Transcript vitamin_b52c_b62cb72cb9b12_final_1.ppt

Vitamin B5
( Pantothenic Acid)
Vitamin B5 ( Pantothenic Acid)
It is a peptide composed of D-Pantoic acid and β-Alanine
and is found as calcium salt or as alcohol
(Pantothenol). The biologically active form of Vitamin
B5 is coenzyme A (CoA).
RDA: 7-10 mg (4 Years and over)
3-5 mg (less than 4 Years)
Principal Sources in Food
Principal dietary sources of vitamin B5 include:
Food
Serving size
mg
Calf liver
100 g
7.9
Pea nuts
100 g
2.6
Peas
100 g
2.1
Soybeans
100 g
1.9
Brown rice
100 g
1.7
lobster
100 g
1.7
Water melon
100 g
1.6
Egg
1, Avg size
0.9
Brewer’s Yeast
10 g
0.7
Pantothenic acid
Pantothenol
Functions of vitamin B5
Pantothenic acid is a part of CoA that acts as an intracellular
carrier for few carbons-groups and assists more than 100
pathways of intermediate metabolism including those of:
1. Synthesis of Sterols (Cholesterol and 7Dehydrocholesterol), Fatty acids, and Ketoacids such as Pyruvic acid.
2. Energy production
3. Synthesis of vitamins A and D.
4. Biosynthesis of protein and amino acid by assisting
the formation of leucine, arginine, and
methionine.
5. It is essential for the formation of hemoglobin
and electron-carrying cytochrome proteins of
the mitochondrial respiratory chain.
6.Biosynthesis of the neurotransmitter acetylcholine.
Symptoms of Vitamin B5 Deficiency
1.Paresthesias (It is a sensation of tingling,
pricking, or numbness of a person's skin)
and burning sensation in lower legs and
feets.
2. Joint and muscle aches
3. Fading of hair color
4. Anemia
5.Reduced immunity: impaired antibody response
6. Headache, depression, insomnia, and fatigue
Paresthesias
Muscle aches
Anemia
Insomnia
fatigue
People at high risk of Vitamin B5 Deficiency
Pantothenic acid is widely prevalent in foods,
subclinical deficiency only may occur, usually in
conjunction with other B-vitamin deficiencies in
case of:
Chronic illness
Heavy alcohol consumption
During hypocaloric dieting for weightloss.
Uses of Pantothenic acid in Prevention and Therapy
1.Microcytic anemia (through its role in
hemoglobin synthesis in conjunction with
iron supplementation).
2.Lupus
erythematosus:
Calcium
pantothenate, alone or in conjunction
with vitamin E can help in treatment of
Lupus
erythematosus
and
other
autoimmune disorders.
Lupus erythematosus
3.Tiredness and fatigue as those associated
with subclinical pantothenic acid.
4.Arthritis: Pantothenic acid deficiencies
are often found in patients with
osteoarthritis and rheumatoid arthritis. In
this case calcium pantothenate can be
effective.
Fatigue
Arthritis
5.Wound healing
operations.
after
trauma
or
6.Management
of
dyslipidemia
(abnormal amount of lipids e.g.
cholesterol and/or fat, in the blood).
7. Diabetic neuropathy (kidney disease
or damage that can occur in people
with diabetes).
9.
Dexapantothenol
(vitamin
B5
Formulation) is used topically in
treatment of burns and itching .
Wound healing
Vitamin B6
(Pyridoxine)
Vitamin B6 (Pyridoxine)
In 1934, a Hungarian physician, Paul Gyorgy
discovered a substance that was able to cure a skin
disease in rats (Dermititis acrodynia), this
substance he named vitamin B6.
Vitamin B6 converted in the body to its major active form:
pyridoxal-5-phosphate (PLP). The activation
requires adequate zinc and riboflavin.
Total body stores of vitamin B6 are low (only about 150
mg) hence a steady supply of vitamin B6 is essential
to avoid its deficiency.
Chemically it is a pyridine derivative.
RDA
1.2 – 1.4 mg (Adult)
0.6 mg (Infants less than 1 year)
2.2mg (During pregnancy and lactation)
Pyridoxol
Pyridoxal
Pyridoxamine
Pyridoxic Acid
DIFFERENT FORMS OF PYRIDOXINE
Sources of Vitamin B6
Potatoes
Banana
Calf liver
Lentils
Trout
Spinach
Functions of Vitamin B6
PLP is a coenzyme involved in more than 100 metabolic
reactions in the body including:
Protein synthesis through interconversion of amino acids.
