2. ❖ Organic molecules, essential for the normal
growth and development, required in tiny amounts
Introduction to Vitamins
VITAL + AMINES = VITAMIN
❖ Cannot be synthesized in sufficient quantities by
mammalian cells; must be supplied in the diet
Vitamin C – vitamin for human
Vitamin K, H – synthesized by gut flora
Vitamin A - from precursor beta carotene
3. FUNCTIONS
• Regulate metabolism, help convert lipids and saccharides
into energy (B-complex)
• Hormones (vitamin D)
• Antioxidants (vitamin E, C)
• Regulators of cell and tissue growth and differentiation
(vitamin A)
• Coenzyme precursors (B-complex)
4. AVITAMINOSIS - chronic or long-term vitamin lack (beri-beri,
scurvy, rickets and pellagra)
HYPOVITAMINOSIS - any of several diseases caused by
deficiency of one or more vitamins
HYPERVITAMINOSIS – the condition resulting from the
chronic excessive intake of vitamins (vitamin supplements)
side effects – nausea, diarrhea, vomiting
5. Avitaminoses
▪ Vitamin A deficiency causes xerophthalmia or night blindness
▪ Thiamine (B1) deficiency causes beri-beri
▪ Niacin (B3) deficiency causes pellagra
▪ Vitamin B12 deficiency leads to megaloblastic anemia
▪ Vitamin C deficiency leads to scurvy
▪ Vitamin D deficiency causes rickets
▪ Vitamin K deficiency causes impaired coagulation
▪ Rare in developed world - fortification
6. ANTIVITAMINS
H2N C
O
OH
Paraaminobenzoic acid (PABA)
H2N S
O
NH2
O
Sulphonamide
Sulphonamides – prevent bacterial multiplication, without toxicity to the human tissues
• substances that destroy or inhibit the metabolic
action of a vitamin
Classification:
1. Enzymes decomposing vitamins (thiaminase, ascorbase)
2. Compounds forming nonactive complexes with vitamins (avidin)
3. Compounds structurally similar to vitamins
(sulphonamides)
7. Water Soluble Vitamins Fat Soluble Vitamins
Thiamine (B1)
Riboflavin (B2)
Niacin (B3)
Panthotenic acid (B5)
Pyridoxin (B6)
Biotin (B7 ) – vitamin H
Folic acid (B9)
Cobalamin (B12)
Bioflavonoids (P)
Ascorbic acid (vit. C)
Vitamin A - Retinol
Vitamin D - Calciferol
Vitamin E - Tocoferol
Vitamin K – Quinons
Vitamin F
Water soluble vitamins Fat soluble vitamins
8. Vitamins soluble in water
➢ directly absorbed from intestine into blood
➢ hypervitaminosis – vitamins excreted from the body
Vitamins soluble in fat
➢ require correct function of the liver and gall bladder
➢ hypervitaminosis – toxic effect
9. Its provitamin - -carotene - (red, orange pigments in plants and fruits)
- Antioxidant
-CAROTENE
VITAMIN A (R E T I N O L)
Structure: tetraterpenoid containing -ionone ring with an unsaturated
side chain
-, - a - provitamin A
13. Functions of vitamin A
❖ Vision – retinal is a structural part of rhodopsin (visual purple) –
light sensitive pigment in retina
❖ Bone remodeling – function of osteoblasts and osteoclasts
depend on it.
