The document discusses the roles, sources, and deficiencies of various vitamins, categorizing them into fat-soluble and water-soluble types. It explains the essential biochemical functions of vitamins, their metabolic activities, dietary sources, and potential deficiencies that can lead to specific diseases. Additionally, the document highlights the importance of vitamins and minerals in promoting health and preventing various conditions.

1. Vitamins

2. • To recognize vitamins by name
• To understand their distribution in various
food sources
• To understand the signs and symptoms of
diseases resulting from deficiencies
• To understand their role in metabolism
Objectives:

3. A group of organic nutrients required in small
quantities for a variety of biochemical
functions and which , generally , cannot be
synthesized by body and must therefore be
supplied in the diet.
Vitamins
Vitamins are essential for several
enzymatic functions in human metabolism

4. ? They are categorized on basis of their solubility
- Fat soluble (Vitamin A,D,E and K) are soluble in
fats, bile salts increases their absorption and
they are fairly resistant to heating
- water soluble( Vitamin B and C)
Vitamin B complex are essential for normal cell
metabolism
Easily destroyed by cooking or food processing.
Vitamins

5. Dietary vitamin deficiency may
be caused by
• Inadequate dietary intake
• Inadequate intestinal absorption
• Inadequate utilization
• Increased requirements of vitamins by
the body
• Drug induced deficiency

6. Fat soluble vitamins
Vitamin A- is present in the diet as retinol or as
β-carotene
• Found in fish, liver, eggs, butter, yellow & green
vegetables, fruits
• Needed for healthy skin, eyes, bones, teeth.
• Function: Vitamin A(retinol) is the precursor of retinel,
the light-sensitive group in rhodopsin and other visual
pigments.
• Deficiency causes night blindness, skin disorders,
kidney stones

7. Vitamin A structure

8. ? Found in liver, fish, eggs, milk,
sunlight
? Needed for growth,
metabolism of calcium &
phosphorus
? It promotes synthesis of
osteocalcin which is needed
for bone mineralization.
? Deficiency causes rickets,
poor teeth and bones.
Vitamin D
❑ Metabolic activity of Vitamin D

9. Vitamin D Structure

10. VITAMIN D
❑ Vitamin D comprises a group of sterols;
the most important of which are
cholecalciferol (vitamin D3) & ergosterol
(vitamin D2).
❑ Humans & animal utilize only vitamin D3
& they can produce it inside their bodies
from cholesterol.
❑ Cholesterol is converted to
7-dehydro-cholesterol (7DC), which is a
precursor of vitamin D3.

11. VITAMIN D
❑ Exposure to the ultraviolet rays in the
sunlight convert 7-dehydro-cholesterol
(7DC) to cholecalciferol.
❑ Vitamin D3 is metabolically inactive until it is
hydroxylated in the kidney & the liver to the
active form 1,25 Dihydroxycholecalciferol.

12. VITAMIN E
❑The term vitamin E describes a
family of 8 antioxidants,
4 tocopherols (α,β, γ, & δ) and
4 tocotrienols.
❑α-tocopherol is the active form of
vitamin E in the human body.

14. FUNCTIONS
• The main function of vitamin E is anti
oxidant. It intercepts free radicals &
prevents destruction of cell membrane.
• It protects the fat in LDL from oxidation.
• It inhibits platelets aggregation.
• It enhances vasodilatation.
• It inhibits the activity of protein kinase C.

15. Vitamin E Dietary
Sources
❑ Vegetable oils
❑ Almonds & peanuts
❑ Avocado
❑ Spinach
❑ Carrots (least)

16. Vitamin E deficiency
•Severe vitamin E deficiency
causes:
Neurological symptoms (impaired
coordination) & muscle weakness.
Increased risk of cardiovascular
diseases
Hemolytic anemia in children

17. THERAPEUTIC USES
❑ Prevention of cardiovascular diseases
❑ Diabetes Mellitus
❑ Cancer prevention
❑ Boost immunity
❑ Dementia

18. TOXICITY
Excess vitamin E may cause:
✔ Impaired blood clotting leading to
increased risk of bleeding in some
persons.
✔It is recommended that vitamin E
supplements to be stopped one month
before elective surgery.

