Midterm 2.docx

Midterm 2 Chapter 4: Pregnancy Normal physiological changes of pregnancy Increase of 7-10 l of body water: building blood and tissues during 1st trimester Increase plasma volume: 1st week until 34th week with steepest increase during 2nd trimester directly related to fetal size Increase blood volume...

Midterm 2 Chapter 4: Pregnancy Normal physiological changes of pregnancy Increase of 7-10 l of body water: building blood and tissues during 1st trimester Increase plasma volume: 1st week until 34th week with steepest increase during 2nd trimester directly related to fetal size Increase blood volume: hemodilution Increase RBC mass directly related to fetal size Altered stomach function: decrease in GI motility and increase absorption of nutrient Cardiac function: heart rate increases by 20% (cardiac hypertrophy) and increase CO Renal function: increase GFR and decrease tubular reabsorption increase excretion of fetal waste, glucose, folate, iodine, amino acid Pulmonary function: increase ventilation due to increase O2 demands increase BMR Plasma lipid profiles: increase plasma lipids to conserve glucose blood glucose decreases in 3rd trimester, but increase lipolysis and mild ketosis Appetite and thirst Hepatic gluconeogenesis: decrease alanine bioavailability since less muscle breakdown + increase placental uptake Curvature of spine Fat stores increase Uterus expands Hormones promoting growth and changes in breast tissue Smell and taste: impact dietary behavior, associated with natural changes in hormones Nausea and vomiting: 6th to 12th week because increase in estrogen and hCG Positive predictor of pregnancy outcome and decrease risk of fetal death Avoid foods that triggers it Edema common since expanded blood volume Weight gain recommendation Based on pre-pregnancy BMI: lower BMI = higher weight gain recommended vs high BMI = lower weight gain recommended Need 22% of body weight as fat + obligatory weight gain (protein stores) for fetal, placental tissues, enlarged uterine and breast tissue, expanded blood volume, maternal tissue accretion, extracellular fluid, fat stores, and amniotic fluid: 40% of energy needed to support pregnancy deposited in 1st 20 weeks, and average of 3.8 kg of fat (increase subcutaneous fat) laid down by 30th week Fat storage increase more during 1st several weeks of 2nd trimester and decreases later Body fat = reserve of 30k calories for pregnancy and lactation Average weight distribution: breast size < uterus and muscle < blood and fluids < maternal fat stores < fetus and placenta 1st 10 weeks: 3-4 lbs Rest: 1 lb/week Recommendations: 5-6 small meals/day, snacks, max 3-4 hours without eating, healthy fats Pregnancy complications High gains in fluid: weight gain and edema Insufficient fluid: constipation, common especially in 3rd trimester due to relaxed musculature of GI tract (normal changes, decrease maternal activity, iron supplements) Treatment: increase fiber & fluid intake, physical activity, bulk forming agents, probiotic supplements laxatives not recommended because dehydration + nutrient deficiencies Relaxed cardiac sphincter due to increase estrogen and progesterone, or by pression from uterus and fetus: heartburn Avoid foods that triggers it Gastroesophageal reflux disease (GERD): more severe form of heartburn caused by fluctuating hormones on lower esophageal sphincter Triggers: eating before bed, intake of fatty/spicy foods, caffeine, mints, chocolate, side effects of medication Skipping too many meals because of nausea and vomiting: ketosis and hypoglycemia teratogenic risk Small frequent high fat, low bulk meals recommended If gaining >1 lb/week when >10 weeks: risk of excessive edema, preeclampsia, stillbirth, placental abruption, decrease blood flow to placenta LBW If <20 lbs weight gain: risk of premature or small for gestational age (SGA) Insufficient blood volume expansion: risk of stillbirth, LBW, spontaneous abortion Entering pregnancy underweight: risk of maternal bone and muscle loss, vitamin and mineral deficiencies, anemia, fatigue, preterm delivery, intrauterine growth restriction (IUGR), LBW Focus on balanced diet, listening to hunger and fullness cues, regular physical activities Entering pregnancy overweight: risk of exercise weight gain during pregnancy gestational diabetes (GDM), HTN, preeclampsia, dyslipidemia, C-section, less likely to start and sustain breastfeeding, CVD risk for baby + mother Children of obese mom: risk of fetal death, congenital malformation, perinatal complications Weight loss not recommended during pregnancy, just less weight gain than someone with normal weight Intervention to prevent