Conversion of tryptophan to niacin.
It helps in maintaing blood glucose within a normal
range. When caloric intake is low, vitamin B6 help to
convert stored carbohydrate to glucose to maintain
normal blood sugar levels.
Lipid metabolism: It is important in synthesis of lipids of
myelin sheath surrounding nerves and also in
production of polyunsaturated fatty acids of cell
membranes.
It helps in hemoglobin synthesis and oxygen transport by
red blood cells.
Symptoms of Vitamin B6 Deficiency
Skin disorders: Dermatitis (skin inflammation), Stomatitis
(inflammation of the mucous lining of any of the
structures in the mouth), Glossitis (is inflammation or
infection of the tongue ), and Painful fissures and
cracks at the angles of the mouth and on the lips.
Abnormal brain-wave patterns, convulsions, and muscle
twitching.
Depression, irritability, anxiety, confusion, headache, and
insomnia.
Dermatitis
Stomatitis
Glossitis
Abnormal brainwave patterns
convulsion
Anemia and decreased antibody production
Possible increased risk of atherosclerosis due to
increased total cholesterol and LDLcholesterol in the blood, and reduced levels of
HDL-cholesterol.
Possible increased risk of calcium-oxalate kidney
stones.
Anemia
Atherosclerosis
Kidney stones.
People at high risk of vitamin B6 Deficiency
During rapid growth rate in childhood,
adolesence, and during lactation and
pregnancy; sharply increase in vitamin
B6 requirements.
High protein intakes increase vitamin B6
requirements.
Older people (little diets intake and less
efficient absorption).
Many common drugs (including oral
contraceptive pills and theophylline)
can reduce vitamin B6 stores.
People with chronic digestive problems
e.g. liver problems, diarrhea or irritable
bowel syndrome (poor vitamin
B6
absorption).
People with other chronic diseases,
including asthma, coronary heart
disease, diabetes, kidney failure,
rheumatoid arthritis, and cancer of
the breast, bladder, and lymph nodes.
Individuals with a poor quality diet or an
inadequate B6 intake.
Alcohol
consumption
also
promotes
the destruction and loss of vitamin B6
from the body.
Liver
Uses of Vitamin B6 in Prevention and Therapy
1.Treatment and prevention of deficiency and for
people at high risk of deficiency of Vitamin B6.
2.Skin disorders (eruptions, acne etc.).
3. Reduction of the severity and frequency of bronchial
asthma.
4.Atherosclerosis and cardio-vascular disease (It
reduces tendency for platelets to clump together,
lowers LDL-cholesterol and raises HDL
cholesterol.
5. In certain anemia, alone or with iron and vitamin A.
6. In Pregnancy-associated nausea and vomiting.
7. Premenstrual syndrome (It helps prevention of
mood swings, edema, acne, and
tenderness characteristic of PMS)
breast
8. Arthritis (it helps in reduction of swelling and
inflammation in the joints of the fingers).
9. Nerve disorders e.g. carpal tunnel syndrome
(occurs when the median nerve,
which runs from the forearm into the
palm of the hand, becomes pressed or
squeezed at the wrist) and other forms of
nerve inflammation and neuropathy.
Toxicity and side effects of vitamin B6
Very high doses (1000mg/day) for long time
peripheral nerve conditions: numbness in hands
and feet.
Doses of vitamin B6 not exceeding 500mg/day, or
higher doses for short periods (days to weeks), are
nontoxic in healthy persons.
Very high doses of vitamin B6 during lactation may
reduce milk production.
Vitamin B6 –Drug Interaction
Drug class
Examples
Mechanism of
interaction
Hydrazines
Iproniazid,
Isoniazid, hydralazine
React with pyridoxal and
PLP to form a hydrazone
Antibiotic
Cycloserine
Reacts with PLP to form
anoxime
L-DOPA
l-3,4dihydroxyphenylalanine
Reacts with PLP to form
tetrahydroquinoline
Derivatives
Chelator
Penicillamine
Reacts with PLP to form
thiazolidine
Alcohol
Ethanol
Increased catabolism of
PLP, low plasma levels
VITAMIN B7
Vitamin B7 (BIOTIN)
It is 2-Imidazolidinone tetrahydrothiophene-4- valeric acid.
