Nutrition 1000 Chapter 8

fat soluble vitamins

A, D, E, K

fat soluble vitamins

Vitamins that dissolve in fat and such substances as ether and benzene but not readily in water. These vitamins are A, D, E, and K.

vitamin A

carrots, good for your eyes

vitamin C and vitamin E play a role in?

immunity

immunity

vitamin A, C, D, E

antioxidant systems

vitamin A, C, E, carotenoids

blood health

vitamin B-6, B-12, folate, vitamin K

do people who use mineral oil as a laxative at mealtimes risk fat-soluble vitamin deficiencies?

yes, fat-soluble vitamins dissolve in the mineral oil, but the intestine does not absorb mineral oil. Hence, the fat-soluble vitamins are eliminated with the mineral oil in the feces.

what happens when you consume more than the RDA or AI for most water soluble vitamins?

the kidneys efficiently filter the excess from the blood and excrete these compounds in urine.

bone health

vitamin C, D, K

What criteria must a compound meet to be classified as a vitamin?

(1) the body is unable to synthesize enough of the compound to maintain health and (2) absence of the compound from the diet for a defined period produces deficiency symptoms that, if caught in time, are quickly cured when the compound is resupplied. A compound does not qualify as a vitamin merely because the body cannot make it. Evidence must suggest that health declines when the substance is not consumed.

describe the characteristics of fat soluble vitamins

- Vitamins that dissolve in fat and such substances as ether and benzene but not readily in water, stored in body tissues. - stay in your body longer

describe the characteristics of water soluble vitamins

- Vitamins that dissolve in water - need to be replaced daily - secreted easily - can be damaged by overcooking veggies

tips for preserving vitamins in fruits and vegetables

1. Keep fruits and vegetables cool until eaten. REASON: Enzymes in fruits and vegetables begin to degrade vitamins once they are harvested. Chilling limits this process. 2. Refrigerate fruits and vegetables (except bananas, onions, potatoes, and tomatoes) in moisture-proof, airtight containers or in the vegetables drawer. REASON: Nutrients keep best at temperatures near freezing, at high humidity, and away from air. 3. Trim, peel, and cut fruits and vegetables minimally—just enough to remove inedible parts. REASON: Oxygen breaks down vitamins faster when more of the food surface is exposed. Whenever possible, cook fruits and vegetables in their skins. 4. Microwave, steam, or stir-fry vegetables. REASON: More nutrients are retained when there is less contact with water and shorter cooking time. 5. Minimize cooking time. REASON: Prolonged cooking (slow simmering) and reheating reduce vitamin content. 6. Avoid adding fats to vegetables during cooking if you plan to discard the liquid. REASON: Fat-soluble vitamins will be lost in discarded fat. If you want to add fats, do so after vegetables are fully cooked and drained. 7. Do not add baking soda to vegetables to enhance the green color. REASON: Alkalinity destroys vitamin D, thiamin, and other vitamins. 8. Store canned and frozen fruits and vegetables carefully. REASON: To protect canned foods, store them in a cool, dry location. To protect frozen foods, store them at 0°F (−32°C) or colder. Eat within 12 months.

coenzyme

A compound (e.g., water-soluble vitamin) that combines with an inactive enzyme to form a catalytically active form. In this manner, coenzymes aid in enzyme function.

rickets

A disease characterized by poor mineralization of newly synthesized bones because of low calcium content. Arising in infants and children, this deficiency is caused by insufficient amounts of the vitamin D hormone in the body.

How much vitamins do humans require?

A total of about 1 ounce (28 grams) of vitamins for every 150 pounds (70 kilograms) of food consumed

water soluble vitamins

B and C

Name the characteristic nutrients for the protein food group

B vitamins, iron, zinc

vitamin

Compound needed in very small amounts in the diet to help regulate and support chemical reactions in the body for normal function, growth, and maintenance of the body. Essential organic (carbon-containing) substances

Are natural vitamins or synthesized vitamins more healthful?

Contrary to claims in the health-food literature, "natural" vitamins isolated from foods are, with few exceptions, no more healthful or effective than those synthesized in a laboratory

community-supported agriculture (CSA)

Farms that are supported by a community of growers and consumers who provide mutual support and share the risks and benefits of food production, usually including a system of weekly delivery or pick up of vegetables and fruit, and sometimes dairy products and meat.

where are fat soluble vitamins stored?

Fat-soluble vitamins are stored mostly in the liver and fatty tissues.

what are steps you can take in order to preserve the nutrients in your foods?

Frozen vegetables and fruits are often as nutrient-rich as freshly picked ones because fruits and vegetables are typically frozen immediately after harvesting. As part of the freezing process, vegetables are quickly blanched in boiling water. Blanching destroys the enzymes that would otherwise degrade the vitamins. If a food is not to be eaten within a few days of harvest, freezing is the best preservation method to retain nutrients.

why should we be wary of our intake of fat soluble vitamins?

In contrast to the water-soluble vitamins, fat-soluble vitamins are not readily excreted, so some can easily accumulate in the body and cause toxic effects

megadose

Intake of a nutrient beyond estimates of needs to prevent a deficiency or what would be found in a balanced diet; 2 to 10 times human needs is a starting point for such a dosage.

Name the characteristic nutrients for the grain food group

The B vitamins thiamin, riboflavin, and niacin play a key role in metabolism - they help the body release energy from protein, fat, and carbohydrates. B vitamins are also essential for a healthy nervous system. Many refined grains are enriched with these B vitamins. Folate (folic acid), another B vitamin, helps the body form red blood cells. Women of childbearing age who may become pregnant should consume adequate folate from foods, and in addition 400 mcg of synthetic folic acid from fortified foods or supplements. This reduces the risk of neural tube defects, spina bifida, and anencephaly during fetal development B vitamins (thiamin, riboflavin, niacin, folic acid, iron, fiber

how are the fat-soluble vitamins (A, D, E, and K) absorbed?

