151232 Micronutrients - Overview 2015 Full Slide Handout

7/23/2019 151232 Micronutrients - Overview 2015 Full Slide Handout

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Overview

2015

A/Prof Rozanne Kruger

151.232


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Task:

Match each micronutrient (column B) with

- a source from column A

- a role from column C

List any other names these micronutrients might be known


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Column B

Vit A Vit Bs Vit C

Vit !

Vit "

Calcium #luori$e

%o$ine

%ron &elenium

Column A (Source)

kiwifruit, currants

beef, seafood

water, tea

kelp, seafood

yeast, cereals,

animal products

carrots, pumpkin

bacteria, leafy greens

sunshine, salmon

dairy products

snapper, brazil nuts

Column C (Roles)

blood clotting

dental health

fertility, antioxidant

energy metabolism,

mental wellbeing

regulating growth

binding O2 reproduction, vision

calcium absorption

collagen synthesis

muscle contraction


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Vit A = carrots, pumpkin; reproduction, vision

Vit Bs = yeast, cereals; enery meta!olism, mental well"!ein Vit # = kiwi$ruit, currants; collaen synt%esis

Vit & = suns%ine, salmon; calcium a!sorption

Vit ' = !acteria, lea$y reens; !lood clottin

#alcium = dairy products; muscle contraction

(luoride = water, tea; dental %ealt%

)odine = kelp, sea$ood; reulatin rowt%

)ron = !ee$, s%ell$is%; !indin o*yen

+elenium = !rail nuts, snapper; $ertility, antio*idant


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Vit A: Retinol, Retinoic acid, Retinal, precursors are carotenes such as Beta-Carotene

Vit Bs:

Thiamin = B1 Riboflavin = B2 (activates B6, helps convert tryptophan to niacin) Niacin, nicotinic acid, nicotinamide, niacinamide = B3;

precursor is tryptophan Biotin

Pyridoxal phosphate, pyridoxine, pyridoxal, pyridoxamine = B6 Folate, folic acid, folacin, pteroylglutamic acid (PGA) Cobalamin = B12 (activated by Folate) Pantothenic Acid = B5Vit C: Ascorbic acid

Vit D: Cholecalciferol (D3 animals); ergocalciferol (D2 plants);1,25 dihydroxy vit D = calctriol precursor is cholesterol

Vit E: alpha-tocopherol (only active form of Vit E in humans)Vit K: phylloquinone, menaquinone, menadione, naphthoquinone


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-o !e a!le to classi$y t%e nutrients

-o !e a!le to descri!e t%e eneral $unctions o$ t%e vitamins andminerals

-o distinuis% !etween t%e properties o$ t%e various types o$vitamins

-o identi$y clearly t%e roles o$ t%e vitamins and minerals inmeta!olism

Copyright 2005 Wadsworth Group, a division of Thomson Learning


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)noranic nutrients

.inerals /eulate .aintain

ater

utrient -ransport

/eulate temperature

-ake part in c%emical reactions

/emove waste


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Oranic nutrients

#ar!o%ydrates 3rovide 4nery +ave 3rotein Assist in Burnin o$ $at

6ipids

Assist in makin o$ 4(As a!sorption o$ (at solu!le Vitamins 3rovide4nery

3roteins

Build /epair provide enery reulate

Vitamins

/eulate 3rovide 4nery 3rotect Assist in !ody $unctions


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-%e vitamins are oranic su!stances, re7uired in tiny amounts,

t%at are essential $or %ealt%, and per$orm at least one speci$icmeta!olic $unction and must !e provided in t%e diet 8cannot!e synt%esied9

'ita = li$e

amine = containin nitroen

#asimir (unk : 112

8later dropped


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B vitamins names and functions

Thiamin B1 Metabolism of energy yieldingRiboflavin* B2 intermediates via red/ox reactions

Niacin B3 Coenzymes in energy metabolismPyridoxine* B6 TransaminationCobalamin B12 Transmethylation*Folate B9 Methylation reactionsPantothenic acid B5 Constituent of coenzyme ABiotin B10 Carboxylation using coenzyme A


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+tructure: )ndividual units " not linked molecules e>>lucose amino acids

(unction: not enery yieldin : t%ey assist enymesused in enery meta!olism

(ood #ontents: amount inested : measured inmicrorams 89 and millirams 8m9


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Bio"availa!ility

is t%e proportion o$ t%e nutrient t%at is diested, a!sor!ed andmeta!olied t%rou% normal pat%ways,

is not represented simply !y t%e amount t%at is contained in a $ood>


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4$$iciency o$ diestion transit time

3revious nutrient intake and nutritional status Ot%er $oods consumed simultaneously

(ood preparation met%od

+ource o$ t%e nutrient : synt%etic or natural

?ealt% status

Bioavailability in turn affects micronutrient requirements


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3recursor provitamin

+ome vitamins in $oods are in an inactive $orm known asprecursors or pro"vitamins

)n vivo precursor active vitamin

.easurin vitamin intake = active vitamin @ potentialamount availa!le in precursor $orm

#oenyme

A su!stance, usually a vitamin, t%at must !e present!e$ore certain enymes can $unction

+ome vitamins serve primarily as coenymes aidin in t%e

action o$ enymes


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Apo"enyme

An inactive protein portion o$ an enyme, eit%er aco$actor 8a metallic ion9 or a coenyme 8a vitamin9

must !e attac%ed to it to $orm an active enyme

?olo"enyme

An active enyme made up o$ a protein part 8apo"enyme9, and eit%er a co$actor 8a mineral9 or a

coenyme 8a vitamin9


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#o"enymes : vitamins minerals#o"$actors : minerals

