lactation nutritional requirements

Question 1

Why would different stages of lactation have different nutrient requirements?

Answer 1

Composition and amount of milk will change

Question 2

Does basal metabolic rate change in lactating women?

Answer 2

No

Question 3

How can a woman make up for the energy cost of lactation without any increase in intake? Why is this not the case for most women?

Answer 3

Lower physical activity

Most women are less active immediately after birth (rest and heal), but in following months it is highly variable

Question 4

the energy output needed for lactation is computed from __________ and __________.

Answer 4

amount of milk production

energy density of the milk

Question 5

How is the energy requirement for milk calculated?

Answer 5

(g of milk/day) x (0.67kcal/g)

Question 6

How is the EER for lactation period calculated?

Answer 6

normal EER of age group + energy output for milk - weight loss

Question 7

As the age of the infant increases beyond 6 months, the energy required for lactation will:

Answer 7

decrease (lower volume produced)

Question 8

How does the lactating mother’s body change in the 6 months post partum? Why does this occur?

Answer 8

• gradual weight loss (0.8kg/month)
• fat loss from subcutaneous region
  energy mobilization from fat stores
  *does not occur in ALL women

Question 9

When is the mother’s weight assumed to stabilize, and calorie reduction for weight loss no longer applied in the lactation EER?

Answer 9

after 6 months (weight loss calorie reduction = 0)

Question 10

The extra energy for lactation will come primarily from _____, not from ____.

Answer 10

maternal stores (fat)
not from diet

Question 11

Does protein intake affect milk protein concentration? The minimal amount needed is ____, in order to ______.

Answer 11

No

1g/day, to maintain SKELETAL MUSCLE, and produce adequate milk volume!

Question 12

The ____ approach is used for estimating protein requirements in lactation. What 2 assumptions are made?

Answer 12

factorial
assume:
1. amount of MAINTENENCE protein for mother does not change
2. amount of protein/AA needed for milk will increase as milk production increases

Question 13

True/False: There is a higher energy requirement for milk production in 0-6 months, so the EER for the mother will be greater than the EER after 6 months.

Answer 13

False: milk energy output is greater, but EER is reduced to allow for weight loss

Question 14

Is energy output considered when calculating lactation period EER?

Answer 14

Yes.

Includes normal EER, which accounts for estimated activity levels

Question 15

What non protein nitrogen compound in milk is notably important, and how is it produced (3)?

Answer 15

UREA

• Diversion from urine (given to milk instead of peed out)
• colonic fermentation of milk
• produced from protein/AA

Question 16

The total increase in needed protein is the sum of:

Can we use this number directly as the increase in EAR?

Answer 16

milk protein + milk NPN (conversion factor
No, need to account for protein conversion efficiency - only 0.47 efficient at turning diet protein into body protein
(need to divide by 0.47)

Question 17

How does the NPN content in milk affect protein requirements?

Answer 17

some protein is required to provide N for NPNs

use conversion factor of 6.25 to estimate amount needed

Question 18

The EAR of protein for lactating women (<6 months) is:

the RDA is:

Answer 18

1.05g/kg/day
multiply by 1.24 (CV = 12%)
RDA = 1.1g/kg/day (rounded)

Question 19

Protein is important to provide the protein and AA content in milk, but it will also provide ______, which accounts for 25% of the total milk ____.

Answer 19

convert to NPN (non protein nitrogen)

N

Question 20

Can higher omega 6 intake be beneficial for preventing deficiency in the infant through breastmilk? How is this reflected by the nutrient recommendations?

Answer 20

no evidence that increased intake by mother will have benefit

AI is given, since insufficient data
higher than nonpregnant AI, set as the MEDIAN intake in areas of no deficiency

Question 21

What nutrient is definitely needed in greater amounts during lactation, and why (2)?

Answer 21

Carbohydrates
mammary gland preferentially uses glucose
require high level of precursors (glucose) to make constant concentration of lactose in milk

Question 22

Small amounts of __ and ___ can help reverse omega 3 deficiency in infants, and can be counted as part of the ___ . Why?

Answer 22

DHA; EPA
AI
Less conversion of omega 3 required (spared)

Question 23

Why are the AI recommendations for omega 3 and 6 higher for lactating women, even though no evidence suggests increased requirements?

Answer 23

Based on MEDIAN intake in populations with no deficiency, happens to be higher

Question 24

Overall, for all age groups it is recommended to increase protein intake by ____ during lactation.

Answer 24

25g

Question 25

Lactating women will often have lower levels of ____ (LCFA) in RBCs and plasma. What could this indicate, and what has been found to increase concentrations in both mother and infant?

Answer 25

DHA could indicate inadequate intake; milk production is depleting maternal supply or could be normal physiological change/adaptation (hormones, nutrient transfer, fat metabolism) fish oil supplement

Question 26

In pregnant women, the ____ will increase, signifying an increase in ____ utilization.

Answer 26

RQ | carbohydrate

Question 27

omega 3s in breast milk are sourced from (2):

Answer 27

diet | maternal stores

Question 28

Are fibre requirements changed during lactation?