excess weight gain: educate about nutrition, increase physical activity, improve diet GDM: glucose intolerance during 2nd or 3rd trimester, resolves after childbirth Increase risk of TDM later and to have it in other pregnancies, C-section, macrosomia, neonatal hypoglycemia Increase risk of obesity Prevention with diet and exercise to maintain blood glucose to minimize risks Medication: insulin, self-monitoring blood glucose mandatory HTN: prevents placenta from getting enough blood LBW DASH to prevent: fruits and vegetables, whole grains, fat-free/low fat, limits saturated fats Classification: chronic if <20 weeks, gestational if 2nd or 3rd trimester, preeclampsia >20 weeks Preeclampsia: high BP and protein in urine after 20 weeks DASH recommended Tx: delivery because leads to complications for mother and baby Anxiety and depression: increase risk of emotional problems, symptoms of ADHD and impaired cognitive development in child Iron, folate, B12 linked to improve depression and mood disorders nutrient-dense foods and beverages important Depression linked to preeclampsia, birth difficulties, less breastfeeding, and risks of developmental & behavioral issues In child Signs: depressed mood, loss of interest, guilt, low self-worth, disturbed sleep or appetite, low energy, poor concentration Eating disorders: may lead to low weight gain, and higher risk of GDM if overweight Anorexia nervosa amenorrhea Bulimia nervosa risk of dehydration Binge eating disorder Meal plan and patient monitoring essential Pica: cravings for non-nutritive substances iron deficiency anemia, lead poisoning, weight gain, toxicity, low Hb/Hct/plasma zinc Birth weight Determined by duration of gestation and rate of fetal growth Most important determinant: gestational age, maternal weight gain, and preconception weight Mortality rates lowest for infants between 2.5-4 kg high perinatal morbidity and mortality related to LBW If excessive >9 lbs: increase risk of hormonally related cancers Issues involved with LBW Preterm birth causes: genitourinary infection, multiple pregnancies, pregnancy induced HTN, low pre-pregnancy BMI, prior history, strenuous physical labor, smoking Risks of LBW: decrease lung capacity in childhood, increase risk of CVD, TDM, impaired glucose metabolism, high BP, high TG, high insulin, low HDL Premature ≤37 weeks Mildly preterm: 32-36 weeks elevated risk of RDS, infection, mortality Extremely preterm: severe morbidity in infancy and childhood, retinopathy, chronic lung disease, neurocognitive problems IUGR <2 SDs in weight for gestational age, <10th percentile in weight for gestational age, or <2500 g and gestation age>37 weeks Associated with congenital anomalies, low energy intake and pre-pregnancy BMI, short maternal stature, pregnancy induced HTN, smoking, alcohol, malaria (anemia) Hypoglycemia and hypocalcemia in early neonatal period: risk of infection, and if catch-up growth incomplete mild neurocognitive deficits and behavioral problems Associated with adult disease: HTN, T2DM, insulin resistance (obesity + fetal growth deficiency), CHD Abnormal patterns of fetal growth linked to adult disease Normal: S-shaped curve weight maintenance or slight loss normal in 1st trimester, weight gain in 2nd and 3rd trimester Symmetrical small babies of LBW: babies thin at birth, but catch-up later in infancy large head and narrow waist low ponderal index = birth weight/length3 Average birthweight infants, but small in proportion to placenta: grow less than average during infancy Mechanisms of pregnancy undernutrition and adult disease in offspring Undernutrition: increase maternal corticosteroid production increase fetal maturation of lungs and other organs to increase short-term survival Inadequate development of placenta: decrease ability to breakdown corticosteroids, insulin and thyroxine cortisol exposition in early gestation risk of HTN later Improved postnatal nutrition don’t correct metabolic abnormalities in adulthood Exercise recommendations ≥30 mins 5 times/week or total of 150 mins/week of moderate-to-vigorous physical activity to maintain gestational and fetal weight gain decrease HTN disorder and GDM Strength training + aerobic activity + well-balanced diet + hydration + rest Possible contraindications: low-lying placenta, severe anemia, persistent 2nd/3rd trimester bleeding, preeclampsia, pregnancy with >1 baby, previous history of miscarriage Categories for nutritional risk for pregnancy Food insecurity: increase risks of LBW, poor brain development, infection and congenital disabilities Poverty: poorer nutrient intake, smoking Low pre-pregnancy/pregnancy weight Short inter-conception