Chapter 8 The WaterSoluble Vitamins Which statement is

Chapter 8 The Water-Soluble Vitamins

Which statement is true? Vitamin deficiencies are rare in the United States. Vitamins are necessary in many biochemical reactions in the body. It generally takes longer to develop a deficiency of a fat-soluble vitamin than a deficiency of a water soluble vitamin. Copyright 2010, John Wiley & Sons, Inc.

The Vitamins (water and fat soluble) Copyright 2010, John Wiley & Sons, Inc.

Vitamin Talk n n Vitamins are organic compounds essential in the diet to promote growth and health maintenance. Water-soluble vitamins include the B vitamins and vitamin C. Fat-soluble vitamins include A, D, E and K. B vitamins were originally thought to be one chemical substance but are actually many different substances. That is the reason for B 1, B 2, B 12, etc. Copyright 2010, John Wiley & Sons, Inc.

Which statement concerning vitamins is incorrect? a) vitamins are organic compounds b) If a vitamin is not provided by the diet, the body will synthesize it c) vitamins are needed in small amounts than macronutrients d) vitamins are essential for growth, reproduction and health Copyright 2010, John Wiley & Sons, Inc.

Fortified and Enriched Foods n n Vitamins may be lost when food is processed. When these vitamins are added back to the processed food at the same or higher level, the food is said to be? a. Enhanced b. Fortified c. Enriched d. Supplemented Fortification: process of adding nutrients to foods. The added nutrients are generally not found in the food, ie) fortifying orange juice with calcium. Enrichment: adding nutrients back to foods that have lost nutrients due to processing. Ie) addition of B vitamins to white rice. Sometimes this process puts people above FDA guidelines. Ie, almost all breakfast cereals are fortified with iron and calcium, and many other vitamins not deficient in the U. S. diet. Copyright 2010, John Wiley & Sons, Inc.

Dietary Supplements n n Dietary supplements can be another source of vitamins in the modern diet. Dietary supplements cannot replace the benefits of a diet containing a wide variety of foods: epidemiological studies show that people who eat more fruits/veggies have a lower incidence of a host of chronic diseases. These same benefits are not duplicated by taking supplements of nutrients found in these foods. Dietary supplement production is not supervised by the FDA. Copyright 2010, John Wiley & Sons, Inc.

Absorption of Vitamins Copyright 2010, John Wiley & Sons, Inc.

Bioavailability of Vitamins n n n Vitamins must be absorbed by the body in order to perform their functions. Approximately 40 -90% of vitamins are absorbed in the small intestine. Fat-soluble vitamins require fat in the diet to be absorbed and water-soluble vitamins may require transport molecules or specific molecules in the GI tract. Some vitamins are absorbed in inactive provitamin or vitamin precursor forms that must be converted into active forms by the body. The form in which a vitamin is presented can impact its absorption and utilization. Copyright 2010, John Wiley & Sons, Inc.

Which of the following terms is used to describe how much of a vitamin

Thiamin: B 1 n n Thiamin was the first B vitamin to be identified and is also called B 1. The disease resulting from deficiency is beri-beri and present in east Asia for over 1000 years. It came to western medical attention in colonial Asia in the 19 th century. Why there? Copyright 2010, John Wiley & Sons, Inc.

Thiamin deficiency n Beri-beri: a disease of the muscles and nervous system characterized by n Depression and weakness (after just 10 days on thiamin free diet). n Neuromuscular symptoms such as paresthesia (spontaneous sensations, such as itching, burning, etc. ) in-coordination … explained by lack of acetylcholine. n enlargement of the heart… the reason is not well understood. Copyright 2010, John Wiley & Sons, Inc.

B 1 : Functions n Thiamin assists in q q q energy production from glucose. carbohydrate metabolism and the production of ribose (necessary for RNA) the health of the nervous system (synthesis of acetylcholine, a neurotransmitter) Copyright 2010, John Wiley & Sons, Inc.

Thiamin Deficiency n n n Deficiency is rare in the United States because most foods are now vitamin enriched (previously common in places with predominantly a polished rice diet). Today, beri occurs mostly in patients who abuse alcohol. Drinking heavily can lead to poor nutrition, and excess alcohol makes it harder for the body to absorb and store B 1 Beriberi can occur in breast-fed infants when the mother's body is lacking in thiamin Copyright 2010, John Wiley & Sons, Inc.