Biotin is a cofactor required for
enzymes that are involved in
carboxylation
reactions
e.g.
acetyl-CoA carboxylase and
pyruvate carboxylase used in the
metabolism of carbohydrates,
lipids and amino acids
RDA: 100- 200 μg/day.
Principal Sources of Vitamin B7
Calf liver
Soybeans
Whole wheat
Milk & Egg
Oat meal
Mushrooms
Avocado
Functions of Vitamin B7
These functions are dependent on a biotin-containing
enzymes:
1.Glucose synthesis (The key initial step in
gluconeogenesis).
2.Fat metabolism (synthesis and breakdown of fatty
acids as well as the essential fatty acid metabolism such
as conversion of linoleic acid to various eicosanoids).
3.Amino acid metabolism (breakdown of amino acids,
such as threonine, isoleucine, and methionine, for use as
energy).
4.Cell division and growth (Biotin plays an important
role in DNA synthesis).
Biotin Deficiency
Biotin is found in numerous foods and also is
synthesized by intestinal bacteria and
deficiency of this vitamin is rare.
Deficiencies are generally seen only after long
antibiotic therapies which deplete the
intestinal flora or with anticonvulsant therapy,
and excessive consumption of raw eggs (a
biotin antagonist). The egg white protein,
avidin, prevents intestinal absorption of the
biotin.
BIOTIN DEFICIENCY SYMPTOMS
Extreme exhaustion
Grayish skin color
Depression
Drowsiness
Hair loss
Muscle pain
Loss of appetite
Uses of Vitamin B7 in Prevention and Therapy
Inherited syndromes of impaired biotin metabolism in
children.
Anticonvulsant therapy (Biotin supplements during chronic
anticonvulsant therapy reduce the risk of biotin
deficiency).
Diabetes (Biotin supplements help control blood glucose).
Dermatologic disorders e.g. Seborrheic dermatosis, acne, and
other forms of scaly skin rash can respond to biotin,
particularly when taken as part of a complete vitamin B
complex in conjunction with essential fatty acids
(omega-6 and omega-3 fatty acids).
Hair and nail disorders: People with dry, brittle hair and
fingernails may benefit from biotin.
VITAMIN B9
(FOLIC ACID)
RDA: 200 μg/day
Therapy: 400 – 800 μg/day
It is a water soluble conjugate of pteridine base, paminobenzoic
acid
and
glutamic
acid
or
pteroylmonoglutamic acid.
Most of folate absorbed
from the diet is converted to
the
active
form,
tetrahydrofolate
(THF)
coenzyme.
N5-methyl-THF is the
major storage form in the
body (~50% in liver): needs
vitamin B12 to be active.
Principal Sources in Food
Principal dietary sources of biotin
include:
Food
Serving size
μg
Calf liver
100 g
108
Soybeans
100 g
95
Brewer’s Yeast 10 g
92
Wheat germ
100 g
270
Egg
1, Avg size
100
Spinach
100 g
134
Broccoli
100 g
105
CHEMICAL STRUCTURE OF FOLIC ACID
FUNCTIONS OF VITAMIN B9
THF derivatives act as coenzymes for C1-transfer
(methyl, methylene, formyl or formimino group) during
biosynthetic reactions which helps the following
functions:
1. Production of RBCs through its role in creating
heme (the iron containing substance in
haemoglobin).
2. Production of WBCs.
3. Protein metabolism. It plays a central role in the
interconversion of amino acids such as glycine, serine
and methionine and the synthesis of structural and
functional proteins.
4. Production of nucleotides (ATP, GTP, and d
TMP) and thus nucleic acids: DNA and RNA
which are essential for growing and dividing
cells. Therefore, cells that rapidly turn over and
are replaced, such as blood cells and cells lining
the digestive tract, are particularly dependent on
THF.
5. Proper formation of the brain, spinal cord,
and nerve cells (CNS) in the embryo. Closure of
the neural tube in the fetus (in the 28th day of
pregnancy) cannot be completed without
Vitamin B9.