interval: high demands on body stores Chronic illness: TDM, infection, cancer, alcoholism, malabsorption Unusual dietary patterns: pica Poor reproductive history: prior LBW, premature, spontaneous abortion History of anemia or OB: long-term imbalanced diet Adolescent: high nutrient demands, poor financial status/obstetric/nutritional support, drugs and smoking Requirements Energy Increase BEE due to metabolic contribution of uterus and fetus + increase work of heart and lungs increase EER Late pregnancy: ½ of increase in energy expenditure because of fetus Fat free mass (FFM) = strongest predictor of BEE: increase blood volume < skeletal muscle mass < fetal and uterine tissues TEE: steady decrease in PAL (TEE/BEE) as pregnancy advances EER calculation: 1st trimester: same as for nonpregnant active women over 19 years old because weight gain is minor, so no allowance made for energy deposition 2nd and 3rd trimester: takes into consideration gestation and increment for tissue deposition (depends on pre-pregnancy weight higher when underweight, lower when obese) Recommendation unchanged Nutrients Explications AI Fluoride High level of protection against dental caries Sodium Minimum increase needed, so no change No evidence that decreasing it would prevent pregnancy induced HTN/lowers BP Vit K No evidence that usual intakes are inadequate Fiber = dietary + functional fiber Pantothenic acid Biotin Increase biotin metabolism + decrease urinary excretion RDA Phosphorus Intestinal absorption increases of 10% Calcium Maternal skeleton not used as reserve for fetal needs, no changes in maternal bone mass during pregnancy Increase efficiency in intestinal absorption, so no need to increase it even if transfer to fetus especially during 3rd trimester Vitamin E No evidence that maternal supplementation would prevent deficiency symptoms (hemolytic anemia) in premature baby and no reports of deficiency during pregnancy Vitamin D Small quantity of 25(OH)D transferred to fetus Recommendation increased Nutrients Explications AI Chromium Increase weight Manganese Potassium Small increase during pregnancy Water Choline Delivery to fetus through placenta depletes maternal stores Important for embryogenesis and perinatal development Deficiency: homocysteine increased Increase fetal demand for phosphatidylcholine Decreases baby’s circulating cortisol if increased maternal choline during last trimester Fats: w-6 and w-3 For incorporation into placental tissues and fetus important for fetal growth or else LBW Vegetarian could pose risk of brain development since higher arachidonic acid (w-6) and lower DHA (w-3) RDA Molybdenum Increase weight Magnesium Copper Amount accumulated for fetus and products of pregnancy 65-70% bioavailability Selenium Fetal deposition throughout pregnancy to allow accumulation of enough selenium by fetus to saturate its selenoprotein Most highly bioavailable no adjustment made for absorption Iodine Daily thyroid iodine uptake for maternal and fetal tissues Deficiency: miscarriage, stillbirth, birth defects Severe deficiency: cretinism Zinc Higher when 14-18 years old than 19-50 years old Increase zinc requirement during 4th ¼ mean daily Zn accumulation in maternal and embryonic/fetal tissues 27% fractional absorption Iron Same RDA regardless of age vs non-pregnant 14-18 years old lower than 19-50 years old Established using estimates for 3rd trimester to build iron stores during 1st trimester Using upper limit of 25% absorption Factorial modeling for EAR: basal losses + iron deposited in fetus and related tissues + iron in expansion of Hb mass Severe anemia associated with perinatal maternal mortality; moderate anemia associated with risk of maternal death limit expansion of maternal RBC less Hb synthesis, so increase overload of maternal heart to supply oxygen to the fetus Maternal anemia: premature delivery, LBW, increase perinatal infant mortality High [Hb]: associated with SGA, HTN, preeclampsia, decrease plasma volume, increase risk of premature, LBW, fetal death Storage iron can be used, so no supplement recommended if normal stores pre-pregnancy supplement recommended if not enough iron in diet Vitamin A Accumulation in fetal liver (liver has ½ body’s vitamin A when liver stores are low) + requirement increased during last semester 70% efficiency of maternal vitamin A absorbed Vitamin C Lower when 4-18 years old than 19-50 years old To prevent development of scurvy in infants Maternal plasma concentration decreases with pregnancy because of hemodilution + active transfer to fetus more needed Increase requirement if street drugs and cigarettes (x2), heavy alcohol use, regular aspirin