in correcting deficiency diseases, a few vitamins have also proved useful in treating several nondeficiency diseases. These medical applications require administration of ...., amounts well above typical human needs for the vitamins. For example, (same thing) of a form of ... are used as part of blood cholesterol-lowering treatment for those in need

poultry, fish, beef

Major sources of niacin are tuna, ..., peanuts, ..., ready-to-eat cereals, ..., and asparagus. Coffee and tea also contribute some niacin to the diet. Niacin is heat stable, thus little is lost in cooking.

malabsorption, atrophy, bacterial

Pernicious anemia, which affects about 2% of older adults, is the most common cause of vitamin B-12 .... Other causes are age-related ... of the acid-producing cells of the stomach and ... overgrowth in the small intestine. When acid production is low, bacteria normally present in the large intestine may colonize the small intestine and compete with our intestinal cells for vitamin B-12 absorption. Certain medications also impair vitamin B-12 absorption

Dark, UVB rays

Our ability to absorb UVB rays and synthesize vitamin D is affected by many factors. ... skin pigmentation, geographic latitude, time of day, season of the year, weather conditions, and amount of body surface covered with clothing or sunscreen affect the skin's exposure to ... and therefore vitamin D synthesis.

pernicious anemia

People with ... usually do not lack vitamin B-12 in their diets. Instead, they suffer from an autoimmune disease that destroys the stomach cells that produce gastric acid and intrinsic factor.

provitamin

The ... A carotenoids are mainly found in dark green and yellow-orange vegetables and some fruits. Carrots, spinach and other leafy greens, winter squash, sweet potatoes, broccoli, mangoes, cantaloupe, peaches, and apricots are examples of such sources.

night blindness

The link between vitamin A and night vision has been known since ancient Egyptians used juice extracted from liver to cure ..... Vitamin A performs important functions in light-dark vision and, to a lesser extent, color vision.

calcium, phosphorus

The main function of vitamin D (calcitriol) is to maintain the normal range of ... and ... in the blood.

folate

The most important function is folate metabolism. Vitamin B-12 is required to convert ... coenzymes into the active forms needed for metabolic reactions, such as DNA synthesis. Without vitamin B-12, reactions that require certain active forms of folate do not take place in the cell.

thiamin, C, folate, Heat, light, air

The water-soluble vitamins, particularly ..., vitamin .., and ..., can be destroyed with improper storage and excessive cooking. ..., ..., exposure to the ..., cooking in water, and alkalinity are factors that can destroy vitamins.

phytochemicals

There are no specific dietary recommendations for the amount of ... that should be consumed, except that they should be consumed as food. At present, we know that these have protective functions with minimal side effects when consumed naturally in a variety of foods.

Coenzyme in metabolism of carbohydrates and branched-chain amino acid; Enriched, fortified, or whole grains, Ready-to-eat cereals, Pork; Beriberi resulting in nervous system dysfunction; Unknown, No UL

Thiamin Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

iron, Iron deficiency anemia

Vitamin C enhances ... absorption by keeping it in its most absorbable form, especially as the mineral travels through the alkaline environment of the small intestine. Consuming 75 milligrams or more of vitamin C at a meal significantly increases absorption of the iron consumed at that meal. Increasing intake of vitamin C-rich foods is beneficial for those with poor iron status or for those who choose to limit iron-rich food sources. ... is common in the United States and is the number-one nutritional deficiency worldwide.

preformed vitamin A, animal

Vitamin A is in a group of compounds known as retinoids. There are three active forms of vitamin A: retinol, retinal, and retinoic acid. These are often called ..... They exist only in ... products.

epithelial, mucous, blindness

Vitamin A maintains the health of ... cells, which line internal and external surfaces of the lungs, intestines, stomach, vagina, urinary tract, and bladder, as well as those of the eyes and skin. Retinoic acid is required for immature epithelial cells to develop into mature, functional epithelial cells. Without vitamin A, ...-forming cells, such as those in the intestines and lungs, deteriorate and lose function. For the eye, this can lead to .... Hyperkeratosis, also a result of vitamin A deficiency, is a condition in which skin cells produce too much keratin, blocking the hair follicles and causing gooseflesh or toadskin appearance. The excessive keratin in these skin cells causes the skin to be hard and dry.

