NUTRITION. The nutrient requirements of the child are influenced by; Body composition, the rate of growth Composition of new growth Vary with the child’s

NUTRITION

NUTRITION

The nutrient requirements of the child are influenced by;

Body composition, the rate of growthComposition of new growth Vary with the child’s age Important during early postnatal life

NUTRITION

Growth rate; higher in early infancyBody composition ; e.g. brain accounts

for 10% of body weight. (a: 2%) needs 44% of total energy (a: 19%)

Composition of new growth : e.g. Fat accounts for about 40% of weight gain between birth and 4 months but only 3% between ages 24 and 36 months. (pr, 11% and 21%)

NUTRITION

Because of the high nutrient requirements for growth and body composition, the young infant is especially vulnerable to undernutrition.

Slowed physical growth rate; early and prominent sign of undernutrition in the young infant.

major determinants of energy: (6-12 months)

Basal metabolism 50%Metabolic response to food 5%Physical activity 25%Growth 12%

(5% after 1 year)

NUTRITION: Energy need The first year; 80-120 kcal/kg/day, decreases

10 kcal/kg/day every three years.

In infants; 9-15% from proteins 45-55% from carbohydrates 35-45% from fats

In older children; 10-15% prt 55-60% ch 30 % fat

Proteins : 4 cal/1 gr prt

Aminoacids+ammonium compounds 24 aa ; 9 are essential for infants (cannot

be synthesized)= treonin, valine, leusine, isoleusine, lysine, tryptophan, phenylalanine, methionine, histidin.

arginine, cystine, and taurine= essential for LBW infants (taurine; improve fat absorbtion in preterm infants)


Dietary protein is hydrolyzed by in the stomach PEPSIN

Pancreatic TRYPSIN digestion in the lumen of small intestine

PEPTIDASE digestion by pancreatic and intestinal peptidases

Nitrogen is absorbed from the gut lumen as A.A.>v.porta>liver>tissues


Liver plays a central role in aa metabolismExcess aas are degraded in the liver

except for the branched chain aas which pass in to the systemic circulation and are taken up primarly by muscle. After removed of the amino group, the ketoacids are either utilized directly for energy or converted to carbohydrate and fat. Nitrogen is excreated primarly via the kidney as UREA.


AA in tissues; albumin

hemoglobine

hormones

All the body’s protein plays a role ;

- in body structure

- function

Because there are no true stores of body protein, a regular dietary intake is neces sary.

LIPIDS; fats are the main dietary energy source for infants.Over 98% of these fats are in the form of

TRIGLYCERIDEs (3fatty acids + gliserol)2% free fatty acids, cholesterol, mono- di

glicerides, phospholipids.Natural fats contain saturated or unsatura-

ted long chain fatty acids with 4-24 carbon atoms.

FATS are required;

For the absorbtion of fat soluble vitaminsFor myelination of CNS,Provides essential fatty acids (EFA)

necessary,For brain development,For phospholipids in cell membranes,For synthesis of prostoglandins and

leukotrienes

LIPIDS

EFA’s are polyunsaturated fatty acids derived from;

LINOLEIC ACID W6 ;1,7% of total cal.LINOLENIC ACID W3 ;0,5% of total cal.Arachidonic acid can be obtained from

linoleic acid and primarily present in membrane phopholipids ( prostoglan_ dines and leukotriens ^^metabolites of arachidonic acid^^ contain W6)

LIPIDS

Linolenic acid is a W3 acid.Controls synthesis of arachidonic acid,

and effective on nerve conduction.Important derivatives of linolenic acid

are;Eicosapentaenoic acid Decosahexaenoic acid = found in human

milk and brain lipid

LIPIDS

Deficiency of EFA(W6) = growth failure, erythematous skin lesions, decreased capillary resistance, increased fragility of erythrocytes, thrombocytopenia, poor wound healing, increased susceptibility to infection

LIPIDS

Deficiency of EFA (W3); dermatitis, neurologic abnormalities (blurred vision, peripheral neuropathy, weakness)

LIPIDS

Digestion; oral lipaseIn the lumen of the gut ;pancreatic

lipase; triglycerides hydrolises to mono-

glycerides, FFA, Gliserol.- Bile salts

LIPIDS

Pancreatic lipase and bile salt levels are low in early postnatal life.