use Folate To prevent deficiency in blood concentration and to prevent megaloblastic anemia + decrease risk of NTD Folate actively transferred to fetus: increased concentration in cord blood than maternal blood Inadequate intake: maternal serum and RBC [folate] decrease, megaloblastic marrow changes, and anemia can develop if long-term Primary indicator of adequacy: RBC folate maintenance since it reflects tissue stores Vitamin B12 Maternal absorption becomes more efficient because of increased intrinsic factor B12 receptor + fetal deposition Deficiency in infants 4-6 months if mother strict vegetarian for 3 years Only newly absorbed transported across placenta liver stores not important for fetus Vitamin B6 Significant fetal uptake + maintenance of plasma [pyridoxal P] at non-pregnancy values Increased metabolic needs + weight 75% bioavailability Niacin Increase energy utilization and growth In Nes since can be synthesized from tryptophan Riboflavin Growth in maternal and fetal compartments + increase energy utilization Thiamin Carbohydrates Additional amount required in last trimester Increase energy supply for growth and development of fetus increase metabolic rate increase fuel requirement Increase maternal storage of fat early in pregnancy energy to sustain growth of fetus in last trimester Less fasting maternal blood [glucose] + development of insulin resistance = ketosis Increase glucose utilization by maternal-fetal unit Newborns can utilize ketoacids Protein Maintenance of additional protein stores + support of growth of maternal and fetal tissues (for protein deposition) Changes with trimesters because changes in growth Protein and or/energy deficiency LBW Pre-pregnancy key to prepare for pregnancy demands Chapter 5: Lactation and breastfeeding Immune factors found in milk Anti-infectious agents: Whey protein: resistant against proteolysis/acid because have anti-proteases protecting protein by preserving S-S bonds Antibodies: Bacterial and viral neutralizing capacity inhibits colonization of gut: IgA: B cells from secretory plasma cells in maternal small intestine/respiratory tract where exposed to patho maternal blood mammary gland mature milk Aids in blockage of whole food proteins from absorption by binding them IgA-food protein complex promotes mucus release from goblet cells and proteolysis at mucosal surface Blood IgA binds to food protein to put it out via reticuloendothelial system Antigens pass through leaky junction in GI tract, but colostrum close them IgM IgE: food binds to IgE complex binds FcR on mast cells/basophils cytokines, interleukins and platelet activating factor inflammatory response via histamine IgG: coming from maternal plasma IgI: coming from mammary gland Anti-staphylococcus factor Lysozymes: breakdown proteoglycans Bifidus factor: promotes growth of lactobacilli that secretes organic acids that inhibits pathological bacterial growth Lactoferrin: inhibits siderophilic bacteria that competes for iron because high affinity Lactoperoxidase: kill streptocco and enteric bacteria Lipases: fat breakdown in gut when infection FFA + MAG antiviral Neutrophils: phagocytosis Macrophages: synthesis of complement, lactoferrin, lysozymes, and phagocytosis Complement: opsonization Fibronectin: increase phagocytosis Lymphocytes: synthesize Ig’s B12: binding protein Interferon: inhibits intracellular viral replication Differences between cow’s milk and human breast milk in terms of nutrient content Higher in breastmilk Higher in formula (bovine) Whey Alpha-lactalbumin: binds calcium and zinc Beta-lactoglobulin: can cause allergy responsible for antigenicity of cow’s milk Lactoferrin: immunity, more bioavailable iron Serum albumin: helps with development of mucus IgA: binds to pathogens to prevents entry IgG: associated with colic (crying all the time from pain because of intestinal discomfort) allergy Osteopontin: growth, brain, and immune system development NPN: amino acid, peptide, N-acetyl sugars, urea, nucleotides Milk Whey:casein Nucleotides Xanthine oxidase: binds iron and molybdenum Proteases, lipases, amylases Polyamines, nucleotides: growth factor in human gut Amino acid composition of human milk: Rich in taurine: bile acid conjugation, putative neurotransmitter, conditionally essential amino acid Lower methionine and higher cysteine: cystathioniase late to develop cysteine utilized without need for methionine metabolism (if higher met, may affect CNS) Lower phenylalanine and tyrosine: enzymes late to develop (if higher, may affect CNS) Fat composition: Colostrum: increase proportion of C20 and C22 PUFA Mature milk: increase proportion of C8, C10, C12, C14, C16:1 