1. Assignment on Vitamin A:
1. Invention of Vitamin A
2. Chemistry of Vitamin A
3. Vitamin- A synthesis
Vitamin- A synthesis of novel Vitamin A intermediates from beta-ionone is described as well
as a conversion of the intermediates to Vitamin A. The length of the conjugated aliphatic
side chain of beta-ionone is increased while still ultimately obtaining the desired trans form
of Vitamin A. In general, beta-ionone is ethynylated to ethynyl-beta-ionol, the hydroxyl of
which is etherified to form an ethynyl-terminated, alkoxy-substituted, beta-ionol intermediate.
The intermediate is coupled through its copper derivative with a compound like chloro-
isopentenyl acetate to produce a C20 skeleton. By semi-hydrogenation, the acetylenic bond
on the C20 skeleton is converted to an ethylenic bond, and by hydrolysis the terminal ester
moiety is converted to a hydroxyl group. Treatment with a strong base removes the alkoxy
group to produce Vitamin A.
4. Stability of Vitamin A

2. Absorption of Vitamin A The level of vitamin A in the plasma or serum is a reflection of the quantities
of vitamin A and carotene ingested and absorbed by the intestine (carotene is converted to vitamin A by
intestine absorptive cells and hepatocytes).
5. Blood level of Vitamin A
6. Storage of Vitamin A
7. Excretion of Vitamin A
8. Source of Vitamin A
Sources: whole milk, carotene, animal body oils (cod fish and tuna), legume forages and
can be synthetically produced.
9. Requirement of Vitamin A
10. Deficiencysign of Vitamin A
Deficiency signs: retarded growth in the young, the development of a peculiar condition
around the eyes known as Xerophthalmia, night blindness and reproductive disorders.
11. Treatment of Vitamin A
12. Toxicity of Vitamin A
Vitamin A in excess can be toxic. In particular, chronic vitamin A intoxication is a concern in normal
adults who ingest >15 mg per day, and in children who ingest >6 mg per day of vitamin A over a
period of several months. Manifestations are various and include dry skin, cheilosis, glossitis,
vomiting, alopecia, bone demineralization and pain, hypercalcemia, lymph node enlargement,
hyperlipidemia, amenorrhea, and features of pseudotumor cerebri with increased intracranial
pressure and papilledema. Liver fibrosis with portal hypertension and bone demineralization may also
result. Congenital malformations, like spontaneous abortions, craniofacial abnormalities, and valvular
heart disease have been described in pregnant women taking vitamin A in excess. Consequently, in
pregnancy, the daily dose of vitamin A should not exceed 3 mg.
Assignment Submission date is 08/11/2013 or Before Exam