Macronutrient + Vit A, C, D, E, K Requirements Pregnancy vs. Lactation Flashcards
Energy Requirements
Pregnancy: EER = TEE + Energy cost for tissue accretion
- ↑ BEE due to metabolic contribution of uterus/fetus + ↑ cardiac/pulmonary activity
- Fat free mass (FFM) strongest predictor of BEE
- 2nd/3rd trimester EER includes: pre-pregnant BMI, weeks pregnant, age, height, weight, and PAL
Lactation: EER = Adult/Adolescent EER + Milk Energy Output - Weight Loss
- Based on milk production and energy density of milk, stage of breastfeeding, activity levels
- 0-6 months: .67 kcal/g milk → 541 kcal/d in energy cost of lactation - 141 kcal weight loss = 400 kcal
- 7-12 months: 380 kcal/d
Protein Requirements
Pregnancy: ↑ protein requirements for: support growth of new maternal/fetal tissues and maintain them
- negligible 1st trimester
- +25g av 2-3rd trimester
- takes into account protein to maintain ↑ BW + conversion to lean mass deposition
- new studies suggest protein req is higher: 1.2g/kg 1st trimester, 1.5g/kg 2nd trimester
Lactation: [Protein] in milk not affected by diet or body composition → but req ↑ to maintain mother’s skeletal muscle
- assessment of adequacy by factorial method
- base protein requirements DON’T CHANGE and ↑ based on milk prod
- +25g per day av
CHO Requirements
Pregnancy: RDA ↑ to accommodate for: ↑ metabolic rate and ↑ early fat storage
- adaptations to maternal glucose metabolism
- RDA ↑ = 175g/day
Lactation: Requirement based on ↑ respiratory quotient and CHO utilization rates
- Mammary gland preferential use of glucose
- Human milk lactose content of ~74 g/L from: precursor glucose or AA (except Leu/Lys)
- RDA lactation = 210 g/day of carbohydrates
Fat Requirements
Pregnancy: n-6 AI ↑ 13g, n-3 ↑ 1.4g
- based on median w/o deficiency
- association with vegetarian diets → high AA, low DHA w/ possible brain development concerns due to competition for desaturase (n-6 outcompetes)
Lactation: EFA AI requirements both ↑ n-6 –> 13g/day, n-3 –> 1.3g/day
- Linoleic is diet independent (AA levels adequate among all diets)
-a-linolenic milk content from maternal tissues and dietary intake
- supplementation of DHA ↑ plasma concentrations in mother/infant
Fiber Requirements
Pregnancy: Same benefits as in non-pregnant women –> AI ↓ CVD risk, increased benefits with intake
- adjusted for high kcal requirements
Lactation: same as preg/non-preg
AI = 14g/1000 kcal
Water Requirements
Pregnancy: AI ↑
- based on median intake
- wide variation
Lactation: AI based on median sufficient intakes - includes additional water for milk
- No changes in renal function or hydration status during lactation
Vitamin A Requirements
Pregnancy: ↑ requirements to meet accumulation in fetal liver by last trimester
- assumption that liver contains ½ body’s vitamin A when stores are low
- 70% maternal vitamin A absorption
- highest accumulation in last 90 days of gestation
- Additional 50 µg + non-pregnant RDA
Lactation: ↑ requirement vitamin A transfer from mother’s stores into breastmilk (first 6 months) and avoid depleting maternal stores
- no dietary intake –> milk content
- Conversion of carotenoids in milk and in infants is unknown so RDA is based on retinol only (not carotenoids)
Vitamin C Requirements
Pregnancy: ↑ vitamin C requirement due to hemodilution + transfer to fetus → maternal plasma ↓ [vit C]
- EAR estimated based on requirements to prevent scurvy in young infants = 7mg
- women who smoke, use drugs, drink heavily or regularly use aspirin ↑ requirements
Lactation: ↑ requirement vitamin C transfer into breastmilk (first 6 months)
Vitamin D Requirements
Pregnancy: No ↑ to requirement
- small amounts 25(OH)D transferred to fetus - minimal effect on maternal status
- higher intake recommended
- RDA = 600 IU/15 mcg
Lactation: Small amounts of vitamin D and metabolites enter milk - no evidence for lactation increasing mother’s RDA
- RDA = 600 IU/15 mcg
- Vitamin D supplementation 10 µg/d to exclusively breastfed infants
mothers can also supplement with up to 100 µg/d to increase milk content
Vitamin E Requirements
Pregnancy: No ↑ in RDA requirement
- Only concern is deficiency in premature infants → hemolytic anemia
- maternal supplementation has no effect
Lactation: RDA↑ requirement for a-tocopherol content of breast milk
- based on average content of a-tocopherol in breastmilk
- deficiency in breastfed infants is rare
Vitamin K Requirements
Pregnancy: No ↑ in requirement during pregnancy
- AI >19 years pregnant/non-pregnant = 90 µg/d
Lactation: No change in AI for lactation
only pharmacological doses of vitamin K ↑ phylloquinone in milk, not dietary intake
Adaptations to maternal glucose metabolism during pregnancy
↓ fasting maternal [blood glucose]
Developed insulin resistance
Tendency towards ketosis (fetal brain can utilize ketoacids)
↑ respiratory quotient (CO2/O2) to ↑ glucose utilization by fetal-maternal unit
- ~70% glucose oxidation for fetal brain requirements