proteins, tissues, organs, reproduction

Vitamin A participates in the processes of growth, development, and reproduction in several ways. At the genetic level, vitamin A binds to receptors on DNA to increase synthesis of a variety of .... Some of these are required for growth. During early fetal growth, vitamin A functions in the differentiation and maturation of cells, which ultimately form ... and .... Vitamin A-deficient children experience stunted growth. For bones to grow and elongate, old bone must be remodeled (broken down) so that new bone can be formed. Vitamin A assists with breakdown and formation of healthy bone tissue. Adequate intake of vitamin A is also needed for ...; it aids in sperm production (associated with its epithelial role) and in a normal reproductive cycle for women.

liver

Vitamin A was the first fat-soluble vitamin to be recognized as an important component of food essential for human health. Almost all (90%) of vitamin A is stored in the ...; the remaining 10% is in adipose tissue, kidneys, and the lungs. Either a deficiency or toxicity can cause severe problems, and there is a narrow range of optimal intakes between these two states

mineral, liver, animal

Vitamin B-12 is quite unique among the water-soluble vitamins. It is the only vitamin that contains a ... as part of its structure. Its structure is the largest of all the vitamins. Unlike most water-soluble vitamins, B-12 can be stored to a significant extent in the ..., so it takes many months on a diet devoid of vitamin B-12 for a deficiency to surface. Vitamin B-12 is only naturally found in foods of ... origin.

Coenzyme in nucleic acid metabolism, Red blood cell synthesis; Older adults and vegans may need fortified foods or supplements, Fortified cereals, Meat, Fish, Poultry; Megaloblastic anemia, Nerve damage, Fatigue; Unknown

Vitamin B-12† Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

homocysteine, neurotransmitters, niacin, hemoglobin

Vitamin B-6 also plays a role in ... metabolism. Among the other important functions of vitamin B-6 are synthesis of ... such as serotonin and gamma aminobutyric acid; conversion of tryptophan to ...; breakdown of stored glycogen to glucose; and synthesis of white blood cells and the heme portion of ....

antioxidant, vitamin E

Vitamin C also has a more general function as an ... because it can readily accept and donate electrons. These antioxidant properties have been postulated to reduce the formation of cancer-causing nitrosamines in the stomach. Vitamin C also aids in the reactivation of ... after it has donated an electron to a free radical.

Coenzyme during the synthesis of proteins involved in blood clotting and bone metabolism; Green leafy vegetables, Liver, Plant oils and margarine; deficiency: Hemorrhage, Fractures; toxicity: Disruption of anticlotting medications

Vitamin K Functions? Found in what foods? Deficiency symptoms? Toxicity symptoms?

phylloquinone, menaquinone, menadione

Vitamin K has three forms: (1) ..., the most abundant form of vitamin K, synthesized by green plants; (2) ..., synthesized by gut bacteria; and (3) ..., the synthetic form found in supplements.

calcium, blood clotting

Vitamin K serves as a cofactor in chemical reactions that add CO2 molecules to various proteins, thus enabling these proteins to bind .... This is the biochemical basis for vitamin K's role in the life-and-death process of .... In the clotting cascade (Fig. 8-14), vitamin K imparts calcium-binding ability to seven different proteins, eventually leading to the conversion of soluble fibrinogen into insoluble fibrin (i.e., the clot). The "K" stands for koagulation in the language spoken by the Danish researchers who first noted the relationship between vitamin K and blood clotting.

essential

Vitamins are ... in human diets because they cannot be synthesized in the human body or produced in sufficient amounts

fat, water, Choline

Vitamins can be divided into two broad classes based on solubility: vitamins A, D, E, and K are ...-soluble vitamins, whereas the B vitamins and vitamin C are ...-soluble vitamins. The B vitamins include thiamin, riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, folate, and vitamin B-12. .... is a vitamin-like nutrient but is not technically classified as a vitamin.