The document provides an extensive overview of fats, lipids, and vitamins, including their definitions, structures, classifications, sources, and functions in human health. Fats and lipids serve as essential energy sources and play critical roles in cellular structure, digestion, and nutrient absorption. Vitamins are also detailed, categorized into fat-soluble and water-soluble, highlighting their necessity for various physiological processes and specific food sources.

1. FATS/LIPIDS
VITAMINS

2. OUTLINE
• Definition of fats/lipids
• Structure of fats/lipids
• Classification of fats
• Sources of fats
• Digestion, absorption and metabolism of fats

3. FATS/LIPIDS
Substances that are generally insoluble in water but soluble
in organic solvents such as ether, acetone and chloroform.
Are essential part of the body accounting for a sixth of the
body weight.
Cells and tissues of the body have fat as an integral
component.
The vital organs are protected by a sheath of fat and water
which holds them in place to prevent injury

4. STRUCTURES OF FATS/LIPIDS
• Lipids are most often triglycerides which are made up of 3
fatty acids and glycerol.
• Triglycerides are generated by a condensation reaction and
the bond between fatty acid and glycerol is called an ester
bond.
• Fatty acids can be saturated (single bonds between all
carbons) or unsaturated (at least one double bond between
carbons). This determines whether the compound is a fat or
an oil.

5. STRUCTURE OF LIPIDS
• Composed of elements of carbon, hydrogen and oxygen-similar to
carbohydrates but less water.
• Triglycerides-The most common type of lipids made up of 3 fatty acid
chains attached to a glycerol backbone. Fatty acids are chains of
carbon atoms(14 and 22) with the end carbon containing a carboxyl
group(COOH). The fatty acids in the triglyceride could be the same or
have different structures.
• Glycerol has 3 carbons, with 3 OH molecules attached. The glycerol
backbone becomes attached to the 3 fatty acids through
condensation reaction because 3 molecules of water are formed

6. STRUCTURE OF LIPIDS

7. STRUCTURE OF LIPIDS
• The structure of fatty acids influences the structure of the lipid. In the
fatty acid chains, the carbon atoms could have a single bond between
them making the lipid saturated. This generates fat that are solid at
room temperature.
• If one or more of the bonds between the carbon atoms are double
bonds, the lipid is said to be unsaturated. If there is one double bond
the triglyceride is said to be monounsaturated. If it has multiple
double bonds it is polyunsaturated. Unsaturated fatty acids are
usually liquid at room temperature and are called oils.

8. STRUCTURE OF LIPIDS
• The bond that forms between the fatty acid chain and the glycerol is
called an ester bond.

9. CLASSIFICATION OF LIPIDS
• Lipids can be classified into 3 based on their chemical structure
1) Simple lipids-fats and oils
2) Compound lipids-phospholipids and lipoproteins
3) Derived lipids-fatty acids and sterols

10. SIMPLE LIPIDS
• Includes fats and oils
• Every fat molecule has a glycerol at its core and 3 fatty acids attached.
• Nature-depends on type of fatty acid linked to the glycerol.
• Saturated fatty acids are solid fats while oils contain unsaturated fatty
acids.
• Edible oils include- soya beans, sunflower, maize, cottonseed, sesame,
groundnuts, mustard, olive, coconut, Ghee.
• Sources of fats-visible fats including oil, vegetable, ghee and butter
• Invisible fat-oil seed and nut, mutton, eggs, liver and milk

11. COMPOUND LIPIDS
• Characterized by presence of a non-fat product(other than fatty acid
and alcohol) in the molecule according to the nature of that fat.
• They include the following subtypes
1) Phospholipids
2) Glycolipids
3) Lipoproteins
4) Sulfolipids and amino lipids

12. COMPOUND LIPIDS
PHOSPHOLIPIDS
 Contain phosphorus in the form of phosphoric acid groups which
contain substituted fats, composed of glycerol, fatty acids and
phosphoric acid bound in ester linked to a nitrogenous base.
 Lecithin is an important component of all membranes
 Shingomylins and cerebrosides are found in brain
 Are important components of active tissues(brain, nervous tissue and
the liver)
 Are emulsifying agents necessary for digestion and absorption of fats

13. COMPOUND LIPIDS
PHOSPHOLIPIDS
 Helps carry lipid particles across the cell membranes in the blood
stream.
 The body makes phospholipids on its own-no need for dietary
provision.