19. ? Found in whole grains, leafy vegetables, milk,
butter, vegetable oils
? Needed for healthy cell membranes, red blood
cells
? Converts free radicals to inactive forms that are
excreted in bile thus prevent hemolysis of RBCs
? Deficiency causes red cell rupture, muscle
disorders
Vitamin E

20. VITAMIN K
• The K is derived from the German
word Koagulation.
• There are 2 naturally occurring forms
of vitamin K. Plants synthesize
phylloquinone (vitamin K1) & bacteria
synthesize menaquinone-3 (vit K2).
• Menaquinone-4 is produced in animals
from vit K1, but its function is yet to be
discovered.

22. FUNCTIONS
•Vitamin K is needed for production of
vitamin K-dependent coagulation factors in
the liver.
•Other functions include:
✔Assist in bone mineralization. The
mineral binding capacity of osteocalcin
requires vit K.
✔Gas6 is vit K-dependent protein
identified in 1993. It is important for
neuronal function.

23. SOURCES OF VITAMIN K
Bacteria in large intestine produce
vit K2 and supply 40-50% of human
requirement.
Vegetable oils
Almonds & peanuts
Avocado & Broccoli
Spinach, Lettuce, parsley (raw)

24. ? Found in leafy vegetables, soybeans, made by
intestinal bacteria
? Needed for normal blood clotting
? Deficiency causes slow clotting, hemorrhaging.
Vitamin K
❑ This vitamin is the only acting coenzyme
among fat soluble vitamins

25. Water soluble vitamins
– B1
(Thiamine)
– B2
(Riboflavin)
– B3
(Niacin)
– B5
(Pantothenic Acid)
– B6
(Pyridoxine)
– B7
(Biotin)
– B9
(Folic Acid)
– B12
(Cobalamin)
❑ C (Ascorbic acid)
❑ Vitamin B Complex

26. ? Found in organ meats, whole grains,
vegetables
? Needed for proper functioning of
heart, nervous system, digestion
? Deficiency causes beriberi,
cardiovascular disorders.
Vitamin B1
(Thiamine)

27. Most vitamins act as
coenzymes
Thiamin
e Pyrophosphate
(Pi) from ATP
Thiamine pyrophosphate
(TPP)
This TPP molecule is a
coenzyme for all
Decarboxylation of alpha
keto acids like pyruvate

28. ? Found in liver, poultry, milk, eggs,
cheese, fish, green vegetables, whole
grain
? Needed for metabolism of protein,
carbohydrates, and fats
? Used to make FAD for metabolism
? Deficiency causes dime vision,
premature aging, sore mouth
Vitamin B2
(Riboflavin)

29. ? Riboflavin is a component of the flavin
coenzymes such as the FAD and FMN.
? It is mainly used in the energy metabolism of
Sugars and Lipids. The activation of FMN and
FAD is an ATP-dependent.

30. ? Food sources and distribution:
Fish, meat, poultry, cereal, nuts,
? Signs and symptoms of deficiency
- Pellagra (pella agra: rough skin) characterized
by inflammation of mucous membranes
- dermatitis( red itchy skin), diarrhea, red swollen
tongue observed in chronic alcoholics
? Needed for metabolism, digestion, nerves, skin
B3
(Niacin)

31. ? Niacin when activated it forms NAD+ which
when phosphorylated forms NADP+ which are
used as cofactors for many dehydrogenases.
Niacin
molecule

32. ? Food sources and distribution:
Ubiquitous
Easily destroyed by heating
? Signs and symptoms of deficiency
Very rare
Neuromuscular degeneration
B5
(Pantothenic acid)

33. ? Found in meats, liver, whole grains,
vegetables
? Needed for sodium and phosphorus
balance
? Deficiency causes anemia, nausea,
loss of appetite, nervousness
Vitamin B6
(Pyridoxine)

34. Vitamin B6
exists in 3 forms and
their corresponding phosphates
Pyridoxal phosphate
(PLP) acts as a cofactor
by participating in
transamination and
decarboxylation
reactions

35. ? Food sources and distribution:
Can be synthesized by intestinal bacteria
Found in most foods
? Signs and symptoms of deficiency
Very rare, include dermatitis, muscle pain
B7
(Biotin)

36. • Biotin is a coenzyme commonly
associated with enzymes
performing carboxylation reactions
eg
BIOTIN
- Acetyl CoA carboxylase
Acetyl-CoA + ATP + HCO3- <=> Malonyl-CoA + ADP + Pi + H+
- Pyruvate carboxylase involved in
gluconeogenesis.
Pyruvate + HCO3- + ATP <=> Oxaloacetate + ADP + Pi + H+

37. ? Found in green vegetables, liver, whole grains,
legumes
? Needed for manufacture of proteins and red blood
cells, needed for cell division, helps prevent spina
bifida
? Deficiency causes inflamed tongue, diarrhea, B12
deficiency.
? Its active form is tetrahydropholate (THF)
B9
(Folic Acid)

38. FOLIC ACID
❑ Folic acid is obtained from yeasts and
leafy vegetables as well as animal liver.
Animals can’t synthesize folate, thus, it
must come from diet.
❑ Folate is needed for synthesis of nucleic
acids
❑ Deficiency causes megaloblastic anemia
& neural tube defects in utero.
❑ Used for treatment of chronic hemolytic
anemia.

