Class Notes (1,100,000)
CA (620,000)
U of G (30,000)
NUTR (1,000)
NUTR 1010 (400)
Lecture 3

NUTR 1010 Lecture Notes - Lecture 3: Red Meat, Macrocytic Anemia, Low-Density Lipoprotein


Department
Nutrition
Course Code
NUTR 1010
Professor
Michelle Marcinow
Lecture
3

Page:
of 5
NUTR 1010
Lecture 26: Wednesday March 26, 2014
Zinc
oTrace mineral (less than 100mg/day)
oActs as a cofactor in 100 different enzyme reactions
Ensures proper functionality of enzymes and processes work
oFor metabolism
Needed for enzymes that metabolize CHO, fat, protein
oFor blood
Cofactor in an enzyme needed to create hemoglobin
No hemoglobin = no red blood cells = no oxygen getting into cells
-Without oxygen, you can’t burn CHO, fat or protein for fuel
oOther functions
Needed for enzymes that
-Fight oxidation
-Activates vitamin A in the eye
-Makes proteins and DNA
Critical for cell division and growth
-Especially for sexual maturation of en
-Affects how cells divide and grow
Needed for immune system function
oWhere do we find it
Sea food (especially oysters)
Meat (especially red meat), beans, whole grains
Bioavailability – absorb zinc better from animal foods than plant foods
oToo much
Does not happen from food
From supplements
-Pain, cramps, loss of appetite, diarrhea, low copper absorption,
decreased immune function
oToo little
Deficiency was first identified among men in Iran in 1950’s
These men suffered: stunted growth, mentally deficient, anemia, sexual
dysfunction
Rare in north America, but those consuming a vegan diet may not get
enough
-Skin and eye lesions
-Hair loss
-Low appetite
-Increased risk of infections
-In children: growth impairment
-In males: reduced sexual maturation or impotence
Folate and blood health
oWith vitamins B6 and B12, maintains normal homocysteine levels
Homocysteine = amino acid which increases blood coagulation and LDL
oxidation
About 10% of risk of developing cardiovascular disease due to higher
homocysteine levels
oSources
Liver, yeast, asparagus, oranges, legumes, fortified grain products
Absorb about 50% of folate we eat – DRIs take that into account
oToo much folate
No problems with consuming too much from naturally-occurring food
sources
Too much from fortified foods or supplements (folic acid form) can mask
vitamin B12 deficiency
Because of this, the Upper Level for folic acid = 1000µg/day
oToo little folate
Body will not be able to produce folic acid
Increased homocysteine levels
Impaired DNA synthesis and cell division, leading to macrocytic anemia
(larger)
Possibly neural tube defects in babies
oMacrocytic anemia
Signs – tired, pale, headache, irritable, dizzy, weak, loss of appetite
(leading to weight loss)
Reversible with folic acid supplements
Who is at risk
-Infants: those born prematurely, those fed goat’s milk (low in
folate)
-Elderly
-Alcoholics: alcohol inhibits absorption of folate
-Cigarette smokers: smoke inactivates function of folate
-People on certain anticancer drugs (methotrexate)
-Pregnant women
Vitamin B12 aka cobalamin
oWater soluble B vitamin involved in energy metabolism
oActivates folate
oLike folate, helps prevent macrocytic anemia and control homocysteine levels
oHelps make red blood cells
oMaintains nerve fibres – essential for healthy functioning of nervous system
(brain, spinal cord, nerves)
oSources
B12 bound to animal proteins, so found in animal foods only
Meat, fish, poultry, milk, eggs
Long-term vegans must take a supplement
oB12 absorption
Separated from animal protein in stomach due to action of gastric acid
Free B12 then binds to intrinsic factor