Nutrition Flashcards
What is the difference between SGA vs IUGR?
SGA - BW <10% ile, can be constitutional and NOT NECESSARILY PATHOLOGIC
IUGR - fetus has not reached its growth potential due to pathological factors (ex: suboptimal in utero- placental environment, genetic factors (fetus) or maternal factors
Difference between whey and casein?
Whey has greater cysteine and less methionine than casein
Both are major protein sources in neonates
What are whey to casein ratios in Colostrum? Mature milk? Casein based formulas? Whey based formulas? Preterm milk?
Whey:Casein
Colostrum 80:20
Mature milk 55:45
Casein based formulas 20:80
Whey based formulas 60:40
Whey is the liquid portion after the milk curdles - that is why BF babies poop after every feed (faster transit time due to whey)
Cysteine is a substrate for glutathione (higher with whey)
Curdles is casein (Lower solubility at pH 4.6)
Preterm milk 60:40
Who is at risk for Vit B12 deficiency?
Folate deficiency?
Risk of Vitamin B12 deficiency in breast-fed infants of vegetarian mothers who do not ingest eggs or dairy products
- anemia
- associated with methylmalonic acidemia and homocystinuria
Risk of folic acid deficiency in infants fed only evaporated milk or goat’s milk
- poor weight gain, anemia;
- often coexists with iron deficiency
Risk for pyloric stenosis (PS) ?
If Mother has PS - 19% if boy, 7% if girl
If Father has PS - 5.5% if boy, 2.4% if girl
Sibling has PS - 4% if boy, 2.4% if girl
What are the fetal energy sources?
2/3 Maternal glucose (facilitated diffusion)
1/4 Placental lactate
Rest: Maternal amino acids (active transport)
How does TBW, ECF, ICF Na and Chloride content change w increasing GA?
TBW ECF Na and Cl decrease ICF increases (so does protein, fat, iron, Ca, Ph)
Name the Essential amino acids?
PVT TIM HALL
Phenylalanine
Valine
Threonine
Tyrosine
Isoleucine
Methionine
Histidine
Arginine (only if + nitrogen balance)
Leucine
Lysine
Which are critical fatty acids transferred across placenta to fetus?
Arachadonic acid and docosahexanoic acid (DHA)
Increases in 3rd trimester
Biomagnification-higher values in cord blood then maternal circulation
Critical for brain and eye development
Name the 2 essential fatty acids?
Linoleic and alpha linolenic acid
Which are the 2 most prevalent fatty acids in human milk?
Oleic
Palmitic acid
How long does it take to develop essential fatty acid deficiency?
Short delay of 3-7 days without providing linoleic and alpha linolenic acid
Neonate with scaly dermatitis, alopecia, thrombocytopenia and FTT. Dx?
Essential fatty acid deficiency
Diagnostic test:
Triene:tetraene ration>0.2 (might also describe as increase mead acid (triene) and decreased arachadonic acid (tetraenoic)
Can be prevented w as little as 0.5-1g/kg/day of intralipid
For a positive nitrogen balance how many grams of glucose must be provided per gram of protein?
6g glucose for 1g of protein
Carbs should provide 35-65% total cals
Fats 30-50%
Protein 7-15%
Tissue richest in long chain PUFAs?
Retina
Long chain polyunsaturated fatty acids are needed in the development of _____.
Brain
Neural tissue
Eyes
*specifically AA (arachidonic acid) and DHA
Which trace element in excess amount can cause neurotoxicity?
Manganese-deposition in basal ganglia leading to injury
Copper causes cirrhosis of liver
Chromium-renal failure
Zinc-decrease leukocyte and phagocyte activity
Which amino acid is needed for synthesis of glutathione?
Cysteine
What form of Vit D reflects a baby’s Vit D levels?
25 hydroxyvitamin D
Due to it’s longer half life
Folates are responsible for degradation of which amino acids
Homocysteine
Histidine
Folate is responsible for the synthesis of ________.
Purines
Pyrimidines
AA (serine and methionine)
Which GA is the highest growth rate?
32-36 weeks (peaks 31g/day)
What are the hormonal factors that affect growth?
Increase in GH and placental lactogen
Increase in glucose and lipid concentrations to stimulate fetal insulin production, fetal growth, adipose tissue, and restricts protein degradation
PL appears to be mediated by insulin-like growth factors
Estimated fetal energy expenditure?
35-55kcal/kg/day
Source Maternal glucose (2/3)-facilitated Placental lactate (1/4) Maternal AA (rest)-active
Which AA are glucose precursors?
Alanine
Glutamic acid
Aspartic acid
What are neonatal caloric requirements?
120-150 kcal/kg/d
To allow energy expenditure and growth
Which pancreatic proteases are decreased in PT and term babies
Trypsin’s and chymotrypsin
Describe fat digestion
(1) bile acid emulsification of fat globules (form micelles)
(2) triglyceride hydrolysis by lipase
(3) fatty acid transfer across intestinal mucosa
PT and FT infants have decreased bile acids and pancreatic lipases
Which FA are absorbed directly into blood? How is total fat absorption not affected?
• Short and Medium-chain fatty acids are absorbed directly into the blood via intestinal capillaries and travel through the portal vein.
Bile acids are not needed
for short or medium chain fatty acid processing.
• Despite reduced bile acids and pancreatic lipase, total fat malabsorption is
minimized:
• Lingual lipase, gastric lipase
• Lipase in breast milk
Carbohydrate Metabolism in Neonate
Salivary & Pancreatic Amylase
hydrolyzes starch, glycogen, and
dextrin to glucose, maltose, and
limit-dextrins: decreased secretion in newborn
Glucosidases (lactase, sucrase,
maltase, isomaltase) adult levels at 28 weeks*
Lactase adult levels at 36 weeks
Glucose transport across epithelium less efficient in newborn, especially
PT
Colonic salvage pathway: microflora
ferments non-absorbed nutrients to energy-rich products that are
ahsorhed hv the colon
Composition of human milk
Fat globules cholesterol and Phospholipids
Micelles
Cells
Aqueous phase
Which is the primary carbohydrate in human milk?
Lactose
Human milk oligosacharides
Protein delivers 75% nitrogen
Fat provides 50% of calories
What makes up mother’s milk?
• Lactose is primary carbohydrate
Protein delivers 75% of nitrogen
Fat provides 50% of calories