❖ Reproduction – sperm production, menstrual period
❖ Resistance to infectious disease – deficiency leads to
increased frequency and severity of disease
15. HYPOVITAMINOSIS A
➢ Night blindness – mild deficiency of vitamin A – inability to
produce sufficient amount of rhodopsin (lack of retinal)
➢ Large deficiency of vit. A – xeroftalmia – keratinisation of the eye
tissue (today in Africa, Asia)
➢ Dry skin, frequent infections, decreased synthesis of thyroid
hormones
16. HYPERVITAMINOSIS
β-carotene supplements (high doses)
• Skin discoloration
• Lung cancer / smokers /
Retinal
• Birth defects
• Liver problems
• Reduced bone mineral density that may result in osteoporosis
• Hair loss
• Excessive skin dryness/peeling
• Death
Signs of acute toxicity – nausea, vomiting, headache, dizziness, blurred vision, loss
of muscular coordination
17. SOURCES
The body stores both retinol and beta-carotene in the liver,
drawing on this store whenever more vitamin A is needed
β-carotene - carrot, green leafy vegetables – spinach, kale,
sweet potatoes, yellow and orange fruits
Retinal – liver of polar bear, seal, eggs and fatty fish
18. VITAMINS D - CALCIFEROL
• maintain normal blood levels of Ca and P by promoting their
absorption from food in the intestines and reabsorption of Ca in the
kidneys, enabling normal mineralization of bones
2 major forms:
D2 – derived from precursor ergosterol present in plants
D3 – derived from precursor 7-dehydrocholesterol present in skin
Structure of provitamins of vitamin D - similar to steroid hormones
- derived from cholesterol
19. UV
7-dehydrocholesterol (skin) cholecalciferol
(provitamin) (D3, calciol)
UV
Ergosterol (plants) ergocalciferol (D2, ercalciol)
(provitamin)
Adequate amounts of vitamin D3 can be made in the skin after only
10 -15 minutes of sun exposure at least 2x per week to the face,
arms, hands, or back without a sunscreen
23. DEFICIENCY
◼ Results from a number of factors:
◼ inadequate intake coupled with inadequate sunlight
exposure
◼ liver or kidney disorders (impair conversion of
vitamin D into active metabolites)
24. DEFICIENCY
Leads to impaired bone mineralization, and to bone softening
diseases including:
• RICKETS - a childhood disease - impeded growth, and
deformity of the long bones
• OSTEOPOROSIS - reduced bone mineral density and
increased bone fragility
25. Odd curve to spine or
back
Wide joints at
elbow and
wrist
Odd-shaped
legs
26.
27. Vitamin D malnutrition may also be linked to an
increased susceptibility to several chronic diseases:
◼ high blood pressure
◼ cancer
◼ periodontal disease
◼ multiple sclerosis
◼ memory loss
◼ autoimmune diseases including type 1 diabetes
28. Overdose of vitamin D:
◼ Ca release from bones and its deposition in soft tissues
(kidneys, lungs gall bladder, endocrine glands) causing
their calcification
29. Sources of vitamin D
◼ Fish liver oils
◼ Fatty fish species
◼ A whole egg
◼ Beef liver, cooked
◼ mushrooms (Vitamin D2)
30. •
Benefits
• Protects lipids (cell membranes), DNA, proteins from
oxidation – ANTIOXIDANT
Protects food fats from going rancid
• Helps to form red blood cells
• Aids in the absorption of vitamin K
Vitamin E – Tocopherols
antisterile vitamin
31. Free radical
Cell
Mitochondria
Vitamin E protects cell membrane lipids from oxidation by reacting
with lipid radicals produced in the lipid peroxidation chain reaction
32. O
CH3
CH3 CH3 CH3
R3
R2
HO
R1
O
HO
CH3
CH3
CH3 CH3 CH3
R1 R2 R3
Tocol -CH3 -CH3 -CH3
-CH3 -H -CH3
-H -CH3 -CH3
-H -H -CH3
tocotrienol
STRUCTURE: tocol, forms 8 basic derivatives
α-tocopherol is the most effective form