14. COMPOUND LIPIDS
FUNCTIONS OF PHOSPHOLIPIDS
 Present in large amounts in the liver, brain and blood.
 The membrane bounding cells and subcellular organelles are
composed of phospholipids
 Are important components of the lipoprotein coat essential for
secretion and transport of plasma proteins.
 Myelin sheath of nerves is rich with phospholipids.
 Important in digestion and absorption of neutral lipids.
 Cholesterol in bile

15. COMPOUND LIPIDS
FUNCTIONS OF PHOSPHOLIPIDS CONT.
 Important in blood clotting and platelet aggregation
 Provide lung alveoli with surfactant that prevents lung collapse.
 Important in signal transduction across the cell membrane.
 Source of polyunsaturated fatty acids
SOURCES OF PHOSPHOLIPIDS
Found in cells, milk and egg-yolk in the form of lecithin

16. COMPOUND LIPIDS
LIPOPROTEINS
 Lipids combined with proteins in tissues.
 The protein part of lipoprotein is called apolipoprotein
 The lipid component of lipoproteins are mostly triglycerides, free and
esterified cholesterol and phospholipids.
 Lipoprotein structure consist of non-polar lipid core surrounded by
apoproteins and more polar lipids

17. COMPOUND LIPOPROTEINS
CLASSES OF LIPOPROTEINS
1) Chylomicrons-Transport of lipids to adipose tissue for storage and to
muscles or heart for energy needs
2) Very low density lipoproteins(VLDL)-Transport of TG synthesised in
the liver as VLDL to the peripheral tissues
3) Low density lipoproteins(LDL)-Transport of cholesterol from liver to
peripheral tissues
4) High density lipoproteins(HDL)-Protective particles. Transport
cholesterol from tissues to the liver for synthesis of bile and steroid
hormones. HDLs play a key role in protecting against heart disease.

18. DERIVED LIPIDS
• Are the hydrolysis products of simple and compound lipids and/or
their derivatives that still possess the general characteristics of lipids.
• They include fatty acids, glycerol, steroids, bile acids and substances
associated with lipids in nature such as carotenes, vitamins A,D,K
and E.

19. FUNCTIONS OF LIPIDS
• Source of energy, each gram of fat supplies upto 10 calories.
• Source of essential fatty acids and fat soluble vitamins(A, D, K and E)
• Fats are used to synthesis phospholipids found in most cells.
• Fat stored as adipose tissue act as a cushion for vital organs. Also
protects nerve fibers.
• Helps conserve body heat and regulate body temperature. This is
because it is a poor conductor of heat.
• Increases the feeling satisfaction because of slow digestion.
• Forms an important component of cell walls.

20. DIGESTION, ABSORPTION AND METABOLISM
OF FAT
• Majority of ingested fats are triglycerols (TGAs)
• Mouth-enzymes are aqueous and have little effect on lipids
• In the stomach, fats are churned into droplets called chime.
• Gastric lipase begins digestion of fats, 10% of TAGs are hydrolyzed in
the stomach.
• Chyme stimulates cholecystokinin to release bile from the gall
bladder.
• Bile is an emulsifier for lipids

21. DIGESTION OF FATS CONT
Pancreatic lipase hydrolyzes insoluble triglyceride by binding to bile-salt
micelles.
TAGs are partially hydrolyzed, 2 of the 3 F.As have ester linkages
hydrolyzed and released.
A monoacyglyceral remains-glycerol + 1 fatty acid
Oil droplets form a spherical micelle shape aided by bile salts during
which clumping of fatty acids and monocylglycerols take place

22. DIGESTION OF FATS CONT
• Fatty acid micelle-hydrophobic fatty acids and monocylglycerols are in
the anterior and bile salts in the posterior.
• Micelles are small enough to penetrate the membrane of intestinal
cells.
• Free fatty acids and monoacylglycerols are reformed into
triacyglycerols.
• TAGs are combined with membrane and water soluble proteins to form
chylomicron a lipoprotein.
• Chylomicrons carry TAGs from the intestinal cell into the blood stream
via the lymphatic system

23. DIGESTION OF FATS CONT
• Triacylglycearols reach the bloodstream and are hydrolyzed down to
glycerol and fatty acids.
• These are absorbed by cells and processed further for energy by
forming acetyl CoA.

