This document provides an overview of pharmacology of vitamins. It defines vitamins, classifies them as fat-soluble or water-soluble, discusses their history of discovery. It then covers the epidemiology of common vitamin deficiencies in India and describes various vitamins (A, D, E, K, B1, B2, B3, B5, B6, B12, and folic acid) in detail, including their sources, functions, deficiencies, uses, dosages and toxicity. The document aims to educate about the essential roles and clinical implications of vitamins.

1. PHARMACOLOGY OF
VITAMINS
- Dr. Amit D. Sharma
1st Year Resident, Department of
pharmacology

2. Contents
• DEFINITION
• CLASSIFICATION
• HISTORY
• EPIDEMIOLOGY
• VITAMINS IN SEGMENTS
• TAKE HOME MESSAGE

3. DEFINITION
• Vitamins are essential organic
compounds that are required in
very small amount and are involved
in fundamental functions in the
body, such as growth, maintenance
of health, and metabolism.
• The word "vitamin" comes from the
Latin word vita, means "life".

4. Classification
FAT SOLUBLE WATER SOLUBLE
A
D
E
K
B1- Thiamine
B2 - Riboflavin
B3 – Niacin
B5 – Pantothenic acid
B6 –Pyridoxine
B7 – Biotin
B9-Folic acid
B12 -CyanoCobalamine
C vitamin (ascorbic acid)

5. Vitamine to vitamin. The early years
of discovery
Clinical Chemistry 43, No. 4, 1997
In 1897 Christiaan Eijkman
-Professor of physiology
whose demonstration that
beriberi is caused by poor
diet led to the discovery of
vitamins

6. Vitamine to vitamin. The early years
of discovery
In 1911 Casimir Funk isolated a
pyrimidine - related concentrate
from rice polishing
His analysis indicated that the
concentrate contained nitrogen
in a basic form and was probably
an amine. Since it appeared to be
vital to life, Funk named it
“vitamine”

7. Vitamine to vitamin. The early years
of discovery
• In 1920, Jack Cecil
Drummond suggested
that, since there was no
evidence to support
Funk’s original idea that
these indispensable
dietary constituents were
amines, the final “e” be
dropped and to have a
name ending in “in”

8. Epidemiology of common vitamin
deficiencies in India
• Prevalence of vitamin A deficiency in India is among the
highest in the world
• It is the cause of blindness in 24% of children in blind schools
of India
• In case of vitamin D, it has been estimated that 1 billion
people worldwide have vitamin D deficiency or insufficiency
• There is widespread prevalence of varying degrees (50- 90%)
of vitamin D deficiency with low dietary calcium intake in
Indian population
Bhattacharjee.et.al .Indian Journal of Ophthalmology.2008; 56 (6)
Journal of the Associations of the Physicians in India november 2011 v oL . 59

9. Vitamin A
 Three forms :-
retinol, retinal and retinoic acid
 Sources :-
animal – retinol
vegetable – provitamins ( carotenes) which are
converted to vitamin A in liver
 Normal Laboratory value :adult – 20-100 mcg/dl
 Functions :-
• Control gene expression through two type of transcription receptors
– RAR (retinoic acid receptor) and RXR (retinoid X receptor)
• Control epithelial cell proliferation and differentiation(retinoic acid)
• Formation of rhodopsin for night vision(retinal)

10. Deficiency :-
Causes :
Inadequate dietary intake
Pregnancy
Lactation
Mal-absorption syndrome
Hepato-biliary disease

11. Deficiency :-
Manifestations:
• Xerophthalmia -involves xerosis (dryness)
of eye, ‘bitot’s spots’, keratomalacia (softening
of cornea), corneal opacities, night blindness
(nyctalopia) progressing to total blindness
• Dry and rough skin with papules, hyperkeratinization
• Keratinization of bronchopulmonary epithelium,
increased susceptibility to infection
• Diarrhea due to unhealthy gastrointestinal
mucosa
• Growth retardation

12. Uses :-
1. Tretinoin(all trans-retinoic acid) and adapalene, isotretinoin,
tazarotene (synthetic retinoid) -acne vulgaris
2. Alitretinoin -kaposi’s sarcoma
3. Beta-carotene –in skin photosensitivity in erythropoietic
protoporphyria
4. Retinoic acid – oral leucoplakia and tretinoin – promyelocytic
leukemia
5. Acitretin and tazarotene -psoriasis
-Isotretinoin and acitretin -teratogenic activity
6. Children with measles are given vitamin A
 Prophylaxis : 4000 IU/day, treatment : 50000-100000 IU/day
 Toxicity : 100000 IU/day for more than 3 weeks