Answer 28

same calculation; slight increase due to increase in energy intake (14g/1000kcal)

Question 29

How is EAR and RDA determined for carbohydrates during lactation?

Answer 29

add amount of carbs needed to replace those given to milk to normal EAR (add 60g per day) multiply by 1.3 (CV of 15%)

Question 30

Is there an increased need for thiamine during lactation? Why or why not?

Answer 30

Yes | some is transferred to milk, some is used in the energy cost of milk production

Question 31

What is needed as a precursor for lactose? Where can this come from? (3)

Answer 31

Glucose carbohydrates from diet AA from diet (or proteolysis) glycerol from fat oxidation (very limited!)

Question 32

Daily milk production is about ____ L.

Answer 32

7.8 L

Question 33

Most nutrient requirements will ____ once the baby surpasses 6 months. why?

Answer 33

decrease | less feeding, introduce solids

Question 34

Is the requirement for riboflavin increased during lactation, and why or why not?

Answer 34

Yes; increase in EAR to account for 0.3mg put into milk each day (assume 0.7 efficiency, so increase amount by 0.4mg) calculate RDA as 1.2x = 1.6mg/day

Question 35

Can the body synthesize niacin?

Answer 35

Yes, to some extent, from Tryptophan

Question 36

a woman nursing multiple children would:

Answer 36

have higher milk production, have higher nutrient needs

Question 37

How are lactation and pantothenic acid status related (2)?

Answer 37

higher pantothenic acid intake -> more in milk | decreased pantothenic acid concentration in maternal blood in months following pregnancy (vs nonpregnant)

Question 38

Are there any differences in biotin requirements?

Answer 38

Yes, slight increase in AI to account for amount deposit in milk

Question 39

How do niacin requirements during pregnancy compare to riboflavin requirements?

Answer 39

Similar effects: increase in EAR to account for amount deposited in milk, and energy needs but: higher CV due to variability in converting Trp -> niacin

Question 40

True/False: Biotin requirements during lactation are not affected by age or lactation stage.

Answer 40

True

Question 41

Low intake of maternal B___ will lead to compromised status in the infant, especially since the secretion of this vitamin into milk is much less than the diet amount

Answer 41

B6

Question 42

Is the AI for pantothenic acid increased during lactation? Why or why not?

Answer 42

Yes, to account for amount deposit in milk and prevent decreasing concentration in mother *however, no evidence to suggest that normal AI would be inadequate

Question 43

for vitamin ____, the amount in the diet must be increased by much more than what is actually deposited in the milk.

Answer 43

B6 | diet increase is 5x more than amount that goes into milk

Question 44

Which B vitamins have an AI, and which ones have an RDA?

Answer 44

RDA: riboflavin, niacin, B6, folate, B12 AI: biotin, pantothenic acid

Question 45

what is the folate bioavailability factor for food folate?

Answer 45

2 | assume only 50% bioavailable, so need to eat 2x as much to get the DFE

Question 46

The secretion of vitamin B___ into milk will decrease after 6 months. Is this taken into account by the recommendations?

Answer 46

B12 | No; just calculated using higher amount

Question 47

Low B12 concentrations in breast milk are common in what 2 situations?

Answer 47

vegetarian mothers | poor populations with low meat consumption

Question 48

How are increased folate needs calculated? What is the RDA?

Answer 48

(amount deposit in milk per L) x (milk volume) x bioavailability factor (2) add that addition amount to the normal EAR assume CV = 10% -> RDA = 500 microgram/day

Question 49

The amount of vitamin ___ concentration in milk will decrease after 6 months, but recommendations will stay the same.

Answer 49

C and B12

Question 50

True/False: vitamin C requirement is higher in pregnant women than lactating women

Answer 50

False: lactating women have higher requirement

Question 51

The need for choline is (increased/not affected) by lactation. Why? (2)

Answer 51

increased (AI increased also) 1. substantial secretion into milk 2. no known mechanisms for increased conservation/absorption/synthesis in mother

Question 52

The increase in choline AI during lactation accounts for _____. An absorption efficiency of ____% is assumed.

Answer 52

amount deposited in milk | 100%

Question 53

vitamin A needs (increase/stay the same) during lactation

Answer 53

increase substantially

Question 54

Vitamin D needs (increase/stay the same) during lactation. Why? (2)

Answer 54

stay the same 1. small amounts secreted into milk 2. unclear what is minimal amount needed to maintain normal active vit D concentration in mother (no sign that requirements are increased)

Question 55

Vit D needs are higher if:

Answer 55

sunlight exposure is inadequate

Question 56

How is vitamin A requirement during lactation calculated? Why?

Answer 56

average amount received by infant per day (400 micrograms) add to normal EAR (EAR + 400RAE) To ensure adequate body stores of vit A in infant

Question 57

vitamin D needs are the same for all age groups except:

Answer 57

infants (less) | elderly (more)

Question 58

Can diet affect vitamin K status of breast milk?

Answer 58

From diet: no (no significant secretion into milk) | From drug supplements: yes, increase in phylloquinone

Question 59

The AI of vitamin K is (increased/not changed) during lactation. why?