and C18:2, less nerve cell division, and increase myelination Nutritional advantages and disadvantages of human breast milk Advantages Higher proportion of palmitate at 2-position of TG vs 1-position in formula Better lipolytic activity: LPL, bile salt stimulated lipases, pancreatic-like lipases More oleic acid, and less SFA since oleic is more absorbed More EFA and its precursors: necessary to develop elongase and desaturase Lower in linoleic acid than in formula More LCFA Higher DHA and AA Lactose: aids in mineral absorption by forming soluble chelates and stimulates beneficial gut bacteria such as lactobacilli IgE and IgA protects breastfeeding against milk allergy Human milk oligosaccharides (not in formula): minimally digested in GI tract reach colon intact prebiotics healthy gut colonization anti-bacterial/viral/inflammatory Better mineral bioavailability: Lactalbumin: calcium and zinc Xanthine oxidase: iron and molybdenum Glutathione peroxidase: selenium Lactoferrin: iron Higher Ca:P Lower solute load (Mg, Na, K, citrate): less stress on infant’s kidney Disadvantages Environment contaminants (PCBs and dioxins) stored in maternal adipose tissue can be excreted in breastmilk: can interfere with vitamin K metabolism late hemorrhagic disease Low in vitamin K: if deficient, can develop immaturity to synthesize prothrombin injection of vitamin K at birth Drugs can be excreted in breastmilk: Social drugs risk dependency in infancy and there’s less milk production Anticonvulsants: infant may need K supplementation Smoking: decrease milk volume Low in vitamin D: need to take supplements Factors affecting breast milk composition Gestational age: Preterm milk: higher in protein, energy, NaCl, and lower lactose With increase length of lactation: higher lactose, fat, energy, water soluble vitamins, and lower total protein, Ig’s, fat soluble vitamin Malnutrition: Decrease immune factors in colostrum, but no effect on mature milk Fat soluble vitamins: excessive supplementation of vitamin D toxicity in infant Water soluble vitamins: infantile B12 deficiency in vegetarians, and infantile Beri-Beri- (B1 deficiency) if nursed by mother with it Protein-calorie malnutrition (PCM): if prolonged and severe, protein content affected Severe energy restriction: decrease milk volume (only factor doing it) Increased maternal body fat content: increase milk [fat] Insufficient maternal fat reserves during pregnancy: less fat content in breastmilk Severe hypercholesteremia: increase cholesterol in milk Composition of dietary fat: affect FA composition of milk fat More arachidonic acid (C20:4) in omnivores > vegetarians > formula More DHA (C22:6) in omnivore > formula > vegans Eating animal foods: changes linoleic acid (w-6) content of milk Vegetarians: >30% Omnivores: 6.9-18% Very low-fat diet: <1% risk of EFA deficiency if <6%, and increase proportion of C16 and LCFA Low maternal B6 intake: increase risk of B6 deficiency in infant and decrease its attentiveness Low vitamin C intake: decrease milk vitamin C Mineral intake: relationship between maternal intake of selenium and iodine, and breastmilk content Vegetarians/vegans: important to monitor protein (essential amino acid), w3, iron, calcium, vitamin D and B12 to make sure that milk have adequate supply for infant to thrive Requirements Water Increased AI based on median total water intakes: no evidence that renal function and hydration status are not equal during lactation: same for all ages Increased AI based on water content of milk: 14-18 < 19-30 < 31-50 years old Dietary fiber 14 g/1000 kcal x median energy intake Energy EER = EER + milk energy output/energy cost of milk– weight loss /energy mobilization Milk energy output 540 when 0-6 months vs 380 when 7-12 months Weight loss 140 when 0-6 months vs 0 when 7-12 months Theoretically, energy cost could be met by decrease physical activity or increase efficiency of performing routine tasks TEF don’t have effect Weight loss and energy mobilization from tissue not in all lactating women Recommendation unchanged Nutrients Explications AI Fluoride Very low [F] in milk + insensitive to difference in [F] of drinking water (supplements don’t affect F intake by infant, and F requirements of mother) Vitamin K No secreted significantly in milk, no effect on phylloquinone in milk Requirements for <18 < 18-50 years old Sodium and chloride Small amount secreted Chloride: equimolar amount RDA Magnesium Requirements for 19-30 < 31-50 years old Human milk not influenced by mother’s intake Milk [Mg] don’t change through lactation Increase bone resorption + decrease urinary excretion may provide necessary Mg for milk