13. Vitamin D
 Storage forms (Prohormones) :
vitamin D2(ergocalciferol)
vitamin D3(cholecalciferol)
 Active forms (Hormones) :
1,25(OH)2 ergocalciferol
calcitriol
 Sources :-
Fish liver oil, milk products
Laboratory value: adult -
Calcitriol : 15-75 pg/ml
Calcidiol : 30-100 ng/ml

14.  Functions :-
• Intestinal absorption of calcium and
phosphorus
• Mineralization of bones
• Renal retention of calcium and
phosphorus
•Maturation and differentiation of
mononuclear cells
•Influences cytokine production and
immune function

15.  Causes of impaired vitamin D action:
• Vitamin D deficiency
• Impaired cutaneous production
• Dietary absence
• Malabsorption
 Accelerated loss of
vitamin D
• Increased metabolism
(barbiturates, phenytoin,
rifampin)
• Impaired enterohepatic
circulation
• Nephrotic syndrome
• Impaired 25-
hydroxylation
• Liver disease, isoniazid
 Impaired 1 alpha-
hydroxylation
• Hypoparathyroidism
• Renal failure
• Ketoconazole
• 1 alpha-hydroxylase mutation
 Target organ resistance
• Vitamin D receptor mutation
• Phenytoin

16.  Deficiencies :-
In children, vitamin D
deficiency causes rickets
In adults, vitamin D
deficiency leads to
osteomalacia,
causing bone pain and
muscle weakness
 Dose : 200-400 IU/day
 Toxicity: >50000IU/day

17.  Uses :-
1. Rickets in children :
a)Vitamin D resistant rickets
(Vitamin D receptor mutation),
b)Vitamin D dependent rickets
(Renal 1alpha-hydroxylase mutation),
c)Renal rickets
2. Osteomalacia in adult
3. Hypoparathyroidism
4. Calcipotriol-in plaque type psoriasis

18. Vitamin E
 Chemistry
Alpha tocopherol - most abundant and potent
 Source :-
Cottonseed oil, corn oil, sunflower oil, wheat germ oil – richest source
 Normal Laboratory value :adult - 5-18 mcg/ml
 Function:
Vitamin E protects red blood cells as an antioxidant and helps
utilization of vitamin A
 Manifestations of deficiency :-
 Muscular dystrophy
 Hemolytic anemia
 Hepatic necrosis

19. :Uses -
1.Vitamin E deficiency
2.G-6-PD deficiency
3.Acanthocytosis
4.Retrolental fibroplasia in premature infants
5.Hypervitaminosis A
6.Intermittent claudication
7.Nocturnal muscle cramps
 Adult : 400 mg/day, children : 200 mg/day

20. Vitamin K
 Types with sources:-
1. Vitamin K1( phytonadione) : green leafy vegetables
2. Vitamin K2( farnoquinone) : product of metabolism of
bacteria
3. Vitamin K3( menadione) : synthetic analogue, three
times more potent
 Normal Laboratory value: adult – 0.13-1.19 ng/ml
 Function
 Helps in Blood Clot Formation
 Vitamin K2 plays an important role in
bone formation
 Vitamin K Prevents Cardiovascular
Disease

21. Vitamin K Cycle and connection to
clotting pathways
Valchev et al. 2008, Furie et al. 1999

22. Vitamin K is a cofactor for the formation of gamma-carboxyglutamic
acid residues on coagulation proteins just like prothrombin, factor VII,
IX and X
 Vitamin K antagonist :-
Warfarin, dicumarol and acenocoumarol ( oral anticoagulants)
 Contraindicated in pregnancy – fetal warfarin syndrome
In maintenance therapy of acute DVT or pulmonary embolism
following an initial course of heparin
Preventing venous thromboembolism in patients undergoing
orthopedic or gynecological surgery, recurrent coronary ischemia in
patients with acute myocardial infarction
Vitamin K and The Clotting Cascade

23.  Deficiency :-
Liver disease
Obstructive jaundice
Malabsorption syndrome
Prolonged broad spectrum
antimicrobial therapy
Prolonged use of sulpha drugs
 Uses :-
1. Deficiency state of vitamin K
2. Hemorrhagic disease of
newborn
3. Prolonged high dose salicylate
therapy
4. Overdose of oral
anticoagulants
 Dose : 50-100 mcg/day

