Copyright © 2012 Pearson Education, Inc. 10 C H A P T E R Nutrients Involved in Energy Metabolism and Blood Health and In Depth

© 2012 Pearson Education, Inc. Vitamins and Metabolism Vitamins and minerals  Are required for proper metabolism  Do not directly provide energy  Are necessary for obtaining energy from macronutrients  Often function as coenzymes

© 2012 Pearson Education, Inc. Vitamins and Metabolism Enzyme: a protein that accelerates the rate of a chemical reaction  Enzymes are required for all metabolic reactions Coenzyme: a molecule that combines with an enzyme to activate it  Some metabolic reactions require coenzymes PLAY Energy Metabolism

© 2012 Pearson Education, Inc. Vitamins and Metabolism

© 2012 Pearson Education, Inc. Vitamins and Metabolism

© 2012 Pearson Education, Inc. B-Vitamins The B-vitamins are especially important for energy metabolism The B-vitamins include: thiamin (B 1 )folate riboflavin (B 2 )vitamin B 12 niacinpantothenic acid vitamin B 6 biotin

© 2012 Pearson Education, Inc. B-Vitamins: Thiamin (Vitamin B 1 )  Coenzyme thiamin pyrophosphate is required for carbohydrate metabolism  Coenzyme for the metabolism of some fatty acids  Enriched foods, whole grains, and pork are good sources  Beriberi: deficiency of thiamin resulting in muscle wasting and nerve damage, and heart failure

© 2012 Pearson Education, Inc. B-Vitamins: Riboflavin (Vitamin B 2 )  Part of coenzymes involved in oxidation–reduction reactions  Part of the antioxidant enzyme glutathione peroxidase  Milk is a good source of riboflavin  Ariboflavinosis: riboflavin deficiency that causes sore throat and swollen mucous membranes

© 2012 Pearson Education, Inc. B-Vitamins: Niacin  Nicotinamide and nicotinic acid  Coenzyme assists with the metabolism of carbohydrates and fatty acids  Good sources: meat, fish, poultry, enriched bread products  Toxicity can result from supplements  Pellagra: severe niacin deficiency  4 Ds: dermatitis, diarrhea, dementia, and death

© 2012 Pearson Education, Inc. B-Vitamins: Vitamin B 6 (Pyridoxine)  Group of six related compounds  Part of a coenzyme for more than 100 enzymes, assists in amino acid metabolism, neurotransmitter, and assists in heme synthesis  Good sources: enriched cereals, meat, fish, poultry, starchy vegetables  Toxicity from supplements can result in nerve damage and skin lesions  Deficiency: anemia, elevated levels of homocysteine

© 2012 Pearson Education, Inc. B-Vitamins: Folate  Involved in DNA synthesis, amino acid metabolism, red blood cell synthesis  Critical for cell division of very early embryos  Good sources: ready-to-eat cereals, enriched bread products  Toxicity can mask vitamin B 12 deficiency  Deficiency: macrocytic anemia

© 2012 Pearson Education, Inc. Folate Deficiency: Neural Tube Defects A woman’s need for folate dramatically increases during pregnancy Folate is required for cell division and proper formation of the neural tube  The neural tube develops into the brain and spinal cord

© 2012 Pearson Education, Inc. Folate Deficiency: Neural Tube Defects The increased need for folate is critical very early (first 4 weeks) in pregnancy, frequently before a woman knows she is pregnant All women capable of becoming pregnant should consume an extra 400 µg/day of folate

© 2012 Pearson Education, Inc. Spina Bifida

© 2012 Pearson Education, Inc. Folate Deficiency: Anemia Anemia means “without blood”; any condition of low hemoglobin levels There are many types and causes of anemia Anemia “without blood” can be caused by a severe folate deficiency

© 2012 Pearson Education, Inc. B-Vitamins: Vitamin B 12 (Cobalamin)  Part of coenzymes for blood formation  Found only in animal-based foods  Deficiency can lead to pernicious anemia  Vegans are at risk for deficiency  Also occurs in people who consume very little vitamin B 12 in their diet  Symptoms are pale skin, reduced energy, fatigue, and neurological symptoms

© 2012 Pearson Education, Inc. B-Vitamins: Pantothenic Acid  Component of coenzymes for fatty acid metabolism  Deficiency is very rare  Biotin:  Part of coenzymes involved in the metabolism of carbohydrates, fat, and proteins  Deficiency is very rare

© 2012 Pearson Education, Inc. Iodine Iodine is a trace mineral  Critical for the synthesis of thyroid hormones  Thyroid hormones regulate body temperature, growth, and resting metabolic rate  Hypo, hyperthyroidism: Hashimoto’s, Grave’s disease  Good sources: saltwater fish, shrimp, iodized salt, milk and dairy products

© 2012 Pearson Education, Inc. Iodine Excess iodine  Blocks synthesis of thyroid hormones  Thyroid tries to make more hormones  Results in goiter: enlarged thyroid Iodine deficiency  Results in hypothyroidism and goiter  Cretinism: mental retardation from iodine deficiency during embryonic development

