Vitamins: Basic Concepts

All vitamins have been discovered because they were found to be essential nutrients that prevent deficiency diseases.

A vitamin is an organic compound that is required in small amounts for normal growth, development, and metabolism, but cannot be synthesized by the human body.

Fat-soluble vitamins (A, D, E, and K) can accumulate in the body and cause toxicity, whereas water-soluble vitamins (B and C) are generally excreted and do not build up to toxic levels.

<p>Ways to conserve vitamin content include reducing cooking time and water usage, storing foods properly, and using cooking methods that minimize vitamin destruction.</p> Signup and view all the answers

<p>Antioxidants protect cells from damage caused by free radicals, which are unstable molecules that can cause oxidative stress and contribute to chronic diseases.</p> Signup and view all the answers

<p>Vitamin enrichment and fortification involve adding vitamins to foods to restore nutrients lost during processing and to prevent deficiency diseases.</p> Signup and view all the answers

<p>James Lind's experiment demonstrated that citrus fruits could cure scurvy, leading to the discovery of vitamin C.</p> Signup and view all the answers

<p>Signs and symptoms of scurvy included fatigue, petechiae, skin bruising, gum swelling and bleeding, tooth loss, slow healing of wounds, and irritability.</p> Signup and view all the answers

<p>Because they consumed citrus fruits, including lemons, to prevent scurvy, and people often referred to citrus fruits as 'limes' during that time.</p> Signup and view all the answers

<p>He thought scurvy was a digestive system disorder that could be treated with substances associated with warm climates.</p> Signup and view all the answers

<p>It was coined by Casimir Funk, who discovered a substance in rice bran that he thought would cure beriberi, combining 'vita' (necessary for life) and 'amine' (a type of nitrogen-containing substance).</p> Signup and view all the answers

<p>Because babies grow and thrive on infant formulas, and very ill people can be kept alive for years on liquid synthetic feedings containing all known nutrients, including vitamins.</p> Signup and view all the answers

<p>About 0.005% (1.48 mg)</p> Signup and view all the answers

<p>Regulating a variety of body processes, including those involved in cell division and development, as well as the growth and maintenance of tissues.</p> Signup and view all the answers

<p>The body cannot synthesize the compound or make enough to maintain good health; the compound naturally occurs in commonly eaten foods; signs and symptoms of a health problem occur when the substance is missing from the diet; and good health is restored when the deficiency disorder is treated early by supplying the missing substance.</p> Signup and view all the answers

<p>A vitamin is the active form that functions in the body, whereas a provitamin is a precursor that needs to be converted into the active form.</p> Signup and view all the answers

<p>The body requires vitamins in milligram or microgram amounts, but it needs grams of macronutrients.</p> Signup and view all the answers

<p>Amounts of certain vitamins, although their use is being replaced by more precise measures.</p> Signup and view all the answers

<p>An oxidation reaction is when an atom or molecule loses one or more electrons, and if left uncontrolled, it can lead to a chain reaction causing excessive oxidation and damaging cells.</p> Signup and view all the answers

<p>More than one</p> Signup and view all the answers

<p>Antioxidants protect cells by giving up electrons to radicals, thereby preventing oxidation and damage to molecules such as polyunsaturated fatty acids and DNA.</p> Signup and view all the answers

<p>A vitamin-like essential nutrient</p> Signup and view all the answers

<p>Plants, animals, fungi, and even bacteria supply natural forms of vitamins in our diets.</p> Signup and view all the answers

<p>Vitamins participate in the chemical reactions that release energy from these macronutrients, but they are not a direct source of energy.</p> Signup and view all the answers

<p>A radical is a highly reactive substance with an unpaired electron that removes electrons from more stable molecules, causing damage or destruction.</p> Signup and view all the answers

<p>Some radical formation is necessary and provides benefits, such as stimulating normal cell growth and division, and helping white blood cells destroy infectious agents.</p> Signup and view all the answers

<p>Vitamins regulate various bodily functions, but they do not directly provide energy; instead, they participate in the chemical reactions that release energy from macronutrients.</p> Signup and view all the answers

<p>Antioxidants, like vitamin E, protect cells by giving up electrons to radicals, forming a more stable structure and preventing oxidation and damage to molecules.</p> Signup and view all the answers

<p>Natural vitamin E has more biological activity than synthetic vitamin E.</p> Signup and view all the answers

<p>Folic acid</p> Signup and view all the answers

<p>31%</p> Signup and view all the answers

<p>Because cells contain a supply of vitamins that can last for several days and possibly even years, and bacteria in the lower intestinal tract produce certain vitamins.</p> Signup and view all the answers

<p>Thiamin, riboflavin, niacin, and folic acid</p> Signup and view all the answers

<p>To improve vitamin intakes of Americans and protect against deficiency diseases.</p> Signup and view all the answers

<p>Fat-soluble vitamins</p> Signup and view all the answers

<p>They are concerned that it may lead to excessive intake of a few vitamins while reducing intake of others.</p> Signup and view all the answers

