Pediatric Nutrition I Nutrition of Neonates and Infants

1
Pediatric Nutrition I

• Nutrition of Neonates and Infants
• Prior to 1 year of age
• Growth Rates and Nutritional Goals
• Nutrient Requirements
• Energy, Protein, Minerals, Vitamins
• Absorptive/Digestive Immaturity
• Human Milk
• Infant Formulas

2
Neonatal Growth and Nutrition

• Growth rates are most rapid in the first six
  months of human life
• Nutrient requirements on a weight basis are
  highest during the first six months
• Rapid organ growth and development occurs during
  the last trimester and first six months
• The detrimental effects of nutritional
  insufficiencies are magnified during periods of
  rapid organ growth (I.e., vulnerable periods for
  brain growth)

3
Infancy Nutritional Goals

• Provide sufficient macro- and micronutrient
  delivery to promote normal growth rate and body
  composition, as assessed by curves which are
  generated from the population
• Curves exist for
• Standard anthropometrics weight, length, OFC
• Special anthropometrics arm circumference,
  skinfold thickness
• Body proportionality weight/length, mid-arm
  circumference head circumference ratio
• Body composition measurements (e.g. DEXA, PeaPod)
  are not standardized yet

4
Growth
Curves
for
Infants
GIRLS Birth to 36 mo
5
Growth
Curves
for
Infants
BOYS Birth to 36 mo
6
Infancy Energy Requirements

• Term infants require 85-90 Kcal/kg/d if
  breast-fed, 100-105 Kcal//kg/d if formula
• Differences are due to increased digestibility
  and absorbability of breast milk
• Presence of compensatory enzymes (lipases)

7
Infancy Energy Requirements

• (Continued)
• Energy requirements are 20 higher in premature
  infants due to
• Higher basal metabolic rate
• Lower coefficient of absorption for fat and
  carbohydrates
• Energy requirements decrease to 75 Kcal/kg/d
  between 5-12 months

8
Partitioning of the Energy Requirements During
Infancy
Basal Metabolism
Gross Energy Intake
Metabolizable Energy Intake
Thermic Effect of Feeding
Activity
Energy Stored growth
Tissue Synthesis
Energy Excretion
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Infancy Energy Requirements in Disease

• Diseases of infancy that increase BMR (cardiac,
  neurologic, respiratory) affect energy
  requirements
• Diseases that increase nutrient losses
  (malabsorption due to cystic fibrosis, celiac
  disease, short bowel syndrome) increase the need
  for energy delivery, although the BMR is normal

10
Infancy Protein Requirements

• Late gestation and infancy is the time of highest
  protein accretion in human life
• Protein requirements range from 1.5 g/kg/d
  (healthy breast-fed infant) to 3.5 g/kg/d
  (septic, preterm infant)
• Amino acid synthesis is incomplete in the
  premature taurine and cysteine are additional
  essential amino acids because of immaturity of
  enzyme systems

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Rates of Whole Body Protein Synthesis During
Growth

• Preterm infants 15 g/kg/d
• Toddlers 6 g/kg/d
• Adolescents 4 g/kg/d

12
Infancy Minerals, Trace Elements

• Nutrient Term Preterm 5-12
  Month
• Neonate Neonate Infant
• Na (mEq/kg/d) 2 - 3 4 - 7 1 - 2
• K (mEq/kg/d) 1 - 2 2 - 4
  1 - 2
• Ca (mEq/kg/d) 60 150
  40
• Iron (mEq/kg/d) 1 2 - 4 0.7
• Zinc (mEq/kg/d) 0.2 - 0.5 0.4
  0.3

13
Infancy Vitamins

• Water-soluble vitamins (B, C, folate, etc.) are
  rarely a problem in newborns and infants babies
  are born with adequate stores and/or all food
  sources have adequate amounts
• Fat-soluble vitamins (A,E,D,K) may present
  significant problems because of relatively poor
  fat absorption by newborn infants (especially
  premature infants)

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Infancy Fat-Soluble Vitamins

• K Needs to be given at birth to prevent
  hemorrhagic disease of newborn adequate
  thereafter due to synthesis by intestinal
  bacteria
• D Low amounts in breast milk infants born in
  winter in north and infants who are clothed at
  all times (minimal sun exposure) have been
  identified with rickets
• AAP now recommends 400 IU/d for all infants

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Infancy Fat-Soluble Vitamins

• (Continued)
• A Essential for normal structural collagen
  synthesis and retinal development deficiency in
  premature infants contribute to fibrotic chronic
  lung disease
• E Antioxidant that protects against
  peroxidation of lipid membranes preterms have
  poor antioxidant defense and are subjected to
  large amounts of oxidant stress vitamin E
  deficiency causes severe hemolytic anemia

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Infancy Limitations to Nutrient Accretion

• Rapid transit time
• Immature digestive capabilities
• Reduced nutrient retention

