Trace minerals,fat soluble vitamin and antioxidants Flashcards
Zinc function
- DNA and protein synthesize( regulates how our genes are expressed)
- Release of vitamin A from stores
- Synthesize,storage,release of insulin ( in the pancreas)
- Taste perception
- Free radical protection(antioxidant)
- RBC synthesis- heme,blood clotting
- Immune function, wound healing,pressure ulcers
- Growth and development, reproduction
- Influences behavior and learning
One of the early signs of zinc deficiency
Loss of taste
When people lie in bed for a long time without movement
Pressure ulcers and bedsores
Zinc function as metalloenzyme. Give a definition of metalloenzyme
Enzymes that function with trace metals, they help them to function faster and more effectively. In other words, cofactors
What foods are the best sources of zinc?
Animal sources as they have high content and have the best bioavailability
Sources of zinc in food
Beef, eggs, Seafood( oysters the best source of zinc),dairy, legumes
RDA and UL for zinc
RDA men-11 mg/day
women -8 mg/day
UL-40 mg/day
How can be UL for zinc be achieved
By getting supplements
Describe the pathway of zinc when it gets in the body
- Zinc is released from ligands in which it was bound in food because of the acidity
- It goes to mucosal cells, where it can be stored in the form of metallothionein
If the body needs zinc what happens
Metallothionein releases zinc to albumin and transferrin to transfer around the body
If the body does not need zinc what happens
Zinc is not absorbed and excreted in intestinal cells instead, the zinc absorption is decreased
Where zinc goes from the blood
The pancreas uses zinc to make digestive enzymes
What happens to zinc in digestive enzymes and what is the consequence of that?
It gets reabsorbed, so it takes a lot of time to become deficient in zinc
What are the enhancers in zinc absorption
Acids
Amino acids
Zinc absorption inhibitors
Phytate Oxylate Polyphenols(chocolate) Fibre-insoluble Other divalent cations ( Ca,Fe,Cu) Folate H2 blockers that reduce acidity
What is the absorption range for zinc?
15-40%
Total body zinc content is controlled between
-Absorption efficiency of dietary zinc and endogenous circulation in pancreatic fluid
What happens to absorption of zinc at low intakes?
Increases, also recycling from pancreas to small intestine
How do we lose zinc?
- Endogenous fecal losses increase several times at high intakes
- Sweat
Steps in dietary zinc deficiency
Increased losses/decreased intake ——->increased absorption/decreased losses—–>Tissue zinc conservation——>Mobilization of zinc from exchangeable pool——>General tissue disfunction
Is it easy to diagnose zinc deficiency ?
No, because it is so connected with GI, it is in bones,blood, but in small quantities. No sensitive or specific test
Why zinc deficiency often diagnosed as PEM (protein energy malnutrition)
Because of zinc deficiency diarrhea can happen that we exacerbate PEM
What happens with zinc deficiency and the most vulnerable population
- Compromised growth and development
- Poor appetite
- Immune system and CNS dysfunction
- Widespread in developing world
- Children are most vulnerable
Is zinc deficiency common in Canada? why?
Not so common, because usually foods gets zinc from the soil. Now, when we get food from a variety of places-> not a problem
Symptoms of zinc deficiency
- Nausea,vomiting,diarrhea, interference with copper metabolism
- Can cause iron deficiency
- Increased intestinal metallothionein
- Reduced immunity,urinary problems
What is the take-home message for zinc?
Try to meet the needs from the diet
Iodine is a part of what hormone
-Thyroxin-thyroid hormones (T3 and T4)
Thyroxin : function
- Metabolic rate of every cell
- Body temperature
- RBC synthesis
- Growth,reproduction
- Brain development
What is the RDA and UL for iodine
RDA- 150 microgram
UL-1100 microgram
What was done in order to prevent iodine deficiency and did it solve the problem?
-Iodized salt( in 2 g the RDA, the usual adult intake is 8g/day)
How many people is deficient in iodine?
200 million people
Diseases from iodine deficiency
- Goiter
- Cretinism ( when iodine deficiency during pregnancy)
Food sources of iodine
- Seaweed and seafood
- A little in dairy now, because the machinery are cleaned with iodine solution
Iodine regulating pathway
1) hypothalamus produces thyroid regulating hormone (TRH)
2) TRH signals pituitary gland to synthesize TSH( thyroid stimulating hormone)
3) TSH initiates T3 and T4 synthesis
When there is not enough iodine and T3 and T4 are not produced in the desired quantity, what happens
There is a feedback to hypothalamus to secrete more TRH. The whole pathway of iodine repeats. Enlarged thyroid gland, because it tries to satisfy the needs
Should you take supplements for iodine?
