Micronutrients

Chapter 08

Micronutrients

Overview of the Micronutrients:Overview of the Micronutrients:Lecture OutlineLecture Outline

•• VitaminsVitamins–– Absorption & StorageAbsorption & Storage–– ToxicityToxicity

–– Preservation in FoodPreservation in Foodss

•• MineralsMinerals–– Absorption & StorageAbsorption & Storage–– ToxicityToxicity–– Preservation in FoodsPreservation in Foods

•• Functional RolesFunctional Roles–– Enzymes, coenzymes & Enzymes, coenzymes &

cofactorscofactors–– Fluid & Electrolyte BalanceFluid & Electrolyte Balance–– Antioxidant SystemsAntioxidant Systems–– Building BonesBuilding Bones–– Energy MetabolismEnergy Metabolism–– Blood HealthBlood Health

•• Nutrition and Your HealthNutrition and Your Health–– CholineCholine: The Newest : The Newest

Vitamin?Vitamin?

Vitamins OverviewVitamins Overview

•• CarbonCarbon--containing substances needed in containing substances needed in small amounts by the bodysmall amounts by the body

•• Essential: canEssential: can’’t be synthesized by bodyt be synthesized by body

•• To be a vitamin:To be a vitamin:

–– 1.) Body can1.) Body can’’t make enough to t make enough to maintain healthmaintain health

–– 2.) Absence 2.) Absence →→ deficiency that can be deficiency that can be cured if vitamin is resuppliedcured if vitamin is resupplied

Vitamins ClassificationVitamins Classification

•• Fat Soluble VitaminsFat Soluble Vitamins–– Vitamin AVitamin A–– Vitamin DVitamin D–– Vitamin EVitamin E–– Vitamin KVitamin K

•• Water Soluble Water Soluble Vitamins & Vitamins & CholineCholine–– ThiaminThiamin–– RiboflavinRiboflavin–– NiacinNiacin–– PantothenicPantothenic acidacid–– BiotinBiotin–– Vitamin BVitamin B--66–– FolateFolate (folic acid)(folic acid)–– Vitamin BVitamin B--1212–– Vitamin CVitamin C–– CholineCholine 44

Fat Soluble Vitamins: Fat Soluble Vitamins: Absorption & StorageAbsorption & Storage

FatFat--soluble:soluble:

–– Absorbed with dietary fatAbsorbed with dietary fat

–– Anything interfering with fat Anything interfering with fat absorption will impair fat soluble absorption will impair fat soluble absorptionabsorption

Fat Soluble Vitamin ToxicityFat Soluble Vitamin Toxicity

•• FatFat--soluble:soluble:

–– Not readily excreted from the bodyNot readily excreted from the body

–– Toxicity by vitamin A most Toxicity by vitamin A most frequently observedfrequently observed

Vitamin toxicity most frequently from supplemental Vitamin toxicity most frequently from supplemental sources: not foodssources: not foods

Water Soluble Vitamins: Water Soluble Vitamins: Absorption & StorageAbsorption & Storage

WaterWater--soluble:soluble:

–– Absorbed primarily in small intestineAbsorbed primarily in small intestine

–– Transported to liver via portal vein & Transported to liver via portal vein & distributed to body tissuesdistributed to body tissues

–– Inside cells: active coenzymes Inside cells: active coenzymes resynthesizedresynthesized

Water Soluble Vitamin ToxicityWater Soluble Vitamin Toxicity

•• WaterWater--soluble:soluble:

–– Excess excreted in urineExcess excreted in urine

–– Exception: B6 & B12 stored in liverException: B6 & B12 stored in liver

Vitamin Preservation in FoodsVitamin Preservation in Foods

•• WaterWater--soluble particularly susceptible to soluble particularly susceptible to destruction by heat, light, air exposure, destruction by heat, light, air exposure, cooking in water & alkalinitycooking in water & alkalinity