Major Symptoms of Vitamin B9 Deficiency
1. The most pronounced effect of folate deficiency on
cellular processes is upon DNA synthesis (due to
an impairment in d TMP synthesis)
arrest of
cell cycle of rapidly proliferating cells,
particularly, the RBCs
resulted in occurrence
of megaloblastic anemia as for vitamin B12
deficiency (characterized by abnormally large
immature and dysfunctional erythrocytes) which
causes fatigue, weakness, shortness of breath,
decreased ability to concentrate.
2. Impairments in white blood cell development
and leukopenia
reduce immune responses
to infection and/or cancer.
3. Impaired cell growth in the digestive tract,
inflammation of tissues in the mouth, stomach, and
intestine reduced absorption of nutrients.
4. Impaired fetal growth and development, birth defects
such as Neural Tube Defects (NTDs) e.g. Spina bifida.
Megaloblastic anemia
Leucopenia
Neural Tube Defects e.g. Spina Bifida
(SB) SB occurs when two sides of the
spine fail to close and protect spinal cord
People at High Risk of Vitamin B9 Deficiency
1. People who depend on processed food and neglect
whole grains and vegetables.
2. Smoking.
3. Many chronic diseases and health status such as
psoriasis, anemia, infections, cancer, fever, trauma,
surgery, or burns sharply increase folate requirements.
4. Liver disease interferes with folate metabolism and
increases excretion.
5. Rapid growth childhood, and adolescence.
6. Pregnancy.
7. Heavy alcohol consumption interferes with absorption,
impairs conversion to THF, and increases excretion.
8. Deficiency of ascorbic acid.
9. Deficiency of vitamin B12 impairs folate metabolism
and produces signs of folate deficiency.
Uses of Folic Acid in Prevention and Therapy
1. Prophylaxis from birth defects:
Supplemental folate (400μg/day) days before
conception and during early pregnancy reduces the
risk of birth defects, particularly neural tube defects,
cleft lip and palate.
2. Atherosclerosis:
Folate help preventing atherosclerosis (heart attack,
and peripheral vascular disease) in people with
elevated homocysteine (THF with Vitamin B12
detoxify homocysteine to methionine).
3. Enhance immunity in case of infections.
4. Cancer:
Folate supplements may also reduce the risk of
colon cancer in people with inflammatory bowel
diseases. Folate + vitamin A can reduce the risk of
cervical dysplasia (abnormal changes in the cells
on the surface of the cervix) progressing to
cervical cancer. Folate + vitamin B12 can
reduce dysplasia in the lungs of smokers and
reduce the risk of lung cancer.
4. Psychiatric/nervous disorders:
Symptoms of dementia in elderly people may be
improved by folic acid supplementation. Folate
can be adjunctive therapy with lithium in the
treatment of manic- depressive illness.
Folic Acid – Drug Interactions
Drugs reduce folate level e.g.
Aspirin
oral contraceptive pills
Antacids
Anticonvulsant
antibiotics.
Folic acid antagonists e.g.
Methotrexate
VITAMIN B12
(Cobalamin, Antipernicious anemia factor)
Vitamin B12
1. Vitamin B12 is a family of related compounds
containing a cobalt atom (cobalamins).
2. The two dietary forms of vitamin B12 are available
and they are known as methylcobalamin (meth ylB12) and 5- deoxyadenosylcobalamin (coenzymeB12).
3. Synthetic forms of vitamin B12 are known as
hydroxy-cobalamin and cyanocobalamin (not occur
naturally in foods).
4. Structure of B12 is very complicated and based on a
corrin ring, similar to porphyrin ring found in heme,
chlorophyll, and cytochrome.
A
B
D
C
Vitamin B12
5. The central metal ion is cobalt (Co) which
coordinates with nitrogens of corrin ring and that
of dimethylbenzimidazole group.
6. The sixth coordination can be : CN- (in
Cyanocobolamin), HO- (in Hydroxycobalamin),
CH3
(in
Methylcobalamin,
Me-B12),
deoxyadenosyl group (Adenosylcobalamin, AdoB12 = coenzyme-B12).
7. Very small amounts of vitamin B12 are stored in
our bodies, about 90% of which (2–5 mg) is
stored in the liver and is sufficient for 2 years.
Sources of vitamin B12
The intestinal flora produces the vitamin required for man and
animals. Vitamin B12 can be obtained from animal diet only.