24. Vitamin B1(Thiamine)
 Sources :-
-whole grains, pulses, nuts, green vegetables, yeasts,
eggs and meat
-tea, coffee, raw fish and shellfish contain thiaminase
that destroys thiamine
 Normal Laboratory value: adult – 0-2 mcg/dl
 Functions :-
• Thiamine phosphate, active form of thiamine, serves as a
cofactor for several enzymes involved in carbohydrate
catabolism
• It also helps in the hexose monophosphate shunt that
generates nicotinamide adenine dinucleotide phosphate
(NADP) and pentose for nucleic acid synthesis
• Synthesis of acetylcholine and gamma-aminobutyric acid
(GABA)

25.  Deficiency :-
Causes :
 Poor dietary intake
 Alcoholism
 Advanced gastric cancer
 Prolonged hyper emesis gravidarum
 Prolonged anorexia
 Bariatric bypass surgery for morbid obesity
 Chronic diuretic therapy
 Polished rice based diets

26. Manifestations :
• Early stage – anorexia, irritability,
decrease in short term memory
• Prolonged deficiency – beriberi
• dry (neuritic) type and wet
(cardiac) type
• Alcoholics – wernicke’s
encephalopathy
• TRMA(thiamine responsive
megaloblastic anemia)

27. Uses
1. Treatment and prevention of thiamine
deficiency, including a specific disorder
called Wernicke-Korsakoff syndrome
(WKS) that is related to low levels of
thiamine (thiamine deficiency) and is
often see in alcoholics
2. Correcting problems in people with
certain types of genetic diseases
including Leigh's disease, maple syrup
urine disease, and others

28. Vitamin B2(Riboflavin)
 Sources :-
dairy products, cereals, breads, fish, eggs, legumes
riboflavin is extremely sensitive to light
 Normal Laboratory value: adult – 4-24 mcg/dl
 FAD(flavin adenine dinucleotide) and FMN(flavin
mononucleotide) – cofactor in oxidation-reduction reactions,
important for metabolism of carbohydrate, protein and fat
 Deficiency :-
Early – cheilosis, seborrhoea, magenta tongue, angular
stomatitis
Late – corneal vascularization, anemia and personality
changes

29. Vitamin B3(Niacin)
 Sources :-
liver, meat, fish, cereal husk, nuts, pulses
 Nicotinic acid :-
 Hypolipidemic agent – lowers LDL-C and triglycerides, increases
HDL-C
 Profound adverse effects profile
 Contraindicated in pregnancy, peptic ulcer, diabetic and gout
patients
Functions:
Nicotinic acid and nicotinamide are biologically active
derivatives -- precursors of two coenzymes, nicotinamide
adenine dinucleotide (NAD) and NAD phosphate (NADP),
important in numerous oxidation-reduction reactions and
adenine diphosphate–ribose transfer reactions involved in DNA
repair and calcium metabolism

30.  Deficiency :-
Pellagra :
(pelle = skin, agra = rough)
Found in –population eating
high corn-based diet
-- Alcoholics
-- Hartnup disease
-- Carcinoid syndrome
Characterized by dermatitis,
diarrhea and dementia
Incidence more in women

31.  Uses:
Treatment of pellagra
Nicotinic acid – hypolipidaemic
- in peripheral vascular
disease

32. Vitamin B5(Pantothenic acid)
 Sources:
 liver, mutton, whole grains, egg yolk and vegetables
 Component of co-enzyme A;
- Involved in carbohydrate, fat, steroid and porphyrin
metabolism
- Heme synthesis
- Formation of ketone bodies
- Acetylcholine formation
- Citric acid formation, TCA cycle starter
 No clinical deficiency

33. Vitamin B6(Pyridoxine)
 Sources :
liver, meat, egg, soybean, vegetables and whole grain
 Normal Laboratory value: adult – 5-30 ng/ml
 Functions:
Pyridoxal phosphate acts as a coenzyme in –
 Synthesis of nonessential aminoacids
 Tryptophan and sulphur containing amino acid metabolism
 Formation of 5-HT, dopamine, histamine, GABA and amino-
levulinic acid

34.  Deficiency :-
Causes
 Isoniazid causes pyridoxine deficiency
 Hydralazine, cycloserine and penicillamine interfere
pyridoxine utilization
 Oral contraceptives
Manifestations :
Seborrheic dermatitis
Growth retardation
Mental confusion
Convulsion
Peripheral neuritis
Sideroblastic anemia
 High intake – sensory neuropathy and dependence
 Promote peripheral decarboxylation of levodopa