Bile salts have a major role in emulsi-fication of FA allowing their passage through the unstirred water layer to the surface of the mucosal cell.

LIPIDS

After passage into the enterocyte LONG CHAIN (≥ C12) FAs and monoglycerides are reesterified to monoglycerides to triglycerides and are packaged with phospholipids, cholesterol and protein into chylomicrons which are transported in the lymphatics to the systemic circulation.

LIPIDS

At the capillary endothelial surface in adipose and muscle tissue, LPL hydrolyzes triglycerides from chylomicrons releasing FFA and glycerol which are taken up by the adjacent cells. LPL also hydrolyzes triglycerides synthesized in the liver and transported to peripheral tissues as very low density lipoproteins. (VLDL)

LIPIDS

ß-oxidation of FA takes place in mitochondria of muscle and liver. CAR- NITINE is necessary for oxidation of FAs. (carnitine is synthesized in human liver & kidney)

In the liver substantial quantities of FA s are converted to ketone bodies==> released in to the circulation and provide an important source of fuel for the brain in the young infant

LIPIDS

MCT are much more readily absorbed than LCT and are then transported directly to the liver via portal circulation. They are rapidly metabolized in the liver, don’t require carnitine to enter mitochondria. Useful in luminal phase defects (cirrhosis), absorbtive defects (short bowel syndrome, chronic inflammatory bowel disease)

LIPIDS; energy density of

1gr SCFAS 5,3 kcal1gr MCFAS 8,3 kcal1gr LCFAS 9 kcal

CARBOHYDRATES

The energy density of CH is 4 kcal/gram stored as glycogen in liver and muscle.

Monosaccaride: glu, gal, fruDisaccaride: lac, suc, mal in diet.Polysaccaride: starchStarch (amilase) ________ >

disaccarides and oligosaccarides = > hydrolized into glu, gal, fru.

Carbohydrate digestion

Oral and pancreatic amilase (starch)Disaccaridase (disaccarides) at

microvilliAbsorb from the intestinal mucosal

cells.

CARBOHYRATES

Maltose: glu + gluLactose: glu + galSucrose: glu + fru ; at the base of the

villi. Glu and gal are absorbed actively with

Na.Glu is the principal fuel for the brain and

necessary energy source for certain other tissues including red and white blood cells.

MAJOR MINERALS

CALCIUM: More than 99% in the skeleton.

55% is ionized in blood plays a role in neuronal exitability, contraction of muscles. # regulation of enzyme activities # coagulation formation

# Ag-Ab interaction.

MAJOR MINERALS

Control of Ca absorbtion = 1,25 DHC, PTH, Calsitonin

Plasma level : 9-11 mg %Dietary sources: milk and products,

green leafy vegetables, fortified cereals egg yolk.

MAJOR MINERALS

PHOSPHORUS: More than 85% of body P in bone. P is a component of many organic compounds that have a vital role in metabolism including ATP & 2,3 DPG. The other compounds containing P include cell membrane phospholipids and nucleotides. ~ 80% of dietary phophorus is absorbed; the kidney is responsible for homeostatic control. PTH decreases tubular reabsorbtion of P. Plasma levels 3-4,5 mg/dl (4-7 mg/dl in children)

Sources:milk, cheese, egg yolk, meat, cereal,green leafy vegetables.

MAJOR MINERALS

MAGNESIUM: 50% is in bone. 25% is in muscles. Intracelular.Activates many enzymes => P hydrolyzing and transfer- ring enzymes involved in energy metabolism.Plays major role in nucleic acid metabolism. Plays a role in neuromusculer exitability. Plasma level ; 1,5-2 mEq/L.

