Nutrition Flashcards
DRV
Dietary Reference Value
RNI
Reference Nutrient Intake
Amount of nutrient enough to ensure needs of 97% / nearly all group are being met
LRNI
Lower Reference Nutrient Intake
Amount of nutrient enough for small no. people who have low requirements (2.5%)
Not very useful, hardly used
DRV definition
Generally more accurate
Based on most scientific evidence and updated regularly
Take into account relationship between diet and chronic disease
Designed for healthy population groups (infants, children, adolescents, adults, pregnancy, older people)
Non-nutritive compounds example
Dietary fibre not absorbed by body,
Broken down by bacteria in gut to produce short chain FA which we can then absorb and convert to energy
Non-nigiri give compound example 2
Carnitine (animal muscle)
Photochemical such as carotenoids, flavonoids, methylxanthines and vasoactive amines.
Methylmercury found where?
Builds up in long-living fish
Teratogenic in pregnancy
Healthy diet is?
Provides sufficient energy and nutrients to maintain normal physiological functions, permit growth and replacement of body tissues
Prevents deficiency symptoms
Optimises body stores
Optimises some biochemical/physiological function
Minimises risk factor for some chronic disease
Minimises incidence of disease
Nutrient requirement factors
Age : increases til adulthood, decreases towards old age
Gender: males >protein and energy than females in adolescence and adulthood. Females require >Fe
Physiological state: during pregnancy,
folic acid requirement increases during first trimester
Fe requirement increases as pregnancy progresses
Genotype: polymorphism in enzymes involved in nutrient metabolism = requirements depends on individual
Environmental factors; smoking increases vitC requirement
RDA
Recommended Dietary Allowance
Recommended Daily Amount
EAR
Estimated Average Requirement
For energy or nutrient approx 50% need less/more
Used to estimate peoples energy requirements
SI
Safe Intake
Insufficient evidence to set another DRV
Level where no risk of deficiency and below level where risk of undesirable effects
VitE as RNI difficult to estimate here
Micronutrients
Trace elements, vitamins, Minerals
Soluble vitamins?
Is vitamin B12 soluble?
Water-soluble vitamins absorbed passively except VitB12
VitB12 requires intrinsic factor for receptor mediated endocytosis in terminal ileum
Fat-soluble vitamins carried in micelles and absorbed passively with end products of fat digestion.
Body’s storage of vitamin B12 in body
3-6 years