No, meet your needs with diet, if deficient , will be corrected with drugs
Iron and Zinc interactions
Iron overload—->Fe occupies all transferrin binding sites->decreased Zn absorption and transport
Zinc and Copper interactions
High diet in Zinc—-> high metallothionein-> Cu is bonded more strongly—-> not released from mucosal cells
Protein and Zinc interactions
Low protein—> low albumin—–>less Zn released from mucosal cell—->more growth,failure,immune disfunction
Where vitamin K can be found
Food sources: green vegetables(cauliflower, cabbage,canola oil,spinach, soybeans,lettuce) , liver, milk
-Produced in colon bacteria, but not in sufficient amounts, so still a vitamin
Other names for vitamin K
Phylloquinone,menadione
Vitamin K functions
- Synthesis of bone proteins to enable Ca binding( osteocalcin to maintain mineralization)
- Blood clotting-Prothrombin
Deficiency of vitamin K can be caused by
- Fat malabsorption
- Newborns( as they do not have microbiota yet, and there is little vitamin K in the breast milk)
- Antibiotic use kill off vitamin K producing bacteria
What would happen without vitamin K?
We would bleed out
What does vitamin K do in the blood clotting?
It activates conversion to prothrombin
Prothrombin—–>Thrombin
Thrombin converts Fibrinogen to Fibrin
Is there a UL for vitamin K?
No
What is Warfarin?
Anticoagulant
What is the concern for people who take Warfarin?
They should maintain the intake of vitamin K, because sudden changes of Vit K from food can affect the potency of medication
What is the antidote for too thin blood?
Vitamin K
What is antioxidant?
A molecule that have a free electron to calm down unpaired electrons in radicals
How can radicals occur?
From the oxidation process in the body
What are the consequences of oxidative stress?
Damage to DNA, proteins,lipids
As the result->cancer, CVD,compromised immune function,cataracts
What lipids can be easily oxidized by free radicals and where
PUFAs in the cell membrane
What happens when DNA and RNA are influenced with free radicals
-Absence of specific proteins, excess of specific protein
What happens with proteins are influenced by free radicals
Impaired cell function
Inflammatory responce
How many children are deficient in Vitamin A
100 millions
If vitamin A is taken in adequate doses then,
It decreases fatality from measles
Prevent blindeness
What happens with vitamin A toxicity
Birth defects
What is the precursor for vitamin A
Caratenoids and especially, beta-carotene
Three forms of vitamin A and the difference
- Retinol( alcohol form)
- Retinal ( aldehyde form)
- Retinoic acid ( acid from)
RDA for vitamin A
men - 900 micro RAE
women -700 micro RAE
How much beta-carotene is needed for 1 vitamin A molecule
12
Where caratenoids and retinoids can be found
In vegetables -caratenoids
Retinoids-animal food
How vitamin A is stored?
In the form of retinol
The pathway of vitamin A in the body
-Retinoids—->retinol(supports reproduction)
Carotenoids —->Retinal ( participates in vision)
RetinolRetinal—->Retinoic acid (regulates growth through cell differentiation and DNA function)
The first sign of vitamin A deficiency is
Night blindness
Describe the role of vitamin A in vision
Pigment in the retina has rhodopsin, which associated with cis-retinal. When rhodopsin absorbs the light, cis -retinal is converted to trans-retinal—>brain signal
Vitamin A deficiency : consequences in vision
- Nightblindness (retinal)
- Bitot’s spots ( retinoic acid)
- Xerophthalmia- the eye loses flexibility, dry of the eye and tear ducts ( retinoic acid)
- Keratomalacia-the cornea-the front of the eye, becomes clody and softens (retinoic acid)
Vit A deficiency and skin
-Hyperkeratosis- when the surface of the skin becomes very rough
Vitamin A and mucous membrane
Vitamin A maintains healthy cells in mucous membranes
Without vitamin A, the normal structure and function of the cells in the mucous cells are impaired
Retinoic acid function
- Cell differentiation by gene expression regulation
- Affects embryotic development
- Function of goblet and epithelial cells( mucous membrane lining defensive barrier)
- Immunity( epithelial defense+ direct immune system)
- Growth( cell division, bone remodeling)
Deficiency of retinoic acid
- Decreased membrane integrity,taste,digestion,absorption
- Stunting
- HIV,malaria
- Upper respiratory tract infections, diarrhea
Retinoic acid toxicity
-Malformation in all organs during pregnancy
Can you become toxic of vitamin A from beta-carotene? then how you can
No
From liver,fortified food, supplements
When does vitamin A toxicity happen?