Sources: soya been, cereal, green leafy vegetables.

MAJOR MINERALS

SODIUM : 125-145 mEq/L.Extracellular mineralOsmotic and acid-base regulationAbsorbed from intestineExcreated via, urine sweet and stool

MAJOR MINERALS

POTASSIUM: 3,5-4,5 mEq/L.Intracelular mineral.Muscle contraction.In acidosis intracelular K+ is changed

for H+=> K+ is shifted into the extracellular fluid and is lost in urine=> total body K is depleted.

MAJOR MINERALS

CHLORIDE: Extracellular mineral.Osmotic and acid-base regulation. Active

Cl transport in ascending loop of Henle in necessary for passive reabsorbtion of Na+.

TRACE ELEMENTS :

Iron, iodine, zinc, copper, selenium, manganese, molibdenium, chromium, cobalt, fluoride.

Dietary sources: Human milk, meat, shellfish, nut, cereals.

The breastfed infants doesn’t require other sources of trace elements including iron for the first 4-6 months.

Infants feed cow’s milk are at risk for deficiencies of iron and copper.

MAJOR MINERALS

Iron: component of Hb, myoglobin, cytocroms; for oxygen transport.

Zinc: component of many enzymes in nucleic acid metabolism, protein synthesis.

Copper: component of several oxidative enzymes.

Selenium: essential component of glutat-hione peroxidase which catalyzes the reduction of hydrogenperoxide to water.

VITAMINS

FAT SOLUBLE :A,D,E,K.WATER SOLUBLE: B1,B6, B12, folic

acid, C vit, niacin, pantothenic acid, biotin, carnitine.

FAT SOLUBLE VITAMINS

Deficiency in those vitamins develop more slowly because the the body accumulates stores of fat soluble vitamins. Excessive intakes carry a considerable potential for toxicity.

Vit A : A critical role in photochemical basis of vision, modifies differentiation and proliferation of epithelial cells. (resp syt). Necessary for glycoprotein synthesis and for integrity of the immune system.


Precursor, ß-carotene => 2 mol A vit

Serum level : 20-50 microgr/dl

Suggested intake/ day: 200U/ 100kcal

Active Vit A

retinol retinal retinoic acid retinil ester


Deficiency : Night blindness, xerosis (dryness of cornea and conjuctiva), xerophtalmia (extreme dryness of con- junctiva), Bitot spots, ulceration and perforation of cornea, follicular hyperke- ratosis, pruritis, growth retardation, anemia, hepatosplenomegaly, susceptibility to infection.


Toxicity (20,000 IU/day) vomiting, increased intracranial pressure, irritability, headache, emotional lability, arthralgia, abdominal pain.

Diatary sources: egg, liver, meat, fish oil, corn.


Vit D: regulates Ca, P metabolism. Stimulates the intestinal absorbtion of Ca,P.Renal absorbtion of filtered Ca. Mobilization of Ca and P from bone.

DHC in the skin--> cholecalciferol (D3) (UV 296-310 μ)

Ergosterol ---> ergocalciferol (D2) (radiation)


Absorbed Vit D (in chylomicrons)--> liver (undergo 25-OH)= calcidiol

Kidney (1-OH) = active vit D 1.25 dihydroxycholecalciferol, calsitirol

Suggested intake /day = 400 IU ( 800 IU for preterms)

30 min/wk total body2 hr/wk head sun exposure


Deficiency: osteomalacia (adults) , rickets (children)

Toxicity: hypercalcemia, vomiting, consti- pation, nephrocalsinosis.

Dietary source: vit D fortified milk, formulas, egg yolk, fish.


VITAMIN E: stops oxidant reactions (antioxidant) cell membrane stabilization, modulate genetic expression, platelet aggregation

Deficiency: hemolytic anemia, neurologic disoreder, abnormalities in eye movements, weakness, degeneration of retina.

