A brief class for undergraduates

1. Vitamins
DR HARSIMRAT SINGH WARAICH
M.D

2. What are vitamins
 Complex substances that regulate body
processes
 Coenzymes (partners) with enzymes in reactions
 No calories, thus no energy

3. Naming Vitamins
 Each new vitamin is temporarily named when
discovered
 The naming of vitamins follows the letters of the
alphabet, starting with A; up to the letter K
 A, B, C, D, E, and K
 B has many subscripts
 F, G, and H were dropped

4. Criteria for Vitamins
 Cannot be synthesized in ample amounts in the
body
 Chronic deficiency is likely to cause physical
symptoms
 Symptoms will disappear once the vitamin level in
the body is restored
 Deficiency can cause permanent damage

5. Categories
Fat-solubleFat-soluble
Dissolve in fatDissolve in fat
Can be storedCan be stored
Water-solubleWater-soluble
Dissolve in waterDissolve in water
Carried inCarried in
bloodstream, notbloodstream, not
storedstored
A, D, E, KA, D, E, K C and B-complexC and B-complex
vitaminsvitamins
A and D excess can beA and D excess can be
harmfulharmful
Excess amounts mayExcess amounts may
cause extra work oncause extra work on
kidneyskidneys

6. Classification of Vitamins
FAT SOLUBLE
A
D
E
K
 B1- Thiamine
 B2 - Riboflavin
 B3 – Niacin
 B5 – pantothenic acid
 B6 –Pyridoxine
 B8 – biotin
 B 9-Folic acid
 B12 -Cyanocobalamin
 Vitamin C (ascorbic
acid)
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WATER SOLUBLE

7. Vitamin Absorption and
Storage
 All absorption takes place in the small intestine
 Fat-soluble vitamins
 Are absorbed in the duodenum
 Storage
 Vitamin A is mainly stored in the liver
 Vitamins K and E are partially stored in the liver
 Vitamin D is mainly stored in the fat and muscle tissue

8. The Location of Vitamin
Absorption
Preferentially
absorbed in jejunum
Folate
(Jejunum only)
Vitamin
B12
(Ileum
Colon
Thiamin
Riboflavin
Niacin
Biotin

9. Vitamin A (and
carotenoids)  Functions:
 Normal vision
 Protects from
infections
 Regulates
immune system
 Antioxidant
(carotenoids)
 Food sources:Food sources:
 Liver
 Fish oil
 Eggs
 Fortified milk or
other foods
 Red, yellow,
orange, and dark
green veggies
(carotenoids)

10. Causes of Vitamin A Deficiency
 Inadequate intake (strict vegetarian diet)
 Fat malabsorption
 Crohn's ileitis
 Pancreatic insufficiency
 Cystic fibrosis
 Cholestatic liver disease
 Severely limited protein intake

11. Vitamin A Deficiency
Clinical Manifestations
1. Night blindness
2. Bitot's spots
- Abnormal squamous cell proliferation and
keratinization of the conjunctiva
- Xerophthalmia: abnormal dryness of the conjunctiva
and cornea of the eye
3. Irreversible eye conditions:
-Xerosis
-Corneal perforation
-Keratomalacia
-Punctate keratopathy

12. Vitamin D (the sunshine
vitamin)
 Functions:
 Promotes absorption of
calcium and phosphorus
 Helps deposit those in
bones/teeth
 Regulates cell growth
 Plays role in immunity
 Sources:
 Sunlight (10 – 15
mins 2x a week)
 Salmon with bones
 Milk
 Orange juice
(fortified)
 Fortified cereals

13. Findings in Vitamin D Deficiency
 ↓ intestinal absorption of calcium and phosphorus
 Hypocalcemia
 Hypophosphatemia
 Phosphaturia
 Secondary hyperparathyroidism (bone
 Demineralization of bones
 Osteoporosis/ostoemalacia in adults adults
 Rickets in children
 Muscle pain/weakness

14. Vitamin E
 Functions:
 Antioxidant,
may lower risk
for heart
disease and
stroke, some
types of
cancers
 Sources:
 Vegetable oils
 Foods made
from oil
 Nuts
 Seeds
 Wheat germ
 Green, leafy
vegetables

15. Vitamin E Deficiency
 Vitamin E deficiency is uncommon due
to the abundance of tocopherols in our
diet
 Divided to:
 Subclinical (low serum tocopherol
level)
 Clinical
Neuromuscular disorders
Hemolysis

16. Vitamin K
 Functions:
 Helps in
blood
clotting
 Helps body
make some
other
proteins
 Sources:
 Body can
produce on its
own (from
bacteria in
intestines)
 Green, leafy
veggies
 Some fruits,
other veggies,
and nuts