© 2012 Pearson Education, Inc. Chromium and Manganese Chromium is a trace mineral  Assists insulin as it transports glucose from the blood into the cells  Good sources: mushrooms, prunes, dark chocolate, nuts, whole grains Manganese is a trace mineral  Coenzyme involved in energy metabolism  Good sources: whole-grain foods, brown rice, pineapple, pine nuts, okra, spinach

© 2012 Pearson Education, Inc. Blood: Iron, Vit. K, Zinc & Copper Blood is the only fluid tissue in the body Functions  Transport of oxygen and nutrients to cells  Removal of waste products from cells Components of Blood  Erythrocytes: red blood cells  Transport oxygen through the body  Leukocytes: white blood cells of the immune system  Platelets: cell fragments that assist in blood clotting  Plasma: the fluid portion of the blood

© 2012 Pearson Education, Inc. Components of Blood  Erythrocytes: red blood cells  Transport oxygen through the body  Leukocytes: white blood cells of the immune system  Platelets: cell fragments that assist in blood clotting  Plasma: the fluid portion of the blood

© 2012 Pearson Education, Inc. Components of Blood

© 2012 Pearson Education, Inc. Vitamin K Vitamin K is a fat-soluble vitamin  Coenzyme for the synthesis of proteins involved in blood clotting  Healthful intestinal bacteria produce some vitamin K  Good sources: green leafy vegetables  Newborns are given vitamin K at birth

© 2012 Pearson Education, Inc. Iron Iron is a trace mineral Functions of iron  A component of the protein hemoglobin, which carries oxygen in erythrocytes  A component of myoglobin, which carries oxygen in muscle cells  A coenzyme involved in the metabolism of carbohydrates, fats, and proteins

© 2012 Pearson Education, Inc. Iron

© 2012 Pearson Education, Inc. Iron Recommended intake  Recommended Dietary Allowance (RDA) varies based on age and gender  8 mg/day for adult men  27 mg/day for pregnant women Sources of iron  Meat, poultry, fish, clams, oysters, enriched cereals and breads  Meat factor and vitamin C enhance absorption

© 2012 Pearson Education, Inc. Iron What if you consume too much iron?  Iron overdose is the most common cause of poisoning deaths in children  Toxicity symptoms: nausea, vomiting, diarrhea, dizziness, confusion  What if you don’t consume enough iron?  Iron deficiency is the most common nutrient deficiency in the world  High-risk people include infants, young children, preadolescent girls, premenopausal women, and pregnant women  There are three stages of iron deficiency

© 2012 Pearson Education, Inc. Iron

© 2012 Pearson Education, Inc. Zinc and Copper: trace minerals Functions of zinc:  Cofactor for hemoglobin production  Assists in energy metabolism, immune system and growth Sources of zinc  Red meats, some seafood, whole grains, enriched grains and cereals Functions of copper  Cofactor for energy metabolism  Coenzyme that assists in collagen production Sources of copper  Organ meats, seafood, nuts, seeds, whole-grain foods

© 2012 Pearson Education, Inc. In Depth: Dietary Supplements Dietary supplements are defined by the FDA as products taken by mouth containing a dietary ingredient intended to supplement the diet

© 2012 Pearson Education, Inc. In Depth: Dietary Supplements May contain: Vitamins Minerals Herbs or other botanicals Amino acids Enzymes Tissues from animal organs or glands …or a concentrate, a metabolite, a constituent, or an extract

© 2012 Pearson Education, Inc. Dietary Supplement Regulation  Categorized generally as foods, not drugs  Regulation is less rigorous than for drugs  FDA regulation of supplements marketing is currently in flux

© 2012 Pearson Education, Inc. What Consumers Should Know  FDA approval is not needed for marketing  Manufacturers are solely responsible for safety  Sellers are not required to show evidence of safety  There are no federal guidelines to ensure purity, safety, or composition  No rules limit serving sizes  Once a supplement is marketed, the FDA must prove it is unsafe for it to be removed from stores

© 2012 Pearson Education, Inc. Avoiding Web-Based Supplements Fraud Critically assess the Web site:  What is its purpose?  Is information accurate?  Does it use reputable references?  Who owns or sponsors the site?  Who wrote the information?  Is the information current?

© 2012 Pearson Education, Inc. Herbal Supplements  An herb (or botanical) is a plant or plant part used for its scent, flavor, and/or therapeutic properties  Consult your healthcare provider before using herbal supplements  Herbs may cause serious medical problems if used in large amounts  Avoid using herbs when pregnant or nursing, unless you have consulted a doctor  Active ingredients in many herbs and herbal supplements are not known

© 2012 Pearson Education, Inc. Should You Take Supplements?  Many people do not need supplements  Supplements are not substitutes for whole foods  Some individuals who may benefit from supplements include:  Vegans  Athletes  Infants and children  Pregnant teens and pregnant women  Elderly people  Convalescents

© 2012 Pearson Education, Inc. ABC News Nutrition Video Too Much of a Good Thing? New Vitamins and Cancer Study