Toxicity: necrotising enterocolitis.


VITAMIN K: K1 is obtained from leafy vegetables, soybean oil, seeds, cow milk.

K2 = 60% of the activity of K1 is synthesized by intestinal bacteria.

Necessary for the maintenance of normal plasma level of coagulation factors II, VII, IX, X

Necessary for maintenance of normal levels of anticoagulation protein c.


Vit K deficiency occurs in newborns especially those who are breast fed and who do not receive vit K prophylaxis at delivery = hemorrhagic disease of newborn.

Later vit K deficiancy occurs = fat malabsorbtion syndromes, use of nonab- sorbed antibiotics, use of anticoagulant drugs (warpharine)

Hemorrhage into the skin ,GIS, GUS, gingiva, lungs, joints, CNS

Toxicity; vomiting, hemolytic anemia, hyperbi- lirubinemia.

WATER SOLUBLE VITAMINS

Danger of toxicity is not great because excesses of these vitamins can be excreated in the urine.

Deficiencies develop more quickly because of limited stores.

Vit B : B1(Thiamin) B2 (Riboflavin), Niacin, B6 (Pridoxine), Pantothenic acid, Folic acid, B12 (Cobalamin), Biotin

Coenzyme in carbohydrate, protein and fat metabolism


B12- Folic acid ; formation of erythro-cytes

B1; whole grain, cereals. Def; infantile beriberi (cardiac, aphonic, pseudo-meningitic) (seen in infants breastfed by mothers with history alcoholism or poor diet, complication of TPN, PEM or prematurity


B2 : Meat, wheat, leafy vegetables. Def: chelitis, angular stomatitis, glossitis, B6 All foods Def: irritability, seizure, GI disturbance,

anemia, glossitis, cheliosis, (prematurity, drug {INH})

NİACİN:meat, fish, wheat. Def: pellagra, (weakness, dermatitis, diarrhea,

dementia) (prematurity, maize- millet diets – high leucine low triptophan)


Pantothenic acid : ubiquitousDef: weakness, GI disturbance, burning

feetBiotin : yeast, liver, kidneys, nuts, egg

yolksDef: dermatitis, alopecia, irritability,

lethargy. (supressed intestinal flora and impaired intestinal absorbtion)


Folic acid : leafy vegetables, fruits, whole grains, orange juice, beans, nuts.

Def: megaloblastic anemia, neutropenia, thrombocytopenia, growth retardation, delayed maturation of CNS in infants, glossitis, jaundice, mild splenomegaly, neural tube defects.(prematurity, fed with cow’s milk, goat’s milk, PEM, malabsorbtion syndromes, cirrhosis, infections.


B12 : Eggs, liver, meat.Def: megaloblastic anemia, neurologic

degeneration (congenital malabsorbtion syndromes, strict vegeterian diet, breastfed infants of mother latent pernicious anemia)

Vitamin C: Strong reducing agent.Collagen synthesisCholesterol= bile acids, steroid

hormones


Leukocyte function Interferon production Carnitine synthesis Fresh fruits, vegetables Def: anorexia, irritability, apathy, pallor, fever,

tachycardia, failure to thrive, increased susceptability to infections, hemorrhagen under skin, long bone tenderness, costacondral beading

(prematurity, lack of fresh fruit and vegetables, maternal megadose during pregnancy= def in infants)


CARNITINE: Transfer of long chain FA from cytosol to mitochondria ( necessary for β- oxidation)

Def: increased serum TGs and FFA, decreased ketones, hypoglycemia, prog- resive muscle weakness or cardiomyopathy (dialysis, inheredited deficits of carnitine synthesis, organic acidemia, valproic acid.)

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NUTRITION. The nutrient requirements of the child are influenced by; Body composition, the rate of growth Composition of new growth Vary with the child’s