Chromanol ring
HO- group - reduction of free radicals
Saturated side chain – penetration in membranes
R1
R2
R3
34. Vitamin K1 (phylloquinone) - from plant sources
Vitamin K2 (menaquinone) - made by intestinal bacteria
(production can be disturbed by antibiotics, Crohn disease)
Vitamin K3 (menadione, menadiol) - synthetic form
German „koagulation“ vitamin K
VITAMIN K - QUINONES
36. • Promotes normal blood clotting (coagulation)
• Bone metabolism
• Vascular health
Biochemistry
coenzyme of an enzyme carboxylase –
carboxylation of glutamic acid gamma-
carboxyglutamic acid (Gla) – involved in binding Ca2+
FUNCTIONS
39. Rare in healthy adults: 1) vitamin K widespread in foods
2) vitamin K cycle conserves vitamin K
3) large intestine bacteria synthesize vit. K
Deficiency
Adults at risk:
• those taking vitamin K antagonist - anticoagulant drugs
• adults with significant liver damage
• newborn babies – exclusively breast-fed:
1) vitamin K is not easily transported across the placental
barrier
2) the newborn's intestines are not yet colonized with bacteria
that synthesize menaquinones
3) the vitamin K cycle may not be fully functional in newborns
42. VITAMIN B1 – THIAMINE, ANEURINE
(antineuritic factor, antiberiberi factor)
PYRIMIDINE and THIAZOL rings linked through the
methylene bridge
Antagonists – Sulfites (food preservatives) – attack at the methylene
bridge
43. - cofactor for several enzymes (pyruvate dehydrogenase,
alpha-ketoglutarate dehydrogenase)
Thiamine diphosphate
COENZYME = thiamine diphosphate
- in the catabolism of saccharides and aminoacids
44. Deficiency
▪ severely reduced capacity of cells to generate energy
▪ BERI-BERI - neurological symptoms, cardiovascular
abnormalities, and edema with fatal outcome
It affects the nerves to the limbs, producing pain,
paralysis, and swelling
Natural Sources
Meat, potatoes, bananas, lentils, beans, yeast
Overdose
Hypersensitive reactions resembling anaphylactic shock
Interactions
Antibiotics - decrease thiamine level
49. Deficiency
Fatigue, red, swollen, cracked mouth and tongue, mouth
ulcers, cracks at the corners of the mouth
Riboflavin deficiency is often seen in chronic
alcoholics due to their poor dietetic habits
Overdose
Itching, numbness, a burning sensation
Storage
Riboflavin decomposes when exposed to visible light
This characteristic can lead to riboflavin deficiencies in
newborns treated for hyperbilirubinemia by phototherapy
50. Vitamin B3, Niacin, vitamin PP
Nicotinamide
Nicotinic Acid
Niacin is not a true vitamin in the strictest definition since it
can be derived from tryptophan.
nicotinic acid + vitamin
!
51. Nicotinamide adenine dinucleotide (NAD+) and Nicotinamide
adenine dinucleotide phosphate (NADP+) - cofactors for numerous
dehydrogenases (lactate, malate dehydrogenases) - acceptor of
during alcohol oxidation
NICOTINAMIDE ADENINE DINUCLEOTIDE (NAD+)
H-
NADH
-OH phosphorylated in NADPate
!
53. Function
• Niacin is a precursor to NADH, NAD+ - coenzymes of
oxido-reductases – transfer of hydrogen anion
• Nicotinic acid (but not nicotinamide) - lowers plasma
cholesterol levels (and TAG, LDL, VLDL) and has been
shown to be a useful therapeutic for hypercholesterolemia
• Elevates blood glucose and uric acid production (not
recommended for diabetics or gout)
54. Deficiency
Dermatitis on the hands and face, weakness
The severe symptoms, depression, dermatitis and
diarrhea - PELLAGRA (3D disease)
Natural Sources
Beef liver, brewer’s yeast, meat, eggs, grains and milk
57. Overview
• Pantothenate is required for synthesis of coenzyme A –
metabolism of saccharides, proteins, lipids.