<p>Certain types of bacteria and algae</p> Signup and view all the answers

<p>Vitamins A and D</p> Signup and view all the answers

<p>The body's ability to eliminate excess water-soluble vitamins helps prevent toxicity, as these vitamins are not stored in the body and can be filtered out by the kidneys and eliminated in urine.</p> Signup and view all the answers

<p>The presence of fat in the small intestine, which stimulates the secretion of a hormone that causes the gallbladder to release bile, facilitating the absorption of fat-soluble vitamins.</p> Signup and view all the answers

<p>Diseases or conditions that affect the GI tract can reduce vitamin absorption, leading to deficiencies of these micronutrients.</p> Signup and view all the answers

<p>To enable small amounts of the vitamins to be absorbed, as their bodies are unable to absorb vitamins efficiently due to fat malabsorption.</p> Signup and view all the answers

<p>Such a diet can help supply the vitamin needs of most healthy people.</p> Signup and view all the answers

<p>To enhance the absorption of fat-soluble vitamins in these foods.</p> Signup and view all the answers

<p>Vitamin B-12 can be stored in the body for extended periods, making it an exception to the general rule that the body stores only limited amounts of most water-soluble vitamins.</p> Signup and view all the answers

<p>Reduced vitamin absorption can lead to deficiencies of micronutrients because the body may not be able to obtain adequate amounts of essential vitamins from the diet.</p> Signup and view all the answers

<p>Accumulating excess fat-soluble vitamins in the body can lead to toxicity, especially with vitamins A and D.</p> Signup and view all the answers

<p>Understanding the classification of vitamins as fat-soluble or water-soluble is important because it determines how the body absorbs, stores, and eliminates these micronutrients.</p> Signup and view all the answers

<p>Blanching denatures plant enzymes that cause deterioration. It can be stopped by plunging the produce into cold water.</p> Signup and view all the answers

<p>Bruised, wilted, shriveled, or decaying produce, or those with mold.</p> Signup and view all the answers

<p>Store at temperatures near freezing, in high humidity, and away from air.</p> Signup and view all the answers

<p>To reduce exposure to heat, alkaline substances, light, and air that can destroy vitamins.</p> Signup and view all the answers

<p>Retains water-soluble vitamins that would otherwise be lost in the cooking water.</p> Signup and view all the answers

<p>To conserve vitamins and nutrients found in the skin.</p> Signup and view all the answers

<p>Genetic makeup, growing conditions (including soil composition and sunlight exposure), and maturity at harvest.</p> Signup and view all the answers

<p>Older adults are at higher risk due to factors such as reduced intestinal absorption, higher excretion of vitamins, and other age-related health issues.</p> Signup and view all the answers

<p>They cook quickly, use minimal water, and reduce exposure to heat, water, and air.</p> Signup and view all the answers

<p>It does not reduce nutrient content more than conventional cooking methods.</p> Signup and view all the answers

<p>Depletion of the vitamin's body stores, followed by the onset of deficiency disease symptoms.</p> Signup and view all the answers

<p>To conserve vitamins; done by placing vegetables in a steamer basket over boiling water.</p> Signup and view all the answers

<p>Multivitamins usually contain less than two times the Daily Values of each micronutrient, making toxicity unlikely.</p> Signup and view all the answers

<p>Enzymatic activity.</p> Signup and view all the answers

<p>Retains nutrients, texture, flavor, and color.</p> Signup and view all the answers

<p>To ensure maximum vitamin retention.</p> Signup and view all the answers

<p>To preserve desirable flavors, colors, and textures.</p> Signup and view all the answers

<p>Due to increased requirements, impaired absorption, or higher excretion of vitamins.</p> Signup and view all the answers

<p>They cannot accept additional amounts of the micronutrient.</p> Signup and view all the answers

<p>Because cells store vitamins to some extent, and occasional low intakes are unlikely to cause deficiencies.</p> Signup and view all the answers

<p>Water-soluble vitamins are lost in the fluid that drips out during thawing.</p> Signup and view all the answers

<p>Fat enhances the body's absorption of fat-soluble vitamins.</p> Signup and view all the answers

<p>Damaged plant cells release an enzyme that produces brown pigments when exposed to air, and it can be prevented by sprinkling salt or sugar, coating with acidic solution, or covering with airtight plastic wrap and chilling.</p> Signup and view all the answers

<p>Canned foods can lose their vitamin content over time, especially if stored at high temperatures.</p> Signup and view all the answers

<p>The heating of food during canning can cause the destruction of certain vitamins.</p> Signup and view all the answers

<p>To conserve vitamin content, as peels and skins are rich in vitamins.</p> Signup and view all the answers

<p>Prolonged heating reduces vitamin content.</p> Signup and view all the answers

<p>To conserve vitamin content, as these methods use minimal water and heat.</p> Signup and view all the answers