The fat-soluble vitamins (A, D, E, and K) are absorbed along with dietary fat. These vitamins then travel with dietary fats as part of chylomicrons through the bloodstream to reach body cells. Special carriers in the bloodstream help distribute some of these vitamins.

tissue saturation

The limited storage capacity of water-soluble vitamins in the tissues.

scurvy

The vitamin C-deficiency disease characterized by weakness, fatigue, slow wound healing, opening of previously healed wounds, bone pain, fractures, sore and bleeding gums, diarrhea, and pinpoint hemorrhages on the skin.

what causes the rate of excretion via the kidney to increase sharply, preventing potential toxicity.

Tissue storage capacity is limited. As the tissues become saturated the rate of excretion via the kidney increases sharply

Name the characteristic nutrients for the vegetable food group

Vitamin A keeps eyes and skin healthy and helps to protect against infections. Vitamin C helps heal cuts and wounds and keeps teeth and gums healthy. Vitamin C aids in iron absorption. Folate (folic acid) helps the body form red blood cells. Women of childbearing age who may become pregnant should consume adequate folate from foods, and in addition 400 mcg of synthetic folic acid from fortified foods or supplements. This reduces the risk of neural tube defects, spina bifida, and anencephaly during fetal development. Vitamin A and C, folate, fiber

Name the characteristic nutrients for the fruit food group

Vitamin C is important for growth and repair of all body tissues, helps heal cuts and wounds, and keeps teeth and gums healthy. Vitamin C and A, fiber

what is part of the treatment for preventing a vitamin deficiency associated with fat malabsorption?

Vitamin supplements, taken under a physician's guidance

water soluble vitamins

Vitamins that dissolve in water. These vitamins are the B vitamins and vitamin C.

describe the transportation of water soluble vitamins.

Water-soluble vitamins are transported to the liver via the hepatic portal vein and are distributed to body tissues. Once inside cells, the active coenzyme forms are resynthesized. Although some supplement manufacturers sell vitamins in their coenzyme forms, there is no benefit of consuming the coenzyme forms, as these are broken down during digestion and activated inside cells when needed.

how many fat soluble vitamins are absorbed when fat absorption is efficient?

about 40% to 90% of the fat-soluble vitamins are absorbed.

why should we consume water soluble vitamins daily?

because they are excreted quickly due to limited tissue storage capacity

why are vitamins essential in our diets?

because they cannot be synthesized in the human body or because their synthesis can be decreased by environmental factors.

Some people believe that consuming vitamins far in excess of their needs provides them with extra energy, protection from disease, and prolonged youth. They seem to think that if a little is good, then more must be better. A "one-a-day" type of multivitamin and mineral supplement usually contains less than two times the Daily Values of its components.

consuming large amounts of vitamins is not "better" for you, however there isn't a particular danger of toxicity unless a person is consuming many vitamin pills especially potent sources of vitamin A

what two classes are vitamins divided into

fat soluble vitamins and water soluble vitamins

The water-soluble vitamins, particularly thiamin, vitamin C, and folate, can be destroyed with...

improper storage and excessive cooking. Heat, light, exposure to the air, cooking in water, and alkalinity are factors that can destroy vitamins.

Unlike other water-soluble vitamins where are , B-6 and B-1?

in the liver and are not easily excreted in the urine

The ----- the food is, the more vitamins it will contain, but substantial amounts of vitamins can be lost from the time a fruit or vegetable is picked until it is eaten.

riper

bioavailability

the degree to which a consumed nutrient is absorbed and used by the body.

what does excretion of vitamins vary primarily on?

their solubility

describe the breakdown of B vitamins

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

what are the B vitamins

thiamin, riboflavin, niacin, pantothenic acid, biotin, vitamin B-6, folate, and vitamin B-12 (don't need to know B1 is thiamin or B2 is riboflavin... etc)

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

vitamin A, Vitamin A causes toxicity at intakes as little as two times the RDA

name some notable exceptions to having a strict dietary need for a vitamins

vitamin A, which we can synthesize from certain pigments in plants; vitamin D, synthesized in the body if the skin is exposed to adequate sunlight; niacin, synthesized from the amino acid tryptophan; and vitamin K and biotin, synthesized to some extent by the bacteria in the intestinal tract

which water soluble vitamins do we not need to worry about consuming more than the RDA orAI?

vitamin B-6 and vitamin B-12, which are stored in the liver. Although they are water-soluble, these two B vitamins may accumulate to toxic levels.

Name the characteristic nutrients for the dairy food group

vitamin D, Vitamin D functions in the body to maintain proper levels of calcium and phosphorous, thereby helping to build and maintain bones. Milk and soymilk (soy beverage) that are fortified with vitamin D are good sources of this nutrient. Other sources include vitamin D-fortified yogurt and vitamin D-fortified ready-to-eat breakfast cereals. calcium, protein, riboflavin, if fortified vitamin A and D added

Name the characteristic nutrients for the oils food group

vitamin E

what water soluble vitamins can cause toxic effects?

vitamin E and niacin vitamin B-6 and vitamin C, but only when consumed in very large amounts?(15 to 100 times human needs or more). Overall, vitamins are unlikely to cause toxic effects unless taken in supplement (pill) form.

Except for what vitamin, are fat-soluble vitamins are not readily excreted from the body?

vitamin K

what vitamin deficiency are people with fat-malabsorption conditions especially susceptible to?

vitamin K deficiency because body stores of vitamin K are lower than those of the other fat-soluble vitamins.

energy metabolism

vitamin thiamin, riboflavin, niacin, pantothenic acid, biotin, vitamin B-12