• Growth factor for MO
• „Anti-stress vitamin“
Vitamin B5 – Pantothenic Acid
61. FUNCTIONS
➢ Affects the body’s use of proteins, saccharides
• a coenzyme in all transamination reactions, in some
decarboxylation and
deamination of amino acids
➢ PDP aids in the synthesis of heme
➢ Helps in absorption of vitamin B12 and formation of
erythrocytes
➢ Role in the conversion of tryptophan to serotonin – helps against
mental depression
62. ➢ Vitamin B6-magnesium - help attention deficit disorder -
improvements in hyperactivity, and improved school
attention
➢ Vitamin B6 - cure for premenstrual syndrome (PMS)
Deficiency
• Anemia
• Nerve damage (mental confusion, irritability, nervousness)
• Skin problems
• Sores in the mouth
Deficiencies of vitamin B6 are rare
64. FUNCTION
• Cofactor of enzymes that are involved in CARBOXYLATION
reactions (e.g. acetylCoA carboxylase, pyruvate carboxylase)
helps to transfer CO2
• Key role in the metabolism of lipids, proteins and saccharides
• It activates protein/amino acid metabolism in the hair roots and
fingernail cells - the “beauty vitamin” - often recommended for
strengthening hair and nails.
• Role in DNA replication and transcription
VITAMIN H - BIOTIN
66. DEFICIENCY
• hair loss, hair thinning
• brittle fingernails
• depression, halucination,
• muscle pain,
• dermatitis (skin rash, typically on the face)
Synthetized by intestinal bacteria - deficiencies rare
67. Deficiency occurs in:
• Alcoholics
• People with inflammatory bowel disease
• Someone who eats large quantities of raw egg whites
• Long-term antibiotic use
Raw eggs -
preventing absorption of biotin
vit. H deficiency
avidin from egg whites + biotin = complex
SOURCES
gut flora, liver, egg yolk, nuts, seeds, soya
68. :
Functions
• Nucleotide biosynthesis
• DNA and RNA synthesis and repair
• Important during periods of rapid cell division and growth
• Production of red blood cells, prevention of anemia.
• Antioxidant
Vitamin B9 - Folic Acid
Folacin
Benefits
• To carry and transfer various forms of one carbon units
(methyl, methylene, methenyl, formyl or formimino groups)
during biosynthetic reactions (purine nucleotides, dTMP)
• Promotes a healthy pregnancy
69. Folic Acid
positions 7 & 8 carry hydrogens in dihydrofolate (DHF)
positions 5-8 carry hydrogens in tetrahydrofolate (THF)
• Active form of folic acid - tetrahydrofolate (THF) – coenzyme F –
formylating coenzyme – transfer of 1-carbon moeities
pterin PABA Glutamic acid
• Folic acid is itself not biologically active, but derivative
tetrahydrofolate and other derivatives after folic acid conversion to
dihydrofolic acid in the liver
71. Spina bifida
• Malformation of the spine
• Lost ability to control bladder - urination,
• Impaired function of legs
72. Function
• Synthesis of DNA and erythrocytes
• Coenzyme during conversion of methylmalonyl CoA to succinyl
CoA
• Functioning of brain and nervous system
• Antioxidant
• B12 is used to regenerate folate in the body
VITAMIN B12 - Cobalamin
Natural Sources
Animal liver and kidneys, sardines, beef, tuna, salmon, dairy
products, eggs
74. B12 - protein
B12
protein
Intrinsic faktor (IF)
(stomach)
B12-IF
Absorption (small intestine)
B12-transcobalamine II
(circulation)
Transcobalamine II
B12 Synthesis
(MO) Hydrolysis (stomach)
75. Binding of B12-transcobalamin II to the cell
receptors
Endocytosis of the complex into cells
Degradation of the complex in lysosomes and liberation
of B12
Coenzyme of enzymes in the cell cytoplasm
76. Mouth
Salivary glands produce R-protein
Stomach
a. HCl and pepsin release vitamin B-12 bound
to protein in food
b. Free vitamin B-12 binds with R-protein
c. Parietal cells secrete IF (intrinsic factor)
Small intestine
a. Trypsin from pancreas releases R-protein
from vitamin B-12
b. Vitamin B-12 links with IF intrinsic factor
Ileum
Vitamin B-12/ Intrinsic factor complex is
absorbed into blood and binds to transport protein
transcobalamin II
Liver
Vitamin B-12 stored in liver
VITAMIN B-12 absorption
Small
intestine
Ileum
Stomach
Liver
Salivary
gland
77. Deficiency – develops if the body does not produce enough intrinsic
factor, or if you don’t eat enough vitamin-B12-rich foods
Pernicious anaemia
Nausea, loss of appetite, sore mouth
Deficiencies - rare
The liver can store up to six years worth of vitamin B12
Interactions
Tobacco/Alcohol - Reduces the absorption of vitamin B12
78. Blood cells of
pernicious anemia
The cells are larger than
normal and irregular in
shape
Normal blood cells
The size, shape and color
of these red blood cells
show that they are normal.
