Vitamin Deficiencies

Question 1

What are the fat soluble vitamins and what is their significance?

Answer 1

A,D,E,K—these are the fat soluble vitamins. They are more readily stored in the body, but in the case of a fat malabsorptive disorder, they may be poorly absorbed so they’ll need to be supplemented

Question 2

Vitamin A is the generic name for a group of related fat-soluble compounds that include retinol, retinal, and retinoic acid.

Answer 2

ok

Question 3

What are important dietary sources of vitamin A

Answer 3

Liver, fish, eggs, milk, butter

Question 4

Yellow and leafy green vegetables such as carrots, squash, and spinach supply large amounts of carotenoids

Answer 4

, many of which are pro-vitamins that are metabolizede to active vitamin A in the body

Question 5

WHat is the most important carotenoid

Answer 5

Beta-carotene

Question 6

How is retinol carried through the blood and where is it stored?

Answer 6

Carried through the blood by chylomicrons. Taken up by the liver via the apolipoprotein E receptor. more than 90% is stored in the liver via the perisinusoidal stellate cells (Ito).

Question 7

What are the functions of vit. A/ retinol?

Answer 7

• maintaining normal vision in reduced light
• potentiating the differentiation of specialized epithelial cells, mainly mucus secreting cells
• Enhancing immunity to infections (especially measles)

Question 8

The visual process involves four forms of Vitamin A containing pigments

Answer 8

Rhodopsin- the most light sensitive and therefore very important in dim light conditions

Three iodopsins that are responsive to a specific color in bright light.

Question 9

What type of malabsorption syndromes may you see Vitamin A deficiency in?

Answer 9

Celiac disease, crohn’s disease, colitis

Question 10

The role of Vitamin A on epithelial cell differentiation can best be seen in the eye.

Answer 10

Xeroppthalmia (dry eye) due to the normal lacrimal and mucus secreting epithelium being replaced by keratinized epithelium.

Build-up of keratin debris called Bitot spots

Question 11

Vitamin A deficiency and the respiratory tract

Answer 11

Leads to squamous metaplasia, thus loss of the mucociliary epithelium of the airways predisposes patients to pulmonary infections

Question 12

Acute vitamin A toxicity looks ike

Answer 12

headache, dizziness, vomitting, stupor, blurred vision

Question 13

Chronic vit A toxicity

Answer 13

Weight loss, anorexia,, nausea, vomitting