infant formua products

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Transcript infant formua products

• Human milk is most physiologically suited
to infants
• Optimal source for feeding infants till 12
• Human milk is the only source of nutrition
till 6 months of life.
• For infants whose mother cannot or will not
breast feed them, alternatives are needed
Infant Formula Products: Introduction
Infant physiology and growth: GI and renal systems
GI maturation
Second trimester of pregnancy: all segments of GIT are
Third trimester; maximal GI growth and differentiation.
Preterm infants (before 32 weeks of gestation)
Transition from intrauterine to extra uterine feeding
requires maturation of many physiologic processes,
Nutritive sucking: 33-34 weeks of gestation. No
problem in term infants, but in premature,,,,,
Preterm (before 34 weeks) cannot coordinate sucking,
swallowing and breathing
Definition of Premature Birth
 The WHO and AAP define premature birth as the
delivery of an infant before 37 weeks of gestation.
A full term infant: 37-42 weeks of gestation
 The NCHS of the CDC generally reports data
on three categories of preterm birth:
1. Overall preterm, less than 37 weeks
2. Moderately preterm, 32 and 36 weeks
3. Very preterm births, less than 32 weeks
• Early infancy:
- Liquid nutrition only: poor coordination of
complex tongue movements and swallowing
- Frequent feeding: limited stomach capacity:
20-90 ml at birth, 90-150 ml at 1 month
- Term infants: gastric and pepsin secretion
peaks at 10 days, in preterm basal acid
output is low
- Milk in the stomach increases pH, poor
pepsin activity
- CHO digestion: lactase, sucrase, maltase,
isomaltase, glucoamylase are mature.
Lactase activity may be immature in
premature infants.
- Pancreatic amylase is low in full term
infants, till 1 year of life. Salivary amylase
may compensate for that
- Low pancreatic lipase concentration, bile salt
synthesis is low, lingual and gastric lipases
- Protein digestion and absorption are mature
• Kidney maturation:
Ability of the kidney to excrete solute load
Glomerular filtration starts in the 9th week of
fetal life
GFR increases after birth and reaches adult
level at age of 3
-Average birth weight: 3.5 Kg
-Premature infants: LBW: less than 2500 gm
-VLBW: less than 1500 gm
-6-10% weight loss after birth
-Weight gain: 20-25gm daily till 4th month, 12gm/day
for the coming 8 months
- Double the weight by 4 months and triple by 12
-Changes in body composition occurs as well: at
birth, total boy water is 70% and decreases to 60%
at 1 year. Adipose tissue increases
Normal values are expressed as percentiles: see
growth charts
Introduction, cont.
Nutritional standards
- Acceptable growth needs a balance between adequate intake:
absorption and utilization of energy.
- Recommended Dietary Allowance (RDA), energy requirements
- Components of a healthy infant diet
1. Fluid:100ml/kg per day for the first 10 kg + 50ml/kg for each
additional kg. Water intake in the first 6 months is derived from
breast milk or formula
2. CHO: 40-50% of total calories. Should be balanced with fat intake
to allow better development.
Lactose is the primary source.
Lactose intolerance: lactase deficiency
Congenital lactase deficiency is rare
Secondary lactase deficiency: in some cases of gastroenteritis
Introduction, cont.
3. Protein and amino acids: 2.2gm/kg/day (birth-6 months),
1.6gm/kg/day (6-12 months)
-Essential a.a.: isoleucine, leucine, lysine, methionine,
phenylalanine, threonine, tryptophan, valine
-Conditionally essential a.a.:cystein, taurine, tyrosine, histidine
4. Fat and essential fatty acids
-Most dense source of calories in the diet
-Supplies 40-50% of the energy intake of infants
- Essential PUFA: Linoliec acid, linolenic acid: precursors for LCPUFA:
5. Micronutrients
-Biotin, choline, inositol
-Minerals: calcium, phosphorous, Iron, zinc, copper, manganese
Milk production
Lactating mammary gland:
 Branching network of ducts formed of epithelial cells ending in
extensive lobulo alveolar clusters that are the site of milk secretion
 Alveoli are surrounded by myoepithelial cells that function in milk
ejection, and a vascularized connective tissue containing adipocytes
and fibroblasts
 Ejection of milk requires contraction of the myoepithelial cells
stimulated by oxytocin
Lactating alveolar cell: highly active secretory cell
- numerous mitochondria
- Extensive rough endoplasmic reticulum
- Well developed Golgi apparatus
- Epithelium is connected by tight junctions
- Basal side contacts myoepithelial cells and the basement mem