Thiamine Deficiency Wernicke-Korsakoff syndrome q q confusion, psychosis, confabulation, and impaired retentive memory. In severe cases the patient may slip into a coma. (korsakoff syndrome refers to the retrograde amnesia) Carl Wernicke Copyright 2010, John Wiley & Sons, Inc.

Alcohol: Toxicity is dose dependent Copyright 2010, John Wiley & Sons, Inc.

A primary function of thiamin in the body is to: clot blood regulate cell differentiation increase uptake of iron by hemoglobin facilitate production of energy from glucose Copyright 2010, John Wiley & Sons, Inc.

Thiamin Copyright 2010, John Wiley & Sons, Inc.

Riboflavin (B 2) n n n Dairy products are a good source of riboflavin. Why is milk often supplied in opaque containers? Riboflavin is easily destroyed by heat and exposure to light. Plant sources of riboflavin include mushrooms, broccoli, asparagus, whole grains and green, leafy vegetables. Animal sources include red meat, poultry and fish. Milk is the best source in the American diet. Copyright 2010, John Wiley & Sons, Inc.

Flavin adenine dinucleotide (FAD) Copyright 2010, John Wiley & Sons, Inc.

Riboflavin forms active coenzymes that do all the following except help produce energy from carbohydrate, protein and fat. function as electron carriers. function in the citric acid cycle. send messages between nerve cells. Copyright 2010, John Wiley & Sons, Inc.

B 2 deficiency • • Deficiency leads to ariboflavinosis : injuries are slow to heal, inflammation of eyes, lips, mouth, tongue (tissues that grow most rapidly). Deficiency develops after ~ 2 months of B 2 poor diet…. Copyright 2010, John Wiley & Sons, Inc.

Riboflavin Copyright 2010, John Wiley & Sons, Inc.

Niacin (B 3) n n n Meat and fish are good sources. The emergence of deficiency states can be traced to the cultivation of corn as the dietary staple. Today, Niacin is added to enriched flours in North America. Carpenter found in 1951 that niacin in corn is biologically unavailable, and can be released only in very alkaline lime water of p. H 11. Niacin can be synthesized in the body from the essential amino acid tryptophan if the diet is adequate in tryptophan (milk, eggs, etc). Niacin plays an important role in the production of energy and in general metabolism. Copyright 2010, John Wiley & Sons, Inc.

Niacin Deficiency n A niacin deficiency disease is pellagra which causes progressive mental and physical deterioration. n Advanced pellagra’s symptoms include the 3 D’s: dermatitis, diarrhea and dementia. Niacin toxicity from overuse of niacin supplements can result in flushing of the skin, elevated blood pressure, cardiac arrhythmia, nausea, vomiting, elevated blood sugar levels and impaired liver function. n Copyright 2010, John Wiley & Sons, Inc.

Pellagra occurs when _____ is the staple grain in the diet and the diet

Niacin Copyright 2010, John Wiley & Sons, Inc.

Biotin Discovered when rats fed protein derived from raw egg developed hair loss, dermatitis, and neuromuscular symptoms. n Avidin, a protein in raw eggs tightly binds biotin and prevents absorption. n Functions in energy production form the citric acid cycle n Deficiency is rare, but observed in those receiving tube feeding or those who are malnourished. n Dose=200 mg qd n

Pantothenic Acid (B 5) n n Panthethinc acid from greek pantothen (meaning ‘from everywhere’) The wide distribution makes deficiency rare. Particularly high in meat, eggs, whole grains, legumes. Part of acetyl-Co. A (for energy production) Copyright 2010, John Wiley & Sons, Inc.

Pantothenic Acid Copyright 2010, John Wiley & Sons, Inc.

Pantothenic acid (B 5) is abundant in: meat eggs whole grains All answer choices

Vitamin B 6 n n n Vitamin B 6 is also called pyridoxine Vitamin B 6’s role in amino acid metabolism distinguishes it from the other B vitamins. (needed to synthesize nonessential a. a. by transamination). B 6 is easily lost via exposure to heat, light, processing. Not usually added back. Vitamin B 6 deficiency may result in anemia due to impaired hemoglobin synthesis (pyridozil phosphate) Both B 6 and B 12 are needed to synthesize the myelin coat of nerve cells. And essential for normal nerve cell transmission. Copyright 2010, John Wiley & Sons, Inc.