•• More ripe a fruit and vegetable = more More ripe a fruit and vegetable = more vitamin contentvitamin content

•• Freezing can help retain nutrients (frozen Freezing can help retain nutrients (frozen foods often blanched first) foods often blanched first) ↑↑ vitamin vitamin contentcontent

MyPlateMyPlate: : Sources of Vitamins & Sources of Vitamins & CholineCholine

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

MyPlate:Sources of Vitaminsand Choline

Grains• Thiamin• Riboflavin• Niacin• Folic acid

Vegetables• Vitamin A• Vitamin K• Folate• Vitamin C

Fruits• Vitamin A• Vitamin C

Dairy• Vitamin D• Riboflavin• Vitamin B-12• Choline

Protein• Thiamin• Riboflavin• Niacin• Biotin• Vitamin B-6• Vitamin B-12• Choline

FruitsGrains

VegetablesProtein

Dairy

ChooseMyPlate.gov

Minerals OverviewMinerals Overview•• Individual chemical components: canIndividual chemical components: can’’t be t be

broken down furtherbroken down further

•• Essential when:Essential when:

–– Dietary inadequacy Dietary inadequacy →→ physiological or physiological or structural abnormalitystructural abnormality

–– And addition to diet reinstates healthAnd addition to diet reinstates health

•• Categorized on amount needed per day:Categorized on amount needed per day:

–– Major: need 100 mg+ per dayMajor: need 100 mg+ per day–– Trace: need < 100 mg per dayTrace: need < 100 mg per day

Minerals ClassificationMinerals Classification

•• Major minerals:Major minerals:

–– SodiumSodium–– PotassiumPotassium–– ChlorideChloride–– CalciumCalcium–– PhosphorusPhosphorus–– MagnesiumMagnesium–– SulfurSulfur

•• Trace minerals:Trace minerals:–– IronIron–– ZincZinc–– SeleniumSelenium–– IodideIodide–– CopperCopper–– FluorideFluoride–– ChromiumChromium–– ManganeseManganese–– MolybdenumMolybdenum

Minerals: BioavailabilityMinerals: Bioavailability

Bioavailability affected by:

• Age

• Gender

• Genetic variables

• Nutritional status

• Diet

• Prescription drugs

Minerals: AbsorptionMinerals: Absorption

•• PhyticPhytic acid & oxalic acid acid & oxalic acid ↓↓ some mineral absorptionsome mineral absorption

•• ↑↑ fiber diets can fiber diets can ↓↓ absorption of Fe, Znabsorption of Fe, Zn

•• Vitamin C intake Vitamin C intake ↑↑ iron absorptioniron absorption

•• Vitamin D intake Vitamin D intake ↑↑ calcium absorptioncalcium absorption

•• Excess of one mineral can Excess of one mineral can ↓↓ absorption of another:absorption of another:–– ↑↑↑↑ Zn intake Zn intake ↓↓ Cu absorptionCu absorption

Minerals: StorageMinerals: Storage

• Stored in various tissues

• Some remain in bloodstream

• Ca, Phos, Mg, Fl stored in bone

• Fe, Cu, Zn & some trace stored in liver

• Others stored in muscle tissue, organs, glands

Minerals: ToxicityMinerals: Toxicity

•• Supplements pose biggest Supplements pose biggest problem for toxicityproblem for toxicity

•• Harmful interactions with Harmful interactions with other nutrients can occurother nutrients can occur

•• Look for brands with USP for Look for brands with USP for supplementssupplements

Minerals: Preservation in FoodsMinerals: Preservation in Foods

•• Not typically lost from animal foods Not typically lost from animal foods during processingduring processing

•• Are lost from plant foods during Are lost from plant foods during processingprocessing

•• Refined grains = Refined grains = ↓↓ levels of vitamin levels of vitamin E, B vitamins & trace mineralsE, B vitamins & trace minerals

•• Refined grains = Fe added but Se, Refined grains = Fe added but Se, Cu, Zn not added backCu, Zn not added back