Answer 59

not changed; no significant secretion into milk

Question 60

The median intake of vitamin E is much (higher/lower) than the estimated average requirement for lactation. Does this signify a problem?

Answer 60

lower NO: deficiency in vitamin E is very rare in breastfed infants vitamin E intake is usually UNDERREPORTED by mothers (actually consuming more); so real AI is likely higher

Question 61

Are renal function and hydration status affected by lactation? How is the AI set for water?

Answer 61

No | median intakes during lactation (increased to 3.8L per day of total water)

Question 62

Are vitamin E supplements necessary for lactation?

Answer 62

No; deficiencies are very rare in breastfed infants.

Question 63

The lactation EAR for vitamin E is calculated by:

Answer 63

adding amount secrete into milk to normal EAR

Question 64

True/False: lactation will result in some bone loss in the mother

Answer 64

True; but will be regained when ovaries become active again

Question 65

For sodium, a ___ amount is secreted into milk, and the AI is (increased/not changed). What mineral is equimolar in requirements?

Answer 65

small amount not changed (no diff in req) Cl (equimolar)

Question 66

Where does the calcium for breastmilk come from?

Answer 66

mostly bone resorption (mother's stores) | independent of intake

Question 67

True/False: the same number of grams of Na and Cl are needed per day

Answer 67

False: same number of MOLES, but weight is different (different molecular weights)

Question 68

Conversion of dietary K to milk K is very ____. How does this affect any changes in AI?

Answer 68

``` very efficient (100%) AI is increased by amount found in milk ```

Question 69

Does the RDA for Ca change for lactation? What are the physiological changes?

Answer 69

No 1. bone resorption -> Ca stores mobilized 2. Ca excretion decreased (renal conservation)

Question 70

What evidence shows that Ca absorption is not increased during lactation?

Answer 70

- levels of calcitriol do not increase in mother

Question 71

Can adding extra Ca in the diet help prevent maternal bone loss?

Answer 71

No; independent of diet; more due to lack of estrogen

Question 72

P is deposited into milk from where? What other mineral is similar to this?

Answer 72

from bone resorption, decreased urinary excretion | similar to Ca

Question 73

What mineral content will decrease in milk as lactation progresses?

Answer 73

Phosphorus

Question 74

During lactation, blood levels of P will (increase/decrease). Why? (2)

Answer 74

Increase! 1. increased bone resorption -> release into blood 2. decreased PTH -> more free Pi

Question 75

The minerals ___, ___ and ___ do not need increases in diet during lactation, and the increased needs are provided for by bone _____ and renal _____.

Answer 75

Ca, P, Mg | resorption; conservation

Question 76

Is more Mg recommended for lactating mothers?

Answer 76

No; same RDA. | Similar reasons as P and Ca

Question 77

estimation of Fe requirement for lactation is based on the ____ approach. What is considered? (2) And what needs to be done to convert this into a recommendation for diet?

Answer 77

factorial basal losses amount in milk account for absorption: divide by 0.18 (18% absorption efficiency)

Question 78

True/False: The concentration of Mg will decrease as lactation progresses

Answer 78

False; stays constant

Question 79

What factor for Fe requirement is not considered until after 6 months of lactation have passed? What additional factor is considered for adolescent mothers?

Answer 79

menstruation adolescent: growth - will need additional iron for tissues and Hb

Question 80

average absorption % of zinc in adult women is: | How does this change during lactation?

Answer 80

27% | increases to 38%

Question 81

what 2 factors after birth will contribute some extra Zn? is this reflected by the RDA?

Answer 81

- involution of uterus - decrease in blood volume release about 1 mg/day for a month for reutilization Not reflected in RDA, but can calculate yourself: subtract the extra Zn for FIRST 4 WEEKS

Question 82

How is the EAR for lactation Se requirements calculated?

Answer 82

Normal Se requirement + amount secreted into milk

Question 83

The secretion of what mineral is especially high in milk, compared to the normal intake of the mother?

Answer 83

Iodine; secretion amount losses is actually HIGHER than what normal intake would be!

Question 84

Most Se in milk is present in what form? Does it require a conversion factor for absorption?

Answer 84

Selenomethionine | No; absorption >90% efficiency

Question 85

Cu requirement during lactation is (increased/not increased). What is the assumed absorption efficiency?

Answer 85

increased (deposit in milk) | assume 65-70% efficiency

Question 86

The recommended intake requirements of ___ during lactation are more than double the normal requirements

Answer 86

Iodine

Question 87

Fluoride levels in milk are very _____. Is it affected by levels in drinking water, and is supplementation necessary?

Answer 87

low No No; does not affect intake in infant or requirements of mother (no AI change)

Question 88

The mineral ____ has extremely low absorption of 1%. How does this affect needs during lactation?

Answer 88

Cr | only 0.2microgram deposit in milk per day, but due to poor absorption should add 20 micrograms to previous requirement

Question 89

Does Mn requirement change during lactation? Is the AI affected, and are deficiencies common?

Answer 89

No (but 3mg deposit in milk per day) AI is higher (median intake happens to be higher) deficiency not common in North America

Question 90

The lactation RDA for Mo accounts for:

Answer 90

non lactating requirements + amount deposit in milk