Develops when binding proteins are loaded and vitamin A is free to damage the cells
Who is the most vulnerable to vitamin A toxicity?
Children
UL for vitamin A
3000 micro grams RAE
What happens with vitamin A toxicity
Bone and birth defects
Hip fractures in postmenopausal women
Best sources for vitamin A
- Liver ( careful how much you eat)
- Sweet potato
- Mango
- Carrots
- Brocolli
- Fortified food
How to increase vitamin A status
- Eat more vitamin A rich foods
- Shot every 6 month
- Fortify food supply
- GMOs( golden rice)
Why you need to drink fat milk?
Because fat soluble vitamins are better absorbed with fat (e.g. vitamin A)
Another name for vitamin C
Ascorbic acid
Function of vitamin C
- Collagen in skeletal: bone,teeth development,scar tissue,wound healing
- Hormone synthesis
- Antioxidant,reducing agent
- Cofactor with many reactions: hormones, neurotransmitters ( serotonin)
- Immune system:antioxidant
What happens with vitamin C deficiency?
Scurvy- scorbutic gums-> loss of teeth
also pinpoint hemorrhages( small red dots in the skin)
What is RDA for vitamin C, UL
RDA men-100 mg
RDA women-80 mg
UL- 2000 mg
Why smokers need higher Vitamin C?
Because of the free radicals
The best food source for vitamin C
Red bell pepper Kiwi Brussel sprouts Strawberries Orange Brocolli Tomato juice
Vitamin C megadoses: consequences
- False positive urinalysis
- Drug interactions
- Oxidative stress: interaction with iron
- Kidney stones
What is the only form of vitamin E we can use
Alpha-Tocopherol
Vitamin E function
- Protects PUFAs in membrane lipids from oxidation
- Protects lungs, heart from oxidation and inflammation
- protects lipids in foods, to protect PUFA oils
What are the consequences of vitamin E deficiency and is it a primary or secondary deficiency ?
Secondary deficiency (cystic fibrosis)
- RBCs break-haemolysis
- WBCs break-immune function
- cataracts,arthritis,cancer,fibrocystic breast disease, CVD( LDL oxidation)
- Neurologic disfunction
Vitamin E toxicity
-interferes with anticlotting reactions-> that is why you need to stop to take vitamin E before the surgery
Is vitamin E toxicity widespread?
No, it is regulated by liver
RDA and UL for vitamin E
RDA- 15 micrograms/day
UL-1000 micrograms/day
Vitamin E in foods
PUFAs oil or foods containing PUFAs( nuts,friuts , veg)
Very susceptible to oxidation, needs to kept not in the light and heat
Vitamin E positive effects
- Cataract prevention
- Immune system function
- Cancer
- Neurological( Parkinson’s)
Other antioxidants
- metalloenzymes (Se,Mn,Zn,Fe)
- Glutathione-tripepeptide
- Phytochemicals
Classes of phytochemicals
- Polyphenols
- Resveratrol
- Lutein( tomatoes)
- Zeaxanthin( wine, grapes)
Foods rich in Se
Meats,milk,eggs, Brazil nuts
Increasing fruits and veg
decreases cancer, CVD,DM2,Obesity,vision loss, GI issues
What is phytochemical
Non-nutrient components of plants that are biologically active and believed to be protective against disease
What is the biggest source for phytochemicals we consume?
Coffee
Do we need to take supplements with antioxidants
Was not proved that it prevents mortality. the same is fir fish oil supplements
What are some concerns with supplementation?
Marketing
Sometimes costly and harmful to health
Physician should prescribe
Who controls supplementation package ?
Natural Heath Products Regulation
Pros for supplementation
- Correct deficiencies
- Improve nutritional status
- Decrease chronic disease risk
- Support increased needs- lifecycle, illness
- Vegan diets
Cons for supplementation
- Toxicity
- False sense of security
- Bioavailability
- Interactions
- Unknown ideal supplement
- Misinformation,claims
- Cost
Functional foods- definition and examples
-Foods that contain physiologically active compounds that provide health benefits beyond their nutritional value
Flax, tomatoes, blueberries, salmon,Dark chocolate, probiotics to yogurt
