Vitamins

Question 1

What are the Water-Soluble Vitamins and fat soluable vitamins

Answer 1

Water-Soluble Vitamins:
- Vit C
- Thiamine (B1)
-Riboflavin (B2)
-Niacin (B3)
- B5
-Pyridoxine (B6)
- Cobalamin (B12)
- Folate
-Biotin

Fat soluable
ADEK

Question 2

Water soluable vs fat solubale
absorption route
Transport
Storage
Excretion
Toxicity
Requirements

Answer 2

Water:
absorption route: directly into blood
Transport: Freely travel
Storage: Ciruclate in water filled parts of body
Excretion: Kidneys
Toxicity: Possible with supplements
Requirements: needed in frequent doses (1-3 days)

Fat
absorption route: Into lymph then blood
Transport: protein carriers
Storage: Cells with fat
Excretion: less readily excretes
Toxicity: likely with supplment intake
Requirements: Needed in periodic doses

Question 3

Most of vitamin abs occurs where

Answer 3

Duodenum and Jejunum and ileum

Question 4

Factors affecting bioavailability

Answer 4

• Efficiency of digestion/transit time
• Previous nutrient intake and nutritional status
• Other foods consumed simultaneously
• Food preparation method
• Source of the nutrient – synthetic or natural
• Health status

Question 5

Thiamine sources

Answer 5

– Whole grain, fortified, or
enriched grain products
– Moderate amounts in all
nutritious food
– Pork

Question 6

Thiamine Deficiency
2 examples of diseases

Answer 6

Wet “beriberi” - Cardiac
* Oedema
* Tachycardia
* Heart Failure

Dry “beriberi” - Neurological
*Peripheral
neuropathy
* Wasting

Question 7

Thiamine deficiency causes in developed countries

Answer 7

alcoholism

Question 8

Folate
-chemically what is it

Answer 8

Ring structure and glutamate

Question 9

Folate deficiency
- examples of diseases

Answer 9

• Macrocytic (Megaloblastic) anaemia
• Neural tube defects (NTDs) during foetal developments e.g. spinal bifida, anencephaly

Question 10

Causes of folate deficiency

Answer 10

• Low dietary intake
• Increased need
• Reduced intestinal absorption
• Anticonvulsant drugs; some lipid lowering drugs
• Folate antagonists -Methotrexate
• High alcohol intake – leading to decreased absorption,
  increased catabolism, often accompanied by poor diet.
• Pregnancy – due to increased folate requirement

Question 11

Vitamin D
- activation process

Answer 11

7-dehydrocholestrol to previtamin D through UV

Previtamin D3 to Vit D3 (inactive form) through foods

In the liver; inactive D3 goes to 25-hyroxy vit D3 through hydroxylation

In the kidneys, 25-hyroxy vit D3 to 1, 25-hyroxy vit D3 through hydroxylation

Question 12

Food Sources of Vitamin D

Answer 12

salmon, cod liver, eggs, mushrooms, beef liver, milk

Question 13

Role of 25-hyroxy vit D3 vs 1, 25-hyroxy vit D3

Answer 13

25-hyroxy vit D3:
Reg of cell growth (cancer prevention)
Reg of immune function

1, 25-hyroxy vit D3
Calcium, muscle and bone health
Reg Blood pressure and insulin production

Question 14

Vitamin D Deficiency diseases (2)

Answer 14

• Rickets – children
• Osteomalacia - adults

Question 15

Causes of low Vitamin D :

Answer 15

• housebound with limited exposure to direct sunlight
• dark-coloured skin
• completely covered skin with clothing or veils
• sun avoidance
• malabsorption
• renal disease