Which are vitamins are fat soluable?
Vitamin A, D, E and K
- they are absorbed in the intestine along with dietary lipids
Explain the role of Vitamin A
What are the food sources
What are the symptoms of deficiency
Important for eye vision (low light conditions) and important for cell turn over
Process: vitamin A - retinal + opsin - rhodopsin - activate to send to brain signal
- cis retinal is important in low light
Sources:
Animals: beef, liver, diary, chicken, egg yolk, and milk
Plants: spinach, carrots, mango, apricots, pumpkin, cantaloupe, broccoli, sweet potatoes
Symptoms of deficiency: xerophtalmia (dry eyes), impaired growth, reproductive function
Symptoms of toxicity: fatigue, bone and joint pain, nausea, liver damage, blurred vision, hair loss and skin disorders
- too much retinoids acid promote cell turnover over but remove good cells too
Explain the role of Vitamin D
What are the two sources of vitamin D
Explain the pathway of vitamin d formation
What are the symptoms of deficiency and toxicity
Derived from CHO and essential to maintain bone health, calcium balance and body function
- UV light to activate the production of vitamin d
- Vitamin D2 from plants and Vitamin D3 from animals enter the bloodstream but are not activated
Pathway: UV light - 7 dehydrocholesterol - vitamin d - liver to convert 25 hydro vitamin d (not active) - kidney - convert to calcitrol (active form)
- if Calcium levels are low then Ca+ is released from the bones (last resource)
Sources: egg yokes, fatty fish, dairy
- fat must be taken along with vitamin d supplement to absorb and transport into the blood
Symptoms of deficiency: rickets (weak bones and legs are bent) and osteomalacia/ osteoporosis (soft bend in bones as they lose Ca+)
Symptoms of toxicity: hypercalcemia
What is the role of Vitamin E