production Phosphorus Requirements for <18 > 18-50 years old Human milk [P] don’t decrease as lactation progresses Despite loss of milk, lactating women blood P levels high-normal/above-normal High blood P due to increase bone resorption + decrease urinary excretion + decrease blood PTH (high serum Pi) independent of dietary intake of P or Ca Calcium Requirements for <18 > 18-50 years old Primary source of calcium in human milk: increase maternal blood resorption + secretion of PTHrP due to lack of estrogen because of prolactin, independent of diet Increase mobilization from bone and decrease urinary excretion (increase renal conservation) is sufficient for milk production Dietary intake over recommendation don’t minimize bone loss Vitamin D Small quantity of maternal circulating vitamin D and metabolites in milk Based on when sunlight exposition is inadequate Recommendation decreased Nutrients Explications RDA Iron Adult: Fe secreted in mature human milk + basal iron losses = absorbed iron with 18% absorption Adolescent: Milk secretion + basal losses + expected growth of mother (Hb mass + Fe deposition in tissue) = absorbed iron with 18% absorption Requirements adolescent > adult Recommendation increased Nutrients Explications AI Chromium Secretion in milk Absorption 1% Manganese Secretion in milk Requirement don’t appear to be higher than non-lactating women, but median intake increase during lactation No deficiency observed in North American lactating women Choline Substantial amount secreted in milk + mechanisms for conserving maternal choline status not identify Increase 1st 6 months Pantothenic acid Secretion in human milk Decrease maternal blood [vitamin B5] when intakes are at non-pregnant AI Blood [B5] lower at 6 weeks and 3 months PP than control Biotin Secretion in milk Potassium Requirement for 14-18 <19-50 years old Based on highest median intake w-3 Secretion in milk from maternal tissues + diet Lower plasma and RBC lipid DHA: may be due to inadequate intake or normal response Supplementals with fish oild can be used Small amounts of EPA and DHA can reverse deficiency can contribute to AI w-6 No evidence that maternal dietary intervention has any effect on infant growth and development RDA Molybdenum Secretion in milk Iodine Copper Secretion in milk 65-70% bioavailability Selenium Secretion in milk Most selenium in milk: selenomethionine Bioavailability > 90% no adjustment for absorption Zinc Additional requirement + fractional absorption increase to 38% (vs 27% when non-pregnant) – endogenous zinc available Requirement for 14-18 >19-50 years old PP involution of uterus + decrease maternal blood volume release endogenous zinc available for reutilization during 4 1st weeks of lactation Vitamin E Additional amount of alpha-tocopherol in milk Supplements not necessary because infants deficiency rare Vitamin A To assure adequate body stores of vitamin A Almost doubled, only retinol considered (not carotenoids) Vitamin C Production in milk during 1st 6 months Requirement for 14-18 <19-50 years old Vitamin B12 Secretion in milk with adequate B12 status: 0-6 months > 7-12 months Low if no animal consumption in mother Folate Additional folate: milk volume x [folate] x bioavailability factor Vitamin B6 To ensure milk concentration of 0.13 mg/L 5X amount need to be consumed Additional requirement for lactation > amount secreted via lactation Niacin Preformed niacin secreted during lactation + energy expended involved in milk production In Nes because tryptophan niacin Thiamin Energy cost of milk production Carbohydrates Secretion in human milk Increase requirement since increase RQ and CHO utilization rates (preferred use of glucose by mammary gland) Must increase precursors for lactose synthesis, so need more glucose from ingested carbohydrates or increase amino acid to prevent utilization of endogenous protein for glucose production Protein Factorial approach: assumed lactation don’t alter protein requirement maintenance and protein and amino acid requirement increase in proportion to milk production Human milk: increase NPN 20-27% of total milk N Urea: important NPN component diversion of urea loss from urine + some colonic fermentation to milk and assumed that part of increase N needs to produce milk NPN will come from dietary protein Additional protein equivalent to human milk N output/incremental efficiency of N utilization + requirement for protein losses to conserve skeletal muscle to maintain milk production [Protein] in human milk not influenced by diet or body composition Chapter 6: Infancy and childhood Issues associated with milk feeding and the risks of different types of