Vitamin B 6 and cardiovascular risk n Individuals with high homocysteine levels n n develop atherosclerosis at an early age B 6 helps in the breakdown of this amino acid Folate and B 12 are also required in this important pathway. Copyright 2010, John Wiley & Sons, Inc.

Vitamin B 6 does not perform which of the following roles? a) It is vital in the formation of non -essential amino acids. b) It is required for the synthesis of hemoglobin. c) It is necessary in collagen formation. d) Large doses can reduce high blood homocysteine levels which is a risk factor for cardiovascular disease. Copyright 2010, John Wiley & Sons, Inc.

Vitamin B 6 Copyright 2010, John Wiley & Sons, Inc.

Many B vitamins are essential for the metabolism of energy yielding nutrients. They perform this function by binding to and promoting the activity of enzymes. When B vitamins perform in this way, they are ____? provitamins transport proteins coenzymes hormones Copyright 2010, John Wiley & Sons, Inc.

Folate or Folic Acid n n n Folate coenzymes are needed for DNA synthesis and the metabolism of some amino acids. Low folate intake in early pregnancy is associated with an increased risk of neural tube defects. Low folate intake has been associated with an increased risk of heart disease related to the metabolism of the amino acid homocysteine. Copyright 2010, John Wiley & Sons, Inc.

Folate Deficiency and Neural Tube Defects Copyright 2010, John Wiley & Sons, Inc.

Macrocytic Anemia and Folate Deficiency Copyright 2010, John Wiley & Sons, Inc.

Folate deficiency symptoms are less of a problem recently because: grain products have been fortified with folate more people are taking supplements more people are drinking lowfat milk green tea is more popular Copyright 2010, John Wiley & Sons, Inc.

Folate or Folic Acid Copyright 2010, John Wiley & Sons, Inc.

Vitamin B 12 n n n Pernicious anemia is a form of anemia that does not respond to iron supplementation. Vitamin B 12 is necessary for the proper absorption of iron in the body. Excessive intake of folic acid can mask B 12 deficiencies. Vitamin B 12 is most readily absorbed from animal products. Vegan diets need to be supplemented with readilyabsorbable forms of B 12. Atrophic gastritis may lead to B 12 deficiencies. Copyright 2010, John Wiley & Sons, Inc.

Absorptio n of Vitamin B 12 Copyright 2010, John Wiley & Sons, Inc.

Vitamin B 12 Copyright 2010, John Wiley & Sons, Inc.

Vitamin C n n Vitamin C is also known as ascorbic acid or ascorbate. Functions include: q q n an antioxidant in the body helps maintain the immune system is important in the production of collagen and aids in iron absorption. Vitamin C in foods can be destroyed by oxygen, light and heat, as well as contact with copper or iron cookware. Copyright 2010, John Wiley & Sons, Inc.

Deficiency Vit C leads to scurvy Copyright 2010, John Wiley & Sons, Inc.

Which group is at risk for developing vitamin C deficiency? Sailors in the 1300

Which is the best source of vitamin C? a) green pepper b) milk c)

Vitamin C Copyright 2010, John Wiley & Sons, Inc.

How Antioxidants Work Copyright 2010, John Wiley & Sons, Inc.

Which lifestyle factor increases the requirement for vitamin C? drinking alcohol exercising frequently and intensely smoking cigarettes eating a diet high in fiber Copyright 2010, John Wiley & Sons, Inc.

Summary of Water-Soluble Vitamins and Choline Copyright 2010, John Wiley & Sons, Inc.

Benefits and Risks of Water. Soluble Vitamin Supplements Copyright 2010, John Wiley & Sons,

Beriberi is a disease caused by lack of _______ in the diet. riboflavin thiamin

Which disease is caused by a niacin deficiency? a) ariboflavinosis b) beri c) pellagra

Which is the TRUE statement about niacin? It can be synthesized in the body from the amino acid, tryptophan. Eggs are a good source of preformed niacin. Heat and light easily destroy it. Corn has a protective effect against niacin deficiencies. Copyright 2010, John Wiley & Sons, Inc.

Another name for vitamin B 6 is a) pantothenic acid b) pyridoxine c) pyruvate

Finding Vitamins in Foods Copyright 2010, John Wiley & Sons, Inc.

Chapter 8 Copyright 2010 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the . Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information herein. Copyright 2010, John Wiley & Sons, Inc.