Week 11: Fat Soluble Vitamins Flashcards
(29 cards)
What is vitamins a’s, precursor
Also known as retinol, retinal, retinoic acid.
- Beta(β)-Carotene is the precursor (also termed provitamin)
- Not all β-Carotene converted to Vitamin A
- Absorption of β -Carotene less efficient than that of Vitamin
A
- 6µg β-Carotene equivalent to 1µg Vitamin
Describe vit a 3 roles
- Vision:
-> helps maintain a crystal clear cornea.
-> Participates in conversion of light energy into nerve impulses in the retina - healthy epithelial cells:
-> Vit A participates in protein
synthesis and cell differentiation- Epithelial tissue
-> Skin – Vit A helps protect it against damage from sunlight.
-> Mucous membrane integrity - It helps differentiate epithelial cells and goblet cells - Growth
-> Men: Retinol participates in sperm
development.
*-> Women: Vitamin A supports normal fetal
development during pregnancy.
-> Children lacking vitamin A fail to grow
What is vit a rdi for men and female
RDI men: 900 μg RE/day; women: 700 μg RE/day
What is the vit a UL
3000 μg RE/day.
What is the deficiendy disease due to vit a
Hypovitaminosis A
– Impaired immunity and susceptibility to infectious diseases.
– Night blindness.
– Blindness (Xerophthalmia).
– Keratinisation – changes in epithelial cells results in
keratinisation, rough, dry and scaly skin.
What is the toxicity disease due to vit a
Hypervitaminosis A.
– Chronic toxicity symptoms = liver
abnormalities, weakened bones
contributing to osteoporosis, cause
birth defects
– Acute toxicity symptoms = blurred
vision, nausea, vomiting, vertigo,
headaches and pressure in the skull.
– Vitamin A toxicity – can occur with
concentrated amounts of the
preformed vitamin A
What are 3 common food sources of vit a
beef live,r sweet potato, carrots
Can vit d be prof by body
- Body can synthesis it, with help from the sun, from
- a precursor that the body makes from cholesterol.
What is the vit d Ai and UL
- AI 5 μg/day for adults 19–50 years old.
- UL: 80μg/day
What is vit d’s main role and 3 ways how
- maintain blood levels of Ca and P
–> enhancing GIT absorption
–> enhances reabsorption from kidneys
–> enhances mobilisation from bones into the blood
What are 3 factors that contirbute to vit d deficiency
- Dark skin
– Breastfeeding infants by Vit D deficient mothers
– Lack of sunlight
What are 3 vit d deficiency disorders
- Rickets in children.
- Osteomalacia and Osteoporosis in adults.
3 reasons why elderrs are at a higher risk of vit d deficiency
- Skin, liver and kidneys lose capacity to make & activate Vit D
- Older people typically drink little or no milk
- Spend more time indoors and often wear protective clothing
Who are 4 other groups of people who are at risk of vit d deficiencty
- Dark skinned people of either sex, particularly migrants & those wearing modest dress
- People with a disability or chronic disease
- Fair skinned people and those at risk of skin cancer who avoid sun exposure
- People working in a closed environment
What are 3 health benefits of vit d
Diabetes.
– Cardiovascular disease., obesity
What leads to vit d toxicity and what disease?
- Hypervitaminosis D
– Vitamin D from sunlight and food is not likely to cause toxicity
– High-dose supplements may cause toxicity.
What are 3 common symptoms of vit d toxicity
- Elevated blood calcium
– Calcification of soft tissues (blood vessels, kidneys, heart, lungs and tissues around joints).
– Frequent urination.
What are 3 sources of vit d
- can be sysntehsised in body with sun
- Fortified milk, butter and margarine.
– Egg yolks and liver.
– Fatty fish (erg. Salmon, herring, mackeral) and their oils. - Without adequate sunshine, fortification or supplements, vegans may not meet Vit D needs.
What is the main role of vit e
A fat soluble antioxidant, main action is to stop the chain of free radicals/producing more free radicals
What is the AI for men and women and the UL
- men: 10 mg /d; women: 7 mg/d.
- Upper Level: 300 mg/day
Describe how to minimise vit e losses
Sensitive to heat and oxygen, therefore fresh- food sources preferable.
What are vit e deficiency disease adn 2 symptoms of defiency
- defifiency rare.
- Erythrocyte haemolysis (Haemolyticanaemia):
–> Occurs in premature infants. – Can be treated with vitamin E.
– Loss of muscle coordination and reflexes.
– Impaired vision and speech, nerve damage.
Is there toxicity symptoms of vit e
- Rare and the least toxic of the fat-soluble vitamins.
What are 3 common food sources of vit e
- Polyunsaturated plant oils such as margarine, salad dressings and shortenings.
– Leafy green vegetables.
– Wheat germ+ Wholegrain foods.