.ost B vitamins and minerals $orm part o$ co"enyme comple*est%at ena!le enymes to synt%esie compounds or to dismantlecompounds

to assist enymes to release enery

to assist wit% meta!olism e>> vit B

to $acilitate cell multiplication e>> $olate

.etalloenymes 8(e, n9

-%e vitamin portion o$ t%e co"enyme !inds to t%e enyme

it%out t%e co"enyme t%e enyme cannot work


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#oenyme $unction

Copyright 2005 Wadsworth Group, a division of Thomson Learning


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Oranic nature

#an !e destroyed t%us %andle wit% care, storae,cookin, O2 and sunli%t

?eatin 8B19, CV rays$luorescent li%t 8B29, O*idation viacuttinprocessin 8#9,

+olu!ility

in$luences diestion, a!sorption transport, storae and

e*cretion: ?ydrop%ilic 8prot #?O; water solu!le vitamins = D Bvits #9

: ?ydrop%o!ic 8lipid; $at solu!le vitamins = A,&,4,'9


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-o*icity


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Dose effects

3%ysioloical e$$ect

w%en a dose o$ a nutrient at a level w%ic% can easily !eac%ieved t%rou% diet provides a normal !lood concentration>

3%armacoloical e$$ect w%en a lare dose at a level w%ic% could only !e ac%ieved

t%rou% supplementation provides a !lood concentration w%ic%

is in e*cess o$ t%e normal rane and acts like a dru


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ater soluble

8B vits #9

#at soluble

8A&4'9

A!sorption &irect in !lood (irst in lymp%, t%en !lood

-ransport -ravel $reely /e7uire protein carriers

+torae #irculate $reely in water"

$illed parts

+tored in cells associated wit%

$at4*cretion 'idneys detect remove

e*cess in urine

6ess readily e*creted, remain in

$at"storae sites

-o*icity 3ossi!le to reac% to*ic levels

8$rom supplements9

6ikely to reac% to*ic levels

8$rom supplements9/e7uirements eeded in $re7uent doses 81

to F days9

eeded in periodic doses

8weeks or even mont%s9


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)noranic su!stances : no car!ons

.acro elements : present in %i% amounts 8G50ppm9 inanimal tissue

.icro elements : trace elements : present in small amounts 8H50ppm9 80>005I9 o$ !ody wei%t

&e$iciency o$ )odine : representin 1 part per D0 million o$ !odywei%t = more de!ilitatin t%an a de$iciency o$ calcium w%ic%accounts $or 2I 82 parts per %undred9 o$ !ody wei%t

#annot !e synt%esied

J?i%erK in animal $oods t%an plant $oods and morereadily a!sor!a!le 8superiorE9


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-o*icity

)ndividual variation &ietary needs

Variation

e$$ects


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.aintenance o$ Acid"!ase !alance

Bioloical reactions depend on narrow rane o$ p? 8acidity alkalinity9

)nactivation o$ enymes result in cellular starvation and deat%

Acid"$ormin elements 8not to do wit% taste9

#%lorine, sulp%ur, p%osp%orus 8presence o$ elements9 .eat, es, cereals

Base"$ormin elements $oods +odium, potassium, manesium, calcium

(ruits, veeta!les, nuts

eutral $oods .ilk, suar, starc%, $ats oils


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.aintenance o$ Acid"!ase !alance

.i*ed diets usually %ave more acid"$ormin elements

#ounteract : #O2, urine

Bu$$ers in !lood 8react wit% e*cess acid !ase : neutralie9

)ne$$ective !u$$erin :

Alkalosis : !lood too alkaline Acidosis : !lood too acid

Csually no pro!lems due to dietary intakes


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#atalyst $or !ioloical $unctions

+u!stance t%at speeds up or $acilitates a reaction t%at would occur at amuc% slower rate t%an wit%out it

#o$actors are su!stances t%at are essential $or a iven reaction to occur

calcium catalyst $or !lood clottin !ut not part o$ clot

-%iamine contain sulp%ur and vit B12 contain co!alt


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#omponents o$ essential !ody compounds

?ormones

-%yro*in : )

?! : (e

?#l " #l

4nymes .etallo"enymes e>> enery release enyme : #u (e

3rotein splittin enyme " n


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-ransmission o$ nerve impulses

As an impulse is conducted alon nerve $i!res, permea!ility

c%anes, allowin potassium to leave t%e cell> At same time sodium enters eac% cell, !ut is 7uickly pumped

out : resultin in temporary c%ane o$ electrical c%are on

cell mem!rane

-%is c%are c%anes t%e permea!ility o$ t%e ne*t sement o$t%e $i!re : sendin t%e messae alon

#oncentration o$ a and ' essential

eurotransmitter A#% is needed at t%e Lunction o$ eac% $i!re "reulated !y #alcium


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/eulation o$ #ontractility o$ muscles

#omposition o$ intercellular $luid is critical

#alcium : stimulate muscle contraction

+odium, potassium, manesium : e*ert rela*in e$$ect

Balance is critical : usually rat%er %ormonal t%an dietary

+odium, potassium, manesium, calcium


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Mrowt% o$ !ody tissue

6are concentrations

Bone, teet% : #alcium, p%osp%orus

4nery release or reactions resultin in synt%esis

3%osp%orus, manesium, iron

.aintenance o$ water !alance

Between $luid compartments )ntracellular and e*tracellular

+odium, potassium


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151232 Micronutrients - Overview 2015 Full Slide Handout