MyPlateMyPlate: Sources of Minerals: Sources of MineralsCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

MyPlate:Sources of Minerals

FruitsGrains

VegetablesProtein

Dairy

ChooseMyPlate.gov

Grains• Sodium chloride• Calcium(fortifiedproducts)

• Phosphorus• Magnesium• Iron• Zinc• Copper• Selenium• Chromium

Vegetables• Potassium• Magnesium

Fruits• Potassium• Boron

Protein• Sodium chloride

(processedfoods)

• Potassium• Phosphorus• Magnesium• Selenium• Iron• Zinc• Copper

• Zinc

Dairy• Calcium• Phosphorus

Functional RolesFunctional Rolesof Micronutrients: Overviewof Micronutrients: Overview

•• Enzymes, coenzymes & cofactorsEnzymes, coenzymes & cofactors

•• Fluid & Electrolyte BalanceFluid & Electrolyte Balance

•• Antioxidant SystemsAntioxidant Systems

•• Building BonesBuilding Bones

•• Energy MetabolismEnergy Metabolism

•• Blood HealthBlood Health


•• Enzymes, coenzymes & cofactorsEnzymes, coenzymes & cofactors

–– Enzymes: catalysts for biochemical reactionsEnzymes: catalysts for biochemical reactions

–– Enzymes typically made of proteinsEnzymes typically made of proteins

–– Require a cofactor for biological activityRequire a cofactor for biological activity

–– Minerals: inorganic molecules are Minerals: inorganic molecules are cofactorscofactors

–– Vitamins: organic molecules are Vitamins: organic molecules are coenzymescoenzymes

–– The BThe B--vitamins function as coenzymesvitamins function as coenzymes


•• Fluid & Electrolyte BalanceFluid & Electrolyte Balance

–– Balance between intracellular and Balance between intracellular and extracellular waterextracellular water

–– Includes:Includes:•• SodiumSodium•• PotassiumPotassium•• ChlorideChloride•• PhosphorusPhosphorus


•• Antioxidant SystemsAntioxidant Systems

–– Aid in antioxidant function as Aid in antioxidant function as components of antioxidant enzymescomponents of antioxidant enzymes

–– Includes:Includes:•• Vitamin EVitamin E•• Vitamin CVitamin C•• Vitamin A and Vitamin A and carotenoidscarotenoids•• SeleniumSelenium


•• Building BonesBuilding Bones

–– Bone is a living, dynamic tissueBone is a living, dynamic tissue

–– Includes:Includes:•• Vitamin DVitamin D•• Vitamin KVitamin K•• CalciumCalcium•• PhosphorusPhosphorus•• MagnesiumMagnesium•• FluorideFluoride


•• Energy MetabolismEnergy Metabolism

–– Vitamins & minerals do not yield Vitamins & minerals do not yield energyenergy

–– They participate as cofactors or They participate as cofactors or coenzymes in energycoenzymes in energy--yielding yielding reactionsreactions


•• Immune FunctionImmune Function

–– Immunity defends against pathogensImmunity defends against pathogens

–– Include: skin, intestinal cells, WBCInclude: skin, intestinal cells, WBC

–– Includes:Includes:•• Vitamin A, D, EVitamin A, D, E•• Some B vitaminsSome B vitamins•• Vitamin CVitamin C•• Chromium, copper, selenium, iron & zincChromium, copper, selenium, iron & zinc

Functional Roles Functional Roles of Micronutrients: Overviewof Micronutrients: Overview

•• Blood HealthBlood Health

–– Transport oxygen, nutrients & Transport oxygen, nutrients & wastewaste

–– Includes:Includes:•• Blood clotting: Vitamin K & calciumBlood clotting: Vitamin K & calcium•• Blood cell health: iron, copper, Blood cell health: iron, copper,

folatefolate, vitamin B6 and vitamin B12, vitamin B6 and vitamin B12

Micronutrients

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