35. Vitamin B12
 Sources :-
 Just animal source – liver, kidney, sea fish, egg yolk, meat and
dairy products
 Laboratory value : adult –279-996 pg/ml
 Functions :-
 Conversion of homocysteine to methionine – protein
synthesis
 Formation of S – adenosyl methionine, needful for
phospholipid and myelin synthesis
 Cell growth and replication
 Intrinsic factor, secreted by parietal cells of gastric mucosa is
required for absorption

36.  Deficiency :-
Causes :
- Addisonian pernicious anemia
- Gastric mucosal damage
- Malabsorption
- Fish tapeworm infection of gastrointestinal tract
- Strict vegetarians
- Pregnancy due to increased demand
Manifestations :
- Megaloblastic anemia
- Glossitis, achlorhydria
- Subacute combined degeneration of and
spinal cord, mental changes
 Dose : cyanocobalamin 100-1000 mcg/day I.M. on alternate days for
2 weeks followed by once a month; methylcobalamin 1000-1500
mcg/day oral

37. Folic Acid
 Sources :-
liver, green leafy vegetables, egg, meat, milk
 Normal Laboratory value: adult –(RC) 150-450 ng/ml cells
--(S) 5.4-18 ng/ml
 Functions :-
FA(inactive)  DHFA  THFA(coenzyme) by folate reductase
and dihydrofolate reductase respectively  mediates number
of one carbon transfer reactions---
 Conversion of homocysteine to methionine
 Generation of thymidylate – constituent of DNA
 Conversion of serine to glycine
 Purine synthesis
 Histidine metabolism

39.  Deficiency :-
Causes :
- Inadequate dietary intake
- Malabsorption
- Chronic alcoholism
- Pregnancy and lactation
- Prolonged therapy of anticonvulsants and oral contraceptives
Manifestations :
- Megaloblastic anemia
- Epithelial damage
- Neural tube defects in offspring
- General debility, weight loss, sterility

40. Prophylactic folic acid
supplementation in 2nd and 3rd
trimester along with vitamin K in
the last month of pregnancy is
recommended, in women receiving
antiepileptic drugs to minimize
neural tube defects and bleeding
disorder respectively in the
neonate

42.  Pyrimethamine : used in combination with sulfonamide or
dapsone for treatment of falciparum malaria by inhibiting
plasmodial dihydrofolate reductase
 Methotraxate : used in choriocarcinoma, children with acute
leukemias, non-hodgkin lymphoma, breast,bladder,head and neck
cancers; rheumatoid arthritis, psoriasis and as an
immunosuppresant
 Cotrimoxazole – bacterial folate metabolism blocker; is utilized
for urinary tract infections, respiratory tract infections,
pneumocystis jiroveci, chancroid and bacterial diarrhea
 Dose : 1-5 mg/day

43. Biotin( Vitamin B7 )
 Sources :
- Liver, kidney, milk and milk products, egg yolk
- Vegetables, legumes and grains
 Coenzyme for carboxylases required for various CO2 transfer reactions
in fatty acid metabolism, aminoacid catabolism, gluconeogenesis
 Deficiency occurs in :( experimental)
- prolonged raw egg white intake
- biotin-free total parenteral nutrition
Symptomatology :
dermatitis of extremities, anemia, muscle pain, depression,
somnolence, anorexia
infants – hypotonia, lethargy, apathy, alopecia

44. VITAMIN C (ASCORBIC ACID)
 Sources :-
 Citrus fruits like amla, green leafy vegetables, potatoes,
tomatoes
 L- ascorbic acid is naturally occurring form
 Laboratory value for adult – 0.4-1 mg/dl
 Functions:-
 Cellular oxidation-reduction reactions
 Collagen synthesis
 Absorption of iron
 Formation of catecholamine,serotonin,
ferritin and tetrahydrofolate
 Role in stress

45.  Deficiency :-
Scurvy -- Only seen in malnourished infants, children,
elderly, alcoholics and drug addicts
Manifestations :
- Capillary fragility increased
- Delayed wound healing
- Swollen gums
- Poor dentine formation in children
- Poor mineralization of bone
- Anemia
 ‘Bachelor’ scurvy
 Dose :
prophylaxis 50-500 mg/day,
Scurvy 1-1.5 gm/day

46. Take home message
 Assess the adequacy of vitamin in
your diet
 If you are falling 75% below for
several vitamins, you may want to
supplement your diet with a
vitamin pill
 BUT THERE IS NO SUBSTITUTE FOR
A HEALTHY DIET
 The best way to get your vitamins
is through natural resources

47. Thank you