Lecture 23: Vitamins

Question 1

Fat soluble vitamins are taken with lipids. What are some fat soluble vitamins?

Answer 1

Vitamin A
Vitamin D
Vitamin E
Vitamin K

Question 2

Vitamin A

• Function
• Source
• Consequences of deficiency

Answer 2

Function: Vision with rhodopsin
Source: From animals and PROVITAMIN A carotenoid from red and yellow plants
= liver, carrot, leafy veges
Deficiency: Blindness, infectious disease and death

Question 3

How does vitamin A affect sight?

What happens when you are vitamin A deficient ?

Answer 3

• Vitamin A comes in Cis form which is able to fit into the protein opsin to form rhodopsin
• When a photo of light hits the rhodopsin, vitamin A changes into trans form
  This confirmation change triggers nerve impulse
  Lack of vit A = Xerophthalmia ‘dry eyes/tears’
  If overdosed during pregnancy can lead to spontaneous abortion or fetal abnormalities

Question 4

Vitamin D

• Function
• Source
• Consequences of deficiency

Answer 4

Function: Maintains calcium balance in body
Source: synthesised at skin in exposure to UV - and oil fish, egg yolk
Deficiency: Softening and weakening of bones = RICKETS

Question 5

Vitamin E

• Function
• Source
• Consequences of deficiency

Answer 5

Function: Membrane integrity by preventing oxidation of unsaturated fatty acids
Source: Vege oils and concentrated in animal fat
Deficiency: Is rare = neuropathy

Question 6

Vitamin K

• Function
• Source
• Consequences of deficiency

Answer 6

Function: Required for normal blood coagulation
Source: Green leafy veges
Deficiency: Haemorrhage - VKDB uncommon spontaneous bleeding or bruising
- Offered to babies at birth
- Offered best by intermuscular dose

Question 7

Folate B9

• Function
• Source
• Consequences of deficiency
• Dose

Answer 7

Function: Neural tube development and DNA replication
Source: Fortified veggies and food
- Breakfast cereals may be fortified
Deficiency: neural tube defects ——-> spinaldefia and anaemia
Dose: 800Ug folic acid per day before coming pregnant

Question 8

How can folate levels be increased?

What are the 3 ways?

Answer 8

1. Increasing supplement use
   - Give correct dose to right people; however half of the pregnancies are unplanned so its too late to take folate
2. Voluntary fortification
   - Women can buy fortified foods - price levels are discriminating and levels of folate are too low
3. Mandatory fortification
   - Litte discrimination, reaches most women and it works in the background
   - levels of folate are still too low so women do not receive 800ug