Principal Sources in Food
Principal dietary sources of vitamin
B12 include:
Food
Serving size
μg
Calf liver
100 g
60
Egg
1, Avg size
1
Beef
100 g
2
Milk
1, large glass
0.4
Hard Cheese 30 g
0.6
Mussels
100 g
8
Required Daily
Amount (RDA)
Age
1-3
4-8
9 – 13
14 – 18
>18
μg/day
0.9
1.2
1.8
2.4
2.4
Absorption of vitamin B12
 Vitamin B12 in food is bound to protein.
 HCl of the stomach releases the free vitamin B12.
 Once released, vitamin B12 combines with
glycoprotein intrinsic factor (IF) secreted by the
parietal cells of stomach to form a complex which can
be absorbed from ileum.
Functions of Vitamin B12
1. Essential with folic acid in RBCs maturation (it
protects against Pernicious anemia).
2. Folate metabolism. Vitamin B12 is vital in
activation of folate to the active THF. In vitamin B12
deficiency, tissue stores of folate are “trapped” as
inactive methylated forms, and a functional folate
deficiency results.
3. Protein metabolism: Act as coenzyme with THF in
the synthesis of methionine from homocysteine.
4. It is vital in fat metabolism.
5. Helps maintain the antioxidant status by
maintaining glutathione in the reduced form.
6. Nervous system (It is vital in synthesis of
myelin sheath of neurons).
7. Cell replication. It is essential with THF in
synthesis of nucleic acids.
People at High Risk of Vitamin B12 Deficiency
1. Eldery people: Gastric secretion and intrinsic factor is
diminished. Both are required for optimum vitamin B12
absorption.
2. People suffering from chronic gastritis with atrophy of
the parietal cells that produce intrinsic factor.
3. Intestinal diseases e.g. chronic enteritis with diarrhea
reduce absorption of vitamin B12.
4. Liver disease impair vitamin B12 status (as the liver is the
site of vitamin B12 storage and the site of production of
specific transport proteins).
5. Strict vegetarian diets (devoid of animal products).
6. Cigarette smoking impairs vitamin B12 status.
Major Symptoms of Vitamin B12 Deficiency
1. Pernicious Anemia: It is a case of
megaloblastic anemia caused by atrophic
gastritis and parietal cell loss and
characterized by neuropathy: ease fatigue,
weakness, shortness of breath, decreased
ability to concentrate, and peripheral nerve
damage.
2. Neurological changes such as numbness and
tingling in the hands and feet (due to
diminished myelination).
3. Difficulty
depression,
memory.
in
maintaining
balance,
confusion, dementia, poor
4. Reduced platelet production (increase risk of
abnormal bleeding).
5. Impaired white blood cell development
reduces immune responses to infection and/or
cancer.
6. Impaired cell replication leads to atrophy and
inflammation of mucous membranes in the
mouth, tongue and GIT, reduced absorption of
nutrients, constipation, anorexia, and weight
loss.
Uses of Vitamin B12 in Prevention and Therapy
1. Treat and prevent deficiency conditions and pernicious
anemia (a condition in which the body can't make enough
healthy red blood cells).
2. In combination with folate to treat megaloblastic anemia.
3. Treatment of psychiatric/nervous disorders e.g. dementia
and memory loss, particularly in the elderly people.
4. It is helpful with folate in prevention and therapy of
atherosclerosis associated with high levels of blood
homocysteine.
5. It is helpful with folate to reduce smoking-induced
precancerous cells in the lungs
reducing risk of lung
cancer.
6. Reduction of peripheral nerve disorders e.g. neuropathy in
diabetics, trigeminal neuralgias and traumatic
nerve
injuries.
7. Large doses (5- 10 g IV) of Hydroxycobalamin used in
cyanide poisoning where it combine with cyanide ion to
form harmless Cyanocobalamin.
In pernicious anemia, vitamin B12 should be given as
IM injection (100 to 1000 μg of cyanocobalamin for 5
days followed by 100 to 1000 μg each month) till
correction of blood picture.
Vitamin B12 – Drug Interaction
Some Drugs interfere with its absorption such as:
Alcohol
p-aminosalicylic acid
Colchicine
Neomycin
Cholestyramine
Anticonvulsants (Phenytoin)
Metformin
H2
blockers include cimetidine, proton pump
inhibitors e.g. omeprazole reduce secretion of
gastric acid and pepsin
reduce isolation and
absorption of protein-bound (dietary) vitamin
B12.
THANX