17
Infancy Immature Digestion of CHO

• Primary sources of CHO in newborn and infant diet
  are disaccharides (esp. lactose)
• Disaccharides must be broken into component
  monosaccharides to be absorbed
• Lactose glucose galactose (lactase)
• Sucrose glucose fructose (sucrase)
• Maltose glucose glucose (maltase)

18
Infancy Immature Digestion of CHO

• Intestinal lactase concentrations are low at
  birth and are not inducible
• Amylase, necessary for breaking down starches,
  are not adequate until gt 4 months

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Weeks of Gestation
Sucrase, Maltase, Isomaltase Glucose Uptake
10 Wks
Salivary Amylase Zymogen Granules in Pancreas
20 Wks
Pancreatic Amylase
22 Wks
24 Wks
Lactose
24 - 28 Wks
Gluco-amylase
20
Infancy Proten Digestion

• 85 of ingested protein is absorbed in spite of
  functional immaturities
• Reduces stomach acidity
• Low pancreatic peptides levels (chymotrypsin
  caroboxypeptidases)
• Compensation is by trypsin and brush border
  peptidases

21
Infancy Percent of Dietary Fat Absorbed

• Adult 95
• Term infant 85-95
• Preterm infant 50 - 90 (dependent on source of
  fat)

22
Infancy Etiology of Fat Malabsorption

• Low levels of intestinal lipases
• Small bile salt pool

23
Infancy Breast Milk As a Food Source

• Committee on Nutrition of the AAP strongly
  recommends breastfeeding for infants
• The rates of breastfeeding have risen recently,
  but the attrition rate is high

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Infancy Breast Milk As a Food Source
(Continued)

• The goal of the AAP and NIH Health People 2010 is
  to have 75 women breastfeed, with a continuation
  rate of 50 at 6 months
• It is necessary to breastfeed for at least 12
  weeks to achieve the immunologic and disease
  preventative benefits of breast milk
• Physicians role is to support, counsel and
  trouble-shoot

25
Advantages of Human Milk

• Health
• Nutritional
• Immunologic
• Neurodevelopmental
• Economic
• Environmental

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Advantages Health

• Studies in developed countries
• Reduced prevalence of
• Diarrhea
• Otitis media
• Lower respiratory infection
• UTI
• NEC (in preterms)
• SIDS

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Advantages Health

• Protection of infant from chronic diseases
• Insulin dependent diabetes mellitus
• (OR 0.61)
• Inflammatory bowel disease
• Allergic disease
• Childhood lymphoma (OR 0.91)
• Obesity (OR 0.75-0.87)

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Advantages Health

• Protection of mother from
• Pregnancy
• Postpartum hemorrhage
• Bone demineralization
• Ovarian cancer

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Advantages Nutritional

• Complete human nutrition for 6 months
• Iron at 4 months
• Vitamin D in northern climates, covered infants
  and mothers, vegetarians (vegans)
• Energy is more accessible than from formula
• Compensatory lipases ? better fat retention
• But, BF babies grow slower too

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Advantages Nutritional

• Amino acid spectrum matches infant need lower
  protein and solute load
• Faster gastric emptying ? less reflux

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Advantages Neurodevelopment

• Better visual acuity (early)
• Role of DHA?
• Higher IQ (debatable)
• Independent of nursing
• Components in human milk which may potentiate
  the effect
• DHA
• Growth factors

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Advantages Protection from Obesity

• 25 reduced risk of obesity if BF
• Adjusted OR 0.75-0.89
• Dose response (Koletzko et al)
• Rate of Adolescent Obesity
• 12 if BF lt 1month
• 2 if BF 12 months
• Small effect compared to OR if parents are
  obese (4.2), low physical activity (3.5) or TV
  (1.5)

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Advantages Personal Economics

• Reduced cost of feeding
• No formula cost (-855/year)
• Increased maternal consumption (lt400)
• Net savings of gt400/child
• Reduced health care costs due to
• Lower incidence of childhood illness
• Reduced income loss due to
• Less days lost to cover childhood illness

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Contraindications

• Galactosemia in infant
• Illicit drug use by mother
• Certain maternal infectious diseases
• Active TB
• HIV (US only)
• Not CMV
• Certain maternal medications
• Anti-neoplastics, isotopes, etc
• How about SSRI's?

35
Infancy Infant Formula

• Promotes adequate growth, but not brain and
  immunologic development compared to human milk
• New formulas contain LC-PUFAs
• Soon to be added prebiotics probiotics
• Most are cow-milk based, although soy-protein
  based and fully elemental formulas are available

36
Infancy Infant Formula

• (Continued)
• Cows milk (not formula) is contraindicated in
  the first year of life
• High solute load can lead to azotemia
• Inadequate vitamin D and A
• Milk fat poorly tolerated
• Low in calcium can lead to neonatal seizures
• Gastrointestinal blood loss/sensitization to
  cow- milk protein

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Summary

• Feed humans human milk
• It is species specific
• If not human milk, CMF or Soy formulas with iron
  are indicated
• Hypoallergenic formulas are highly specialized,
  expensive and overused