Flashcards in Lecture 15 - Nutrients for Blood Health Deck (56)
What is the composition of blood?
55% plasma (mostly water)
<1% white blood cells
45% red blood cells
Why is vitamin K important for blood health?
Vit K is a coenzyme in the synthesis of proteins involved in blood clotting
-also coenzyme in bones
What are the 2 groups of vitamin K and how do they differ?
Phylloquinone (plant form)
Menaquinone (bacteria in gut)
What are sources of vitamin K?
Green leafy veggies, soy beans, canola oils
What is the deficiency accosted with low vitamin K?
Lack of normal blood clotting
Who is more at risk of developing vitamin K deficiency?
How many pathways are involved in blood clotting?
Many pathways lead to the same destination
How many proteins that are involved in these pathways are associated with vitamin K?
4 proteins in the pathways require vitamin K to become active
What are the 2 states of Fe, and how do they differ?
-body absorbed this Fe in the reduced state
Can Ferrous and Ferric Fe convert back and forth?
Yes, very easily
What is the difference between myoglobin and hemoglobin?
Myo: transports O2 to muscles and only has 1 subunit
Hemo: transports O2 in blood and has 4 subunits
Where do you find the highest source of heme Fe?
In blood and muscle products
In a piece of meat, what % if heme vs non heme Fe?
40% Heme iron
60% non-heme iron
What is the % of heme vs non-heme in food that isnt meat?
100% non heme Fe
How is Fe absorbed?
Fe goes into intestine and in mucosal cells of intestinal wall. If body doesn't need Fe it stays in cells until they die and are excreted (Fe included). When the body needs Fe it is bound to ferritin (storage protein) in the mucosal cells until the body sends transferrin to pick up the Fe to take it into the blood
What is our need for Fe dependent on?
Need for Fe
Whether Fe is heme vs non-heme
What is the absorption rate of heme vs non heme in veggie vs mixed diet?
Average absorption of mixed diet= 18% Fe
Average absorption of veggie diet= 10%
What are the factors that enhance Fe non-heme absorption?
MFP: When animal flesh is consumed it helps to increase absorption of non heme
What are factors inhibiting the absorption of non heme Fe?
Phytates- in fibre
Ca- with Fe inhibit each other
Polyphenols- All plant chemicals that give plants their colour
What is transferrin?
Transport protein of Fe that takes Fe to other tissues and bone marrow
What is ferritin?
The protein within the mucosal cells that hold Fe
What is hemosiderin and what does it do?
Stores iron at high levels only
-slowly releases iron to protect the body against free radicals
What is the lifecycle of Fe like?
Lasts for 4 months on hemoglobin then enters thee spleen and liver to dismantle the molecule for degradation or recycling. Fe is salvaged, transferred to transferrin and travels back to the bone marrow to be reused for red blood cell synthesis.
How do losses of fe occur?
Gi tract, blood loss, little from urine, sweat or skin loss
How is the iron balance in the blood regulated?
What does hepcidin do?
Recognizes how much Fe is in the blood and lets intestines know how much to absorb (limiting absorption from SI).
-also controls how much of transferrin is made?
What is the most common deficiency in the world and Canada?
Who is most vulnerable to Fe deficiency?
Children in growing years
Women in child bearing/pergrnancy
How is blood lost?