39. B9
(Folic Acid) structure

40. COBALOMIN (VIT B12)
❑ B12 functions as a cofactor for
enzymes required for the catabolism of
fatty acids & the conversion of
homocysteine to methionine.
❑ B12 is not available in plant &
deficiency may occur in strict
vegetarians & in pts with GIT
problems & those on prolonged
antibiotic treatment.
❑ Deficiency causes megaloblastic
anemia, SACDC, & high homocysteine
in blood which is a risk of IHD &
stroke.

41. ? Found in Liver, meats, eggs, cheese, dairy
products
? Needed for red cell production, healthy nervous
system.
? Deficiency causes pernicious anemia.
Vitamin B12 (Cobalamin)

43. VITAMIN C
▪ Humans, unlike other mammals, are
unable to make ascorbic acid & they
get it from food.
▪ Rich dietary sources are citrus juices
(orange, grapefruit & lime),
strawberry, Guava, tomato, sweet red
pepper & broccoli.
▪ Recommended daily intake is
between 15-120 mg/day
depending on age. Smokers & lactating

44. FUNCTIONS
❑ Collagen synthesis
❑ Antioxidant
❑ Synthesize of noradrenaline
❑ Carnitine synthesize
❑ Metabolism of cholesterol to bile salts

45. Vitamin C deficiency
❑ Severe deficiency leads to Scurvy with
the following manifestations:
Bleeding & bruising easily
Hair & teeth loss
Joint pain & swelling
Fatigue & lack of concentration

46. THERAPEUTIC USES
• Cardiovascular diseases
• Cataracts
• Diabetes Mellitus
• Cancer prevention
• Common cold
• Lead toxicity

47. ? Found in citrus and other fruits, leafy
vegetables, tomatoes, potatoes
? Needed for healthy blood vessels,
resistance to infection, healing
? Deficiency causes scurvy, bleeding
gums
Vitamin C (Ascorbic acid)

49. ? Some vitamins have ability to remove free
radicals from the body and thus act as
antioxidants
? This activity protects the body from heart
disease, cancer, alzheimer’s disease
? These vitamins include; carotenoids (vit A),
vitamin C and vitamin E
Antioxidants

50. Differences between water
soluble and fat soluble
vitamins

51. Vitamin Rich Diet

52. ? Discuss the two classes of vitamins, their
sources and implication in disease
? What are the differences between fat soluble
and water soluble vitamins
? Describe one way that vitamins are used in
the metabolic process
Questions

53. Importance of vitamins in preventing
diseases

54. Importance of vitamins in preventing
diseases

57. ? Calcium and phosphorous- needed for the
dramatic increase in skeletal growth.
? Iron – for transporting oxygen in the blood
stream and preventing anemia
? Zinc- vital for protein formation and gene
expression
Minerals include:
Vitamins include:
Vitamin A,E,C
Folate
Others include: Fiber for normal bowel
function, Cholesterol and sodium.

58. Key Mineral and Vitamin
Needs
? Calcium
◦ Essential for fetal development of bones and teeth
◦ Supplements might be needed in cases of poor
maternal stores or pregnancies involving more than
one fetus
? Iron and iodine
◦ Iron essential for increased hemoglobin synthesis
as fetal development and growth requires sufficient
oxygen
◦ Iodine is essential for production of more thyroxine

59. ? Folate ( Vitamin B)
◦ Builds mature red blood cells during pregnancy
◦ Needed during early periconceptional period
◦ Recommend daily folate intake of 600 mcg during
pregnancy, 400 mcg per day for non-pregnant
women during childbearing years
◦ Some women may require folate supplements
Key Mineral and Vitamin
Needs

60. Key Mineral and Vitamin
Needs
? Vitamin D
◦ Is a fat soluble vitamin which ensures absorption
and utilization of calcium and phosphorus for fetal
bone growth
◦ Daily intake of three to four cups fortified milk
◦ Exposure to sunlight increases endogenous
synthesis of vitamin D