Micronutrient Requirements during Pregnancy Flashcards
What major physiological adaptation takes place for Calcium in pregnant women and why?
Increased efficiency in intestinal absorption (double!),
for the increased demands because a lot of calcium is transferred to the fetus
True or False. Vitamin D levels decrease during pregnancy.
False, they increase
What factors increase the levels of calcium absorption?
not likely happening here because of vitamin D
Not because of diet high in Calcium
know that somehow absorption is increased
probably because of calciotropic hormones (play a role in bone growth and remodeling)
True or False. Number of pregnancies affects your bone mass.
False. No correlation has been found between numbers of pregnancies and bone mineral density.
Why is Phosphorus RDA the same during pregnancy?
No evidence to support an increase.
True or False. The absorption of phosphorus increases during pregnancy.
True
What happens to the concentration of Magnesium in the blood during pregnancy?
It decreases
Why does the concentration of Magnesium in the blood decrease during pregnancy?
likely because of hemodilution, not magnesium status
What physiological changes related to magnesium happen during pregnancy?
Unlike other minerals, there is NO increased absorption
and NO extra conservation
What is the increased pregnancy requirement for magnesium based on?
Weight gain (lean mass) of pregnancy under assumption that increased weight means more magnesium
What factors are included in the factorial method of calculating iron requirement during pregnancy?
Basal Losses
Fe deposited in fetus and related tissues
Fe in expansion of Hb mass
At which point in the pregnancy is there the greatest need for iron? Why?
3rd trimester
least at first because least growth
True or False. The absorption rate of iron for a pregnant women increases as the pregnancy progresses.
True
A iron anemia can lead to what?
Perinatal Maternal mortality for severe
even moderate has increased rate of deaths
from heart failure, infection, hemorrhage
also perinatal infant mortality
a high Fe serum concentration can we associated with what?
adverse pregnancy outcomes like SGA
could be because low plasma levels (which could be signs of preeclampsia or hypertension)
A low Fe status can lead to limited Hb for the mother, how?
Limits the mother’s ability to produce Hb for herself.
Could the mother use her own stores to supply Iron to the fetus if her stores are sufficient?
Yes to some degree. The mother can supply some of the requirement from her stores to the fetus but it isn’t optimal.
Is the maternal skeleton used as a reserve to provide Calcium for the fetus?
No, the maternal skeleton is not used as a reserve
What change for calcium intake is required for pregnant women?
None, no increase
What change is there for the magnesium requirement?
increase
Iron stores are directly correlated with what aspect of the baby?
birth weight
Why are Fe supplements recommended?
The normal Canadian diet cannot meet Fe RDA.
True or False. The iron recommendation for pregnant women despite no more menstrual losses.
true
When would Fe supplementation not be necessary? (even though we don’t take the chance)
normal stores before pregnancy because supplementation works under the assumption that they are inadequate
How are the requirements for Iron made for pregnancy?
uses the estimates for requirement for third trimester, then applied to whole pregnancy to establish stores at the beginning
Is there a change in requirement for potassium?
no
Is there a change in sodium requirement?
increase to maintain plasma osmolality
Why is the AI for Sodium the same for pregnant and non pregnant women?
The change per day would be way to small for it do be significant
What is the requirement for chloride based on?
equi-molar with sodium
Do pregnant women have a different sodium UL than non pregnant women?
no because not enough evidence to support that it would have health benefits
What happens to the requirement of Thiamin? Why?
Increases
account for more growth in maternal and fetal compartments
increased energy utilization
What happens to the requirement of Riboflavin and why?
Increased
more growth and energy utilization
What happens to the requirement of Niacin and Why?
increased
What is the change in niacin requirement based on?
no evidence for need of the change but it was estimated based on growth and energy utilization increase
True or False. There is a minimum amount of fetal uptake of vitamin B6.
FALSE, significant
Supplementation during pregnancy of B6 is necessary to maintain plasma [ ] ?
pyridoxal phosphate
What is the increased need of B6 based on?
avoiding negative effects
but you can also look at physiological changes affecting needs
How do folate requirements change and why?
increased
more single-carbon transfer reactions and cell division (nucleotide synthesis)
How do we know that folate is actively transferred to the fetus?
higher concentration of folate in the cord blood than the maternal blood
What happens with inadequate folate intake?
maternal serum and erythrocyte folate decreases
leads to megaloblastic marrow changes which leads to megaloblastic anemia
How is folate adequacy in pregnant women measured?
same as in non pregnant, erythrocyte folate concentration
What is the EAR of folate based on?
the ear of non pregnant women + a set amount based on studies (this amount alone is inadequate)
What happens to the absorption of B12?
increases because of more intrinsic B12 receptors
What happens to the serum B12 during pregnancy?
decreases (cannot be justified by hemodilution)
What is the most important source of B12 for the fetus?
current diet intake,
maternal stores are less important because only newly absorbed B12 is readily transported across the placenta
What is the most important source of B12 for the fetus?
current diet intake,
maternal stores are less important because only newly absorbed B12 is readily transported across the placenta
What changes happen in the normal physiology of biotin during pregancy?
increase in biotin metabolite (3-hydroxyisovaleric acid)
decrease in excretion of biotin
ratio of metabolite/biotin in ruine increases
what happens to the requirement of Biotin?
nothing, so many factors don’t know if it changes up or down
What factos affect biotin requirement?
raw egg whites (avidin
biotidinase deficiency
anticonvulsants
pregnancy
What happens to the Choline requirement and why?
increase, we know because a large amount of choline delivered to fetus which can deplete maternal stores
What happens to the choline requirement and why?
Nothing, not enough info that usual intakes are not enough
What happens to vitamin C requirement?
no precise data on how much vit C is transferred, so we added the amount to prevent scurvy in small children to normal requirement
What happens to vitamin C during pregnancy?
Decreased serum vitamin C
because of hemodilution and transfer to fetus
What happens to vitamin C during pregnancy?
Decreased serum vitamin C
because of hemodilution and transfer to fetus
What happens to vitamin A requirement during pregnancy?
increased
What is the EAR for vitamin A during pregnancy based on?
accumulation in fetal liver
absorption is about 70%
accumulates mostly in last 90 days
What is the vitamin A UL for pregnant women based on compared to normal women?
teratogenicity vs liver abnormalities
What happens to the Vitamin D requirement during pregnancy?
nothing
What happens to vitamin E requirement during pregnancy?
Same
Is vitamin E deficiency for newborns possible?
yes
premature newborns
no reports during pregnancy
no evidence that supplementation would prevent it in premature newborns
What happens to the requirement for vitamin K during pregnancy?
nothing
