Lecture 15 - Nutrients for Blood Health Flashcards
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?
Newborns
Elderly
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?
Ferrous (++)
-body absorbed this Fe in the reduced state
Ferric (+++)
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
Vitamin C
What are factors inhibiting the absorption of non heme Fe?
Phytates- in fibre
Vegetable proteins
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?
Hepcidin
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?
Iron
Who is most vulnerable to Fe deficiency?
Children in growing years
Women in child bearing/pergrnancy
How is blood lost?
GI disorders Menstruation Blood donation Ulcers Accident/Surgery Parasitic infection
How do you assess Fe deficiency?
In stages
What are the 3 stages of Fe deficiency?
1st- decreased levels of stored Fe causing decrease ferritin levels, but everything else is normal
2nd- Fe transport affected, not picking up Fe in the blood but levels of transferrin increase
3rd-body isnt able to make hemoglobin= decrease in hematocrit (packed red blood cells)
What is microcytic anemia?
Fe deficiency result in small RBCs that do not carry enough hemoglobin
- RBC pale in colour
- can have less #’s but not necessarily
- you have enough Fe but it can’t get the Fe to where it needs to go
What is macrocytic anemia?
Large RBCs caused by B12 or folate deficiency. Causes lac of intrinsic factor being made in the stomach
-can also be due to lack of Fe consumption but usually not the case.
What is the main type of microcytic anemia?
Pernicious anemia
What is a major symptom of microcytic anemia?
Neurological symptoms which while the anemia can bee reversed the euro symptoms can not
What is hemochromatosis?
Iron toxicity, most common genetic condition that causes unneeded Fe to be absorbed (hepcidin doesn’t work to control Fe absorption)
What can hemochromatosis lead to?
Hemosiderosis
What is Fe overload?
Too much Fe in the organs
What is the RDA of Fe for men and women?
Men: 8mg/day
Women: 18mg/day
-values are 1.8x higher if vegetarian, if female and if pregnant
What and where do you get Fe contamination?
When Fe leaks into food when cooking with Fe pots
-(is a good thing)
What are the best forms of Fe supplementation?
Ferrous sulphate or Ion chelate (better because bound to AA or sugars)
What is the problem with Fe supplements?
They are in the ferrous form (which is good for absorption) but they are less well absorbed
-Vit c has no affect of Fe supplement
What are sources of Fe?
Beans, legumes, meat, fortified grains consumed with foods high in vitamins c
What is Zn role in the body?
Cofactor for many enzymes Is a metalloenzyme Immune functions (sore throat) Blood clotting Wound healing
What does the absorption of Zn depend on?
Zn status (high status=less absorbed)
How is Zn absorbed?
Enters mucosal cells in intestines. If the body doesn’t need Zn it is excreted via feces. If the body needs it it is brought in. Zn is stored as metallothioneinor transported to the pancreases (via albumin or transferrin)
What is thenteropancreatic circulation?
Circulation of Zn when it is absorbed in the intestine, transported to the pancreases and incorporated into digestive enzymes and helps with insulin. Which the digestive enzymes are excreted back to the intestines
Can people become deficient in Zn?
Yes, rare but in vulnerable populations
- poor physical growth
- poor cognitive and motor development (common in children)
- Impaired immunity
- poor wound healing
Why is there a UL for Zn?
40mg/day is set based on the potential for Cu deficiency
What are sources of Zn?
Anything that has protein
Why is Cu important in blood?
Cu is apart of many enzymes involved in O2 consumption
What is Cu main job related to blood?
Involved in the enzyme that converts ferrous to ferric
-allows Fe to bind transferrin
What are the 2 diseases associated with Cu deficiency?
Menkes disease (kinky hair): Cu is involved in the enzyme that forms collagen. So if it doesn’t get made right it causes kinky hair. Diagnosed in children and associated with Cu deficiency, where it is absorbed but doesn’t get to the blood. Treated with Cu shot
Wilsons disease: Allows more Cu absorbed which can build up in organs causeing Cu toxicity. Diagnosed in adults. treated with high doses of Zn
-both are genetic
What are sources of Cu?
A lot of different things
Do we need other trace minerals?
They do have functions in the body but dont know another mineral could take over as a part of the enzyme.
-we dont know how essential they are
What are contaminant minerals?
Heavy metals- lead, mercury, cadmium all interfere with nutrient functions/ can replace other minerals
-Enzymes and proteins associated with the good minerals are replaced by heavy metals causing them not to work