81. ✓ Antioxidant (prooxidant)
✓ Cofactor of enzymes used in the synthesis of collagen
✓Tyrosine degradation
✓ Adrenalin synthesis
✓ Carnitin synthesis
✓ Bile acids production
✓ Steroidogenesis
✓ Iron absorption
✓ Metabolism of bone minerals
FUNCTION
84. • Pigments for flower coloration producing yellow or red/blue
pigmentation
• They also protect plants from attacks by microbes and insects
VITAMIN P – BIOFLAVONOIDS
85. ❖ • Found in close association with vitamin C - vitamin C .
❖ • Bioflavonoids help maximize the benefits of vitamin C by
inhibiting its breakdown in the body
❖ • Antioxidants, antivirals, and anti-inflammatories
❖ • Protection against infections
❖ • Decrease the cholesterol level
Flavonoids
86. • Strengthening the walls of the blood vessels (rutin)
❖ • Preventing nosebleeds, miscarriages, postpartum bleeding,
and other types of hemorrhages
❖ • Protection against cancer and heart disease
❖ • Anticoagulant activity (preventing blood clotting)
❖ • Improvement of circulation
❖ • Improvement of liver function
❖ • Improvement of vision and eye diseases
Essencial compounds are rutin, hesperidin, quercetin.
87. Sources
Citrus fruits, grapes, black current, blackberries, blueberries,
cherries, apricots, cacao, tea
Absorption of the bioflavonoids can be slow, but small amounts
can be stored in the body
88. LIPOIC ACID
Coenzyme – aerobic decarboxylation and transacylation during
photosynthesis
Growth factor of several bacteria and protozoa
Antioxidant - acts in hydrophilic and lipophilic environment
- dihydrolipoic acid regenerates glutathione, vitamin
C and E
LIPOIC ACID
89.
90. Chelator
• Lipoic acid – chelates Cu2+, Zn2+ and Pb2+, but not Fe3+.
• Dihydrolipoic acid – chelates Cu2+, Zn2+ a Pb2+ and Fe3+.
- prooxidant – it can reduce Fe3+ to Fe 2+
• Lipoic acid intravenous administration - mushroom poisoning,
heavy metal intoxication
Sources - kidney, heart, liver, spinach, broccoli, peas, potatoes
Brewer´s yeasts
91. UBIQUINONE – COENZYME Q
• Present in the respiratory chain of mitochondria
• Transports electrones
• Important for energy production in cells
• Antioxidant
• It is not a vitamin - all animals, including humans, can synthesize
ubiquinones
• Fat soluble
97. Adenosine-5'-triphosphate (ATP)
• Transports chemical energy within cells for metabolism
• It is an energy source produced during photosynthesis and
cellular respiration
• It is consumed by many enzymes in biosynthetic reactions,
motility, and cell division.
98. • ATP - substrate in signal transduction pathways by
KINASES - phosphorylate proteins
ADENYLATE CYCLASE - uses ATP to produce the second
messenger cyclic AMP
• ATP is also incorporated into nucleic acids
• ATP has several negatively charged groups in neutral solution, it
can chelate metals with very high affinity
• Due to the strength of these interactions, ATP exists in the cell
mostly in a complex with Mg2+
cAMP
