Vitamin B + Choline + Electrolytes Requirements Pregnancy vs. Lactation Flashcards
B1 Requirement
Pregnancy: ↑ requirement by 30%: ↑ maternal/fetal growth (20%) and ↑ energy utilization (10%)
Lactation: ↑ requirement from B1 transfer into breastmilk + metabolic cost of milk production
Both RDA = 1.4 mg/d
B2 Requirement
Pregnancy: ↑ requirement by .3mg/day: ↑ maternal/fetal growth and ↑ energy utilization
- ↓ urinary excretion
Lactation: ↑ requirement from B2 transfer into breastmilk
- 70% use for breastmilk production efficiency
B3 Requirement
Pregnancy: No change in maternal requirement but ↑ RDA based on ↑ energy utilization + growth by 3mg/d NE
Lactation: ↑ requirement from preformed B3 transfer into breastmilk + cost of milk production
- wide variety in efficiency of converting Trp → B3
B5 Requirement
Pregnancy: AI pregnancy = AI non-pregnancy = 5mg/d
Lactation: ↑ requirement B5 transfer into breastmilk
AI = 7mg/d
B6 Requirement
Pregnancy: RDA ↑ due to fetal uptake and increased blood volume
- 1st trimester: + ~2mg, 2nd-3rd trimester: +4-10mg
- fetal accumulation, ↑ metabolic needs, 75% bioavailability
Lactation: ↑ requirement B6 transfer into breastmilk and ensure milk [B6] = .13 mg/L
- Mother must consume 5x amount –> milk [B6]
B7/Biotin Requirement
Factors which can affect requirement:
Pregnancy: AI for pregnancy = AI for non-pregnancy = 30 µg/d
- 50% of women show ↓ biotin excretion (unsure if due to low intake vs. need)
Lactation: AI ↑ requirement biotin transfer into breastmilk
Factors which can affect requirement:
- egg whites (avidin)
- biotinidase deficiency
- anticonvulsants (metabolize biotin)
B9/Folate Requirement
Pregnancy: Substantial ↑ in RDA: uterine enlargement, placental development, expansion of maternal RBC, fetal growth
- ↑ single carbon transfer rxn and nucleotide synthesis for cell division
- Adequacy indicator: RBC [folate] maintenance
- RDA 14-50 = 600 µg/d DFE
400 µg/d folic acid from fortified foods/supplements
Lactation: ↑ RDA: Milk volume x [folate] x bioavailability factor = 500 mcg/d
- 85 µg/day folate excreted into breastmilk
- 50% bioavailability dietary folate factor
B12 Requirement
Pregnancy: ↑ RDA to meet fetal deposition
- ↑ absorption and intrinsic factor/B12 receptors during pregnancy
- Serum [B12] ↓ to ½ [B12normal] by month 6 - not just due to hemodilution
- newly absorbed B12, maternal liver stores are less utilized by fetus
Lactation: Base RDA + amount excreted into breastmilk
Based on amount of B12 excreted into breastmilk by mothers with adequate B12 status
Choline Requirement
Pregnancy: AI ↑ choline requirements and depletion of maternal stores for fetus
- Required for embryogenesis and perinatal development and development of spatial memory (↑ demand for phosphatidylcholine)
- low choline –> high homocysteine + liver damage
Lactation: AI ↑ requirement significant choline transfer into breast milk, especially during first 6 months
- AI based on average choline content of milk
- higher than in pregnancy
Na requirement
Pregnancy: AI remains the same as non-pregnant
- small ↑ in requirement of 2.1-2.3 g accumulated over 9 months
- to maintain ↑ plasma volume
Lactation: AI no change = non-pregnant AI of 1.5 g/d
- based on highest median intake in pregnant women
K requirement
Pregnancy: AI ↑ to requirement during pregnancy but NO maternal requirement ↑
- Tiny potassium accretion during pregnancy
- AI based on highest median intake during pregnancy
Lactation: AI based on highest median intake in pregnant women
Same AI for both
Chlorine requirement
Pregnancy: AI is equimolar to Na AI requirements
Lactation: AI is equimolar to Na AI requirements
Same value
Nutrient requirements which increase due to increasing blood volume during pregnancy
Vit C, Folate, B6, Fe, Mg, Na, water
