Functional role/s: A fat soluble antioxidant, main action is to stop the chain of free radicals/producing more free radicals

RDI or AI: AI (α-tocopherol Equiv.): men: 10 mg /d; women: 7 mg/d.

Upper level: 300 mg/day

Stability: Sensitive to heat and oxygen, therefore fresh- food sources preferable.

Primary deficiency due to inadequate intake is rare. 
Erythrocytehaemolysis(Haemolyticanaemia): 

– Occurs in premature infants. – Can be treated with vitamin E. 

• Symptoms: 

– Loss of muscle coordination and reflexes.
 – Impaired vision and speech, nerve damage. 

Toxicity symptoms:
Rare and the least toxic of the fat-soluble vitamins. 
 Extremely high doses may augment the effects of anticlotting medication haemorrhage. 
 Note that the upper limit is >30 times the RDI (300 mg/day). 

Functional role/s:
Roles:

Influences over 500 genes and main roles include:

-          Promoting vision

-          Participating in protein synthesis and cell differentiation

-          Maintaining health of epithelial tissues, mucous membranes and skin

-          Supporting reproduction and growth

-          Assists with bone and tooth growth

-          Assists with immunity

 

Each vitamin A has specific roles:

-          Retinol supports reproduction and is major transport and storage of Vitamin A

-          Retinal promotes vision and assists with conversion of retinol to retinoic acid

-          Retinoic acid regulates cell differentiation, growth and embryonic development

RDI or AI: 
 

Men = 900ug per day

Women = 700ug per day

Upper level for adults: 3000 μg RE/day. 

•Toxicity is often associated with abuse of supplements. 

• Status depends on stores (90% in liver) and protein status 

• (Retinol binding protein transports Vit A in the blood)

Vitamin A is relatively stable in alkaline solutions. Vitamin A is sensitive to atmospheric oxygen with the alcohol form being less stable than the esters. The decomposition is catalysed by the presence of trace minerals.

Deficiency disease = 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.

 

Toxicity disease = 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 (not Betacarotene) from animal foods, fortified foods or supplements

- Leafy green vegetables. 

- Wheat germ. 

- Wholegrain foods. 

- Liver and egg yolks. 

- Nuts and seeds.

Function(s)/Role(s): As an anti-oxidant;   scavenging loose electrons—so-called “free radicals”—that can damage cells.  also enhances immune function and prevents clots from forming in heart arteries 
Adequate Intake:  men: 10 mg/day; women: 7 mg/day.
Upper Level: 300 mg/day
Stability:  Sensitive to heat and oxygen
Deficiency: Erythrocytehaemolysis (Haemolyticanaemia): 

– Occurs in premature infants. – Can be treated with vitamin E. 

Symptoms: 

– Loss of muscle coordination and reflexes.
 – Impaired vision and speech, nerve damage. 

Toxicity*:  Rare and the least toxic of the fat-soluble vitamins.
 Extremely high doses may augment the effects of anti-clotting medication hemorrhage.
*Note that the upper limit is >30 times the RDI (300 mg/day).  

- Nuts and seeds
Function and Roles:
- A fat soluble antioxidant
stops the chain of free radicals/producing more free radicals
Stability: Sensitive to heat and oxygen, therefore fresh-food sources preferable
Adequate Intake:
- Men: 10 mg/day
- Women: 7 mg/day
- Upper level: 300 mg/day
Deficiency:
- Erythrocyte haemolysis (haemolytic anaemia):
- Loss of muscle coordination and reflexs
- Imapured vision and speeach (nerve damage)
Toxicity:
- Rare and least toxic of fat soluble 
High doses = augment effects of anticolotting medication 

FUNCTIONAL ROLES:
-maintaining vision
-promoting growth development
-protecting epithelium

RDI
 900 mcg for men
 700 mcg per day women

UPPER LEVEL
3,000 mcg

STABILITY