3. WSV vs FSV
Water soluble vitamins Fat soluble vitamins
Function as Precursor
for co-enzymes & anti oxidants
Function as co-enzymes ,
harmones, and anti-oxidants
Excess amounts non toxic Excess amounts are toxic
These vitamins are not stored
except B12
These vitamins are stored
Body requires them frequently They are not required frequently
6. You should at least know
these…….
Specific co-enzyme of thiamine?
Dietary sources of thiamine?
Antimetabolites of thiamine?
RDA of thiamine
Types of beri beri & most complicated
form of beri beri
Metabolic reactions where TPP is
involved
Most commonly effected people?
Investigations and treatment?
7. OTHER NAMES OF
THIAMINE
Anuerine
Thiamin
Thio-vitamine
Anti beriberi factor
Sulphur containing vitamine
16. And also…..
Essential for transmission of nerve
impulse
TPP is required for synthesis of
Acetylcholine.
17. DUE TO LACK OF TPP………………
Increased plasma levels of pyruvate &
lactate due to low activity of PDH
complex
Accumilation of pentose sugars in
erythrocytes is due to decreased activity
of transketolase
Measurement of Transketolase activity is
common test used for the diagnosis of
B1 deficiency
19. Thiaminase
It is present in raw fish & seafood
Thiaminase destroys thiamine if it is
present in the diet
ANTIMETABOLITES
20. ABSORBTION:
Thiamine is carried by the portal blood to
the liver, present as free thiamine
STORAGE:
Usually stored as thiamine pyrophosphate
Mainly stored in skeletal muscle and also
present in significant amounts in liver,
heart, kidneys, erythrocytes and nervous
system
22. Food containing a high level of
thiaminase, including milled rice, raw
freshwater fish, raw shellfish, and
ferns
Lack of thiamine intake
Food high in anti-thiamine factor, such
as tea, coffee, and betel nuts
Processed food with a content high in
sulfite, which destroys thiamine
Alcoholic state
Starvation state
Causes of thiamine deficiency
25. Increased consumption states
Diets high in carbohydrate or
saturated fat intake
Pregnancy
Hyperthyroidism
Lactation
Fever - severe infection
Increased physical exercise
30. TREATMENT
Supplement thiamine, with dose based
on clinical manifestations
For mild polyneuropathy, thiamine 10
to 20 mg once/day is given for 2 wk.
For moderate or advanced
neuropathy, the dose is 20 to 30
mg/day; it should be continued for
several weeks after symptoms
disappear.
For edema and congestion due to
cardiovascular beriberi, thiamine 100
mg IV once/day is given for several
days.
31. The prognosis for beriberi is usually
good, unless patients have
established Korsakoff syndrome.
When patients have progressed to
this stage, the degree of damage is
only minimally reversible.
PROGNOSIS OF BERIBERI
33. You should at least know
these…….
Specific co-enzyme of Riboflavin?
Dietary sources of Riboflavin?
RDA of Riboflavin?
Riboflavin deficiency clinical
features?
Metabolic reactions where FAD and
FMN are involved?
Most commonly effected people?
Investigations and treatment?
34. OTTO HEINRICH
WARBURG
Isolated the "yellow
enzyme” of cellular
respiration.
He was nominated 47
times for Nobel prize
Known for his works in
cancers
35. AXEL THEORELL
Isolated riboflavin
Won Nobel prize in
1955 for his discovery
of oxidation enzymes
and its effects
36. PAUL KARRER
Determined the
structure of riboflavin
Best known for his
research in vitamins
Won Nobel prize in
1937
43. RIBOFLAVIN – ACTIVE
FORMS
Active forms of this vitamins(FMN &
FAD) are involved in…
Carbohydrate metabolism(PDH
&TCA)
Lipid metabolism
Protein metabolism
Purine metabolism
44. Active
forms of
riboflavin
are FMN
and FAD.
They act as
prosthetic
groups of
several
enzymes.
Catalyzes
oxidation-
reduction
reactions.
Growth, repair,
development
of body tissues
- healthy
skin, eyes and
tongue
52. TREATMENT
Riboflavin 2-5 mg PO daily with
incresed intake of B-complex vitamins
Parenteral riboflavin administered if
relief not obtained with oral intake.
53. References
Harper’s Biochemistry 25th Edition.
Fundamentals of Clinical Chemistry by Tietz.
Text Book of Medical Biochemistry-A R Aroor.
Text Book of Biochemistry- DM Vasudevan
Text Book of Biochemistry-MN Chatterjea
Text Book of Biochemistry-Dr.U.Satyanarana
Editor's Notes
In the United States today, the most significant dietary sources of riboflavin are meat and
meat products, including poultry and fish, and milk and dairy products, such as eggs and
cheese. In developing countries, plant sources contribute most of the dietary riboflavin
intake. Green vegetables, such as broccoli, collard greens, and turnip greens, are reasonably
good sources of riboflavin. Natural grain products tend to be relatively low in riboflavin,
but fortification and enrichment of grains and cereals has led to a great increase in
riboflavin intake from these food items.
The food sources of riboflavin are similar to those of other B vitamins. Therefore,
it is not surprising that if a given individual’s diet has inadequate amounts of riboflavin,
it will very likely be inadequate in other vitamins as well. A primary deficiency of dietary
riboflavin has wide implications for other vitamins, as flavin coenzymes are involved in
the metabolism of folic acid, pyridoxine, vitamin K, niacin, and vitamin D (27). from dietary sources. Appreciable amounts of riboflavin
may be lost with exposure to UV light, particularly during cooking and processing.
Prolonged storage of milk in clear bottles or containers may result in flavin degradation
(28). Fortunately, most milk is no longer sold in clear bottles. There has been some controversy
as to whether opaque plastic containers provide greater protection than do cartons,
particularly when milk is stored on a grocery shelf exposed to continuous fluorescent
lighting.
FMN is formed in intestine
FAD is formed in Liver
Flavin dependent enzymes (flavoproteins)
The major function of riboflavin, as noted above, is to serve as the precursor of the flavin
coenzymes, FMN and FAD, and of covalently bound flavins. These coenzymes are widely
distributed in intermediary metabolism and catalyze numerous oxidation–reduction reactions.
Because FAD is part of the respiratory chain, riboflavin is central to energy production.
Other major functions of riboflavin include drug and steroid metabolism, in
conjunction with the cytochrome P450 enzymes, and lipid metabolism. The redox functions
of flavin coenzymes include both one-electron transfers and two-electron transfers
from substrate to the flavin coenzyme (10).
Flavoproteins catalyze dehydrogenation reactions as well as hydroxylations, oxidative
decarboxylations, dioxygenations, and reductions of oxygen to hydrogen peroxide.
Thus, many different kinds of oxidative and reductive reactions are catalyzed by flavoproteins.
FMN Dependent enzymes:
FMN is a cofactor for L- amino acid oxidase.
NADH dehydrogenase of respiratory chain contains FMN
FAD Dependent enzymes:
D-amino oxidase
Succinate dehydrogenase
Aceyl coA dehydrogenase
Xanthine oxidase
Pyruvate dehydrogenase
A ketoglutarate dehydrogenase
Complex II of R chain