feedings Nursing period (4-6 months): exclusive breastmilk or infant formula Transitional period (6-10 months): intro of semi-solid foods (spoon) with high milk consumption Modified adult period (>10 months): most foods = adult type Milk feeding issues Breastmilk: high in fat Cow’s milk: not recommended in 1st year since low in fat, energy, vitamin and EFA Partly skimmed milk: not recommended in 1st 2 years because very low fat, energy, vitamin and EFA Risks Over dilution or under dilution of formula: under increases risk of dehydration, metabolic acidosis, hypernatremia Sterile water for formula: boil water for 2 minutes Microwaving formula: possible hot spots Nursing bottle syndrome: nocturnal and long-term use of bottles containing fluids other than water severe dental caries Inappropriate milk substitutes: Plant-based beverages (soy, rice): low energy density, imbalanced nutrient profile (low vitamin D and P compo failure to thrive), and Mn intake risk of neurotoxicity Goat’s milk: deficient in folic acid, vitamin B6 and B12, higher in protein risk of dehydration and higher renal solute load, low Ca:P risk of hyperphosphatemic tetany Timing of the introduction of solids coordinated in infancy with nutritional and developmental concerns Infants born with innate reflexes and ability to regulate food intake: should dictate eating schedule Cluster feeding: baby shifts from feeding every hours to every hours or in spurs most common in evening and young infants Intro of foods (weaning) If too early, risk of: morbidity (diarrhea and food allergies), undernutrition (normal decrease in maternal milk production), TDM, chocking If too late: growth faltering, decreased immune protection, undernutrition (inadequate energy and protein intake, deficiency in iron, zinc, vitamin A and D) Infant feeding skills development: Feeding position: semi-upright for bottle, spoon feeding when capable of controlling head and mouths 4-6 months: developmentally ready for new foods (Beikost) teeth have developed, ability to swallow solid foods, energy requirement can’t be met by breastmilk alone Indication of readiness: weight has doubled, consumes >32 oz of formula and still hungry, consumes 8 oz and still hungry <4h later, sits with support, control head movement, moving tongue from side to side, keeping head upright, sitting with little support Spoon: 1-2 tbsp of semisoft foods/meal 1 to 2 times/day when 6 months Sensitive to new tastes and smells High source of iron necessary twice a day from 6-12 months since low stores: iron-enriched baby cereal, meat and poultry, fish, tofu, legumes, eggs Weaning period: breastmilk + weaning foods to have more carbs and fat (have enough protein) Cup: 6 months 10-12 months: control cup + movement of tongue Transition to solid foods complete when food and liquids the infant takes in daily = calories in breastmilk Timeline 10 weeks: no extrusion reflex 3-6 months: palmar grasp 4 months: can move head forward and turn away 6-8 months: rotary chewing, critical period of development in relation to eating, requires specific stimulus of intro of solid foods 9 months: holds bottle 1-3 years: increase ability to eat child develops orally and muscularly Introduction of new foods: timing, reasons and rationales, risks and benefits of different foods. Introduction at beginning of the meals Crunchy is better for taste than overcooked One food at a time space out to see for allergies: wait 2/3 days before adding one Don’t force new foods or to eat 1 tbsp/year of age 1st 2 years: smaller portion, more frequent 6-8 months: stained and pureed meats, beans, eggs, fruits, vegetables and finger foods with palmar grasp 9-12 months: add texture to meals with table foods chopped and well-cooked foods, increase small finger foods as pincer grasp develops, add juice 4-7 months more accepting of new foods compared to ≥1 year preferences largely learned and sensitive to infant’s needs Nutrients RDA or AI Pregnancy Explication Lactation Explication Fluoride AI Unchanged High level of protection against dental caries Unchanged Very low [F] in milk + insensitive to difference in [F] of drinking water Sodium and chloride No evidence that decreasing it would prevent pregnancy induced HTN Chloride: equimolar amount of sodium Small amount secreted Vitamin K No evidence that usual intakes are inadequate Small amount secreted and no effect on phylloquinone in milk <18 < 18-50 years old Fiber Increased 14g/1000 kcal x median energy intake that is higher due to breastfeeding Pantothenic acid (vitamin B5) Secretion in human milk Biotin Increase metabolism + decrease urinary excretion Phosphorus RDA Intestinal