17. Water Soluble Vitamins
 B1, thiamine
 B2, riboflavin
 B6, pyridoxamine
 B12
 Biotin
 Panothenic acid
 Niacin
 Folic acid
 Vitamin C
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18. Thiamin (B1)
Functions:
 Helps produce
energy from
carbohydrates
Sources:
Whole-
grain and
enriched
grain
products
Pork
Liver

19. Individuals at Risk for
Thiamine Deficiency
 Alcoholics
 Calorie-protein poor diet
 Severe malnutrition
 Malabsorption
 Gastric bypass
 Chronic renal failure
 Prolonged febrile illness

20. Thiamine Deficiency
 Beriberi
 Wernicke-Korsakoff syndrome
 Leigh's syndrome

21. Riboflavin (B2)
 Functions:
 Involved in cellular
metabolism,
oxidation - reduction
reactions; electron
transporter
 Essential component
of coenzymes
 flavin
mononucleotide
(FMN)
 flavin-adenine
dinucleotide (FAD)
 Sources:
 Liver
 Yogurt and
milk
 Enriched
grains
 Eggs
 Green, leafy
veggies

22. Patients at Risk for Vit. B2 Deficiency
 Avoidance of dairy products
 lactose intolerance
 Anorexia nervosa
 Malabsorptive syndromes
 Celiac sprue
 Malignancies
 Short bowel syndrome
 Inborn errors of metabolism
 defect in riboflavin synthesis

23. NIACIN (Vitamin B3)
Forms
 Nicotinic acid
 Nicotinamide
Functions:
• Component of NAD/NADP - essential for redox
reactions and hydrogen transport, metabolism of
carbohydrates, fatty acids, and proteins
Dietary sources:
 Meats (liver), milk, fish, whole-grain, nuts

24. Niacin (B3) Deficiency
 Defective metabolism
 Disease – pellagra – The Four D’s
 Dermatitis
 Diarrhea
 Dementia
 Death
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25. Pyridoxine (B6)
 Functions:
 Transamination and
decarboxylation of AA
 Gluconeogenesis
 Formation of
niacin/serotonin from
tryptophan
 Steroid hormone
modulation
 Sources:
 Chicken
 Fish
 Pork
 Liver
 Whole grains
 Nuts
 Legumes

26. Vitamin B6 Deficiency
 Overt deficiencies are rare
 Manifestations
 Stomatitis, glossitis, cheilosis
 Seborrheic dermatitis
 Irritability, confusion, depression
 Sideroblastic anemia

27. Folate (Folic acid)
 Functions:
 Produces DNA and
RNA, making new
body cells
 May protect against
heart disease
 Lowers risk of neural
tube defects in fetus
 Controls plasma
homocysteine levels
(related to heart
disease)
 Sources:
 Fortified and
enriched
grains
 Legumes
 Green, leafy
veggies
 Peanuts

28. Causes of Folate
Deficiency
Nutritional deficiency
Poor dietary intake
Alcoholism
Elderly (10% in pts >75 years)
Malabsorption
Sprue
IBD
Gastric bypass

29. Vitamin B12 (cobalamin)
 Functions:
 Works with
folate to make
RBC’s
 Helps body
use fatty
acids/amino
acids
 Sources:
 Animal
products
 Meat
 Fish
 Poultry
 Eggs
 Milk, other
dairy

30. Biotin (Vit. B7)
 Functions:
 Produces
energy
 Helps body
use proteins,
carbs, and
fats from
foods
 Sources:
 Eggs
 Liver
 Wheat germ
 Peanuts
 Cottage cheese
 Whole grain
bread

31. Pantothenic Acid (Vit B5)
 Functions
 Helps produce
energy by
helping the
body use
proteins, fat,
and
carbohydrates
from food
 Sources:
 Found in almost
all foods
 Meat, poultry, fish
 Whole grain
cereals
 Legumes
 Milk
 Fruits, veggies

32. Vitamin C
 Functions:
 Helps produce
collagen
(connective tissue
in bones, muscles)
 Keeps capillary
walls, blood vessels
firm
 Helps body absorb
iron and folate
 Heals cuts and
wounds
 Protects from
infection, boosts
immunity
 Antioxidant
 Sources
 Citrus fruits
 Other fruits,
veggies

33. Symptoms of Vitamin C Deficiency
 Swollen and bleeding gums
 Loosened teeth
 Arthralgias and joint effusions
 Lower extremities weakness
 Petechial hemorrhage
 Ecchymosis
 Slow wound healing
 Anemia
 Death

34. Conclusions
Diagnosis of deficiency can be difficult
History is a key to diagnosis of vitamin
deficiency
Blood tests are important in diagnosis
The majority of patients with unclear
diagnosis should receive vitamin
supplementation

35. Thank You