absorption increases of 10% Unchanged Increase bone resorption + decrease urinary excretion + decrease blood PTH (P) + increase secretion of PTHrP due to lack of estrogen (Ca) <18 > 18-50 years old Calcium Increase efficiency of absorption Vitamin D Small quantity of 25(OH)D transferred to fetus Small quantity of maternal circulating vitamin D and metabolites in milk Vitamin E No evidence that supplementation would prevent deficiency symptoms (hemolytic anemia) in premature baby and no reports of deficiency during pregnancy Increased Additional amount of alpha-tocopherol in milk Chromium AI Increased Increase weight Secretion in milk with absorption 1% Manganese Secretion in milk: requirement not higher, but median intake increase during lactation Potassium Small increase during pregnancy 14-18 < 19-50 years old Water 2 approaches: Based on median total water intakes with no evidence that renal function and hydration status are not equal during lactation Based on water content of milk: 14-18 < 19-30 < 31-50 years old Choline Delivery to fetus through placenta from maternal stores Secretion in milk + mechanisms for conserving maternal choline status not identified EFA Incorporation into placental tissues and fetal for growth Secretion in milk from maternal tissues + diet Molybdenum RDA Increase weight Secretion in milk Magnesium Unchanged Increase bone resorption + decrease urinary excretion + human milk not influenced by mother’s intake 19-30 < 31-50 years old Copper Amount accumulated for fetus and products of pregnancy with a 65-70% bioavailability Increased Secretion in milk with 65-70% bioavailability Selenium Fetal deposition throughout pregnancy to allow accumulation of enough selenium by fetus to saturate its selenoprotein Secretion in milk as selenomethionine Iodine Uptake for maternal and fetal tissues Secretion in milk Zinc Increased requirement in 4th ¼ with 27% fractional absorption 14-18 > 19-50 years old Additional requirement + fractional absorption increased to 38% + endogenous zinc available for reutilization during 4 1st weeks of lactation due to PP involution of uterus + decrease maternal blood volume release 14-18 > 19-50 years old Protein Maintenance of additional protein stores + support of growth (protein deposition) Factorial approach: additional protein equivalent to human milk N output for NPN/incremental efficiency of N utilization + requirement for protein losses to conserve skeletal muscle to maintain milk production ([protein] in milk not influenced by diet) Vitamin A Accumulation in fetal liver + requirement increased during last semester with 70% efficiency of maternal vitamin A absorbed To assure adequate body stores of vitamin A as retinol, almost doubled Vitamin C Maternal plasma concentration decreases because of hemodilution + active transfer to fetus 14-18 < 19-50 years old Production in milk during 1st 6 months 14-18 < 19-50 years old Folate To prevent deficiency in blood [folate] and to prevent megaloblastic anemia + risk of NTD Additional folate: milk volume x [folate] x bioavailability factor Vitamin B12 Maternal absorption more efficient because of increased intrinsic factor B12 receptor + fetal deposition because only newly absorbed transported across placenta Secretion in milk with adequate B12 status: 0-6 months > 7-12 months Vitamin B6 Significant fetal uptake + increased weight + maintenance of plasma [pyridoxal phosphate] at non-pregnancy values with 75% bioavailability To ensure milk concentration for lactation (more than for amount secreted in milk) with 5X amount need to be consumed Niacin (in Nes) Increase energy utilization and growth Preformed niacin secreted during lactation + energy expended involved in milk production Riboflavin For milk production with 70% efficiency Thiamin Energy cost of milk production Carbohydrates Additional amount required in last trimester coming from the increased maternal storage of fat early pregnancy with increased glucose utilization by maternal-fetal unit due to less fasting maternal blood [glucose] and development of insulin resistance (ketosis) Secretion in human milk, so needs more glucose to synthesize lactose precursors + increased requirement due to increased RQ and CHO utilization rates because preferred used of glucose by mammary gland Iron Basal losses + iron deposited in fetus and related tissues + iron in expansion of Hb mass with 25% absorption Decreased Adult: Milk secretion + basal iron losses = absorbed iron with 18% absorption Adolescent: Milk secretion + basal losses + expected growth of the mother (Hb mass + Fe deposition in tissue) = absorbed iron with 18% absorption Adolescent > adult