24. RDA FOR FATS
• Based on 2 factors-need to meet energy needs and essential fatty acid
needs.
• 12g of fat is needed daily by the body.
• A higher level of 20g/day may be needed to provide energy density
for normal adults.
• Maximum intake-20g/day for adults and 25g/day for children

25. VITAMINS

26. VITAMINS
• Organic substances which occur in small amounts in the body and are
essential for life and growth.
• Substance classified as vitamins satisfy the criteria below
Must be vital and only needed in very small amounts to perform
specific functions
Cannot be synthesized in the body and must be supplied in the diet

27. NATURE OF VITAMINS
 Occur in small amounts in the body.
 Are necessary for life and growth
 Chemical structure of each vitamin is specific
 Do not provide calories, but are essential for metabolic reactions
which release energy from carbohydrates, fats and proteins
 Are essential co-factors in many metabolic reactions
 Each vitamin has a specific function, one cannot substitute for
another

28. CLASSIFICATION OF VITAMINS
 Classified based on solubility
 Fat Soluble vitamins
Include A,D,E and K
 Water soluble
B group and vitamin C

29. FAT SOLUBLE VITAMINS
• Can only be absorbed in the presence of fat-presence of some fat in
the diet is essential for absorption.
• Can be stored in the body, high intake is protective during periods of
low intake.
• Requirements are met by intake of the vitamin or by intake of a
precursor.
• Not lost during cooking

30. VITAMIN A
• Occurs as retinoids (retinal, retinal, retinoic acid) and carotenes(α,β
and ϒ)
• Chief source in humans is beta-carotene which the body converts to
vit A in the intestinal mucosa during absorption.
FUNCTONS OF VITAMIN A
Function in vision-occurs in the retina and required for dark adaptation.
Health of epithelial cells-Deficiency results in suppression of normal
secretions and produces keratinized epithelium.
Immune response-Functions in T-cell mediated response

31. VITAMIN A
FUNCTIONS
Haemopoesis-Deficiency associated with iron deficiency anemia
Growth-Retonic acid controls growth and development of tissues in the
musculoskeletal system
Energy balance
CNS development
Gap junction development

32. VITAMIN A
SOURCES
Present in animal foods only-Liver, butter, ghee, milk, curds and egg
yolk
Leafy vegetables-spinach, amaranth, coriander and drumstick leaves .
Ripe fruits such as mango, papaya and pumpkins are sources of beta-
carotene.
RDA
Adult-600 mcg of retinal or 2400 mcg of beta-carotene
Infants 350 mcg of retinal

33. VITAMIN A EFFEECTS ACROSS THE LIFESPAN
Pregnancy
Morphological and functional development of the fetus
Lactation
Mammary gland metabolism
Regulates weaning process
Infancy and childhood
Maintains eye integrity
Boosters immune system

34. VITAMIN A EFFECTS ACROSS THE LIFESPAN
Adolescence
Xeropthalmia prevention
Dysplasia and anemia prevention
Early adulthood
Regulates immunity and vision
Obesity control
Middle age
Influences the risk of hip fractures
Beneficial in cases of open angle glaucoma

35. VITAMIN A EFFECTS ACROSS THE LIFESPAN
Elderly
Regulates fat mass
Affects bone mineral density

36. VITAMIN D
 Isolated in 1930 and named calceferol
 Called “sunshine vitamin”-the body is able to convert a precursor of
7-dehydrocholesterol to VIT D in the presence of sunlight
 Can be synthesized in the body by exposure to sunlight for five
minutes daily.
FUNCTIONS
Absorption of calcium and phosphorus
Bone mineralization

37. SOURCES OF VITAMIN D
 Found in small quantities in liver, egg yolk, milk and milk fat
 Fish liver oils,-halibut, cod, shark and sawfish taken as supplements
RDA
5 mcg or 200 IU is recommended for children
Recommendation for adults is not known

38. VITAMIN D EFFECTS ACROSS THE LIFESPAN
Pregnancy
Maintains maternal and fetal immune system
Improves bone health
Prevents pregnancy induced hypertension
Prevents pregnancy induced diabetes
Lactation
Prevents autism
Prevention of rickets

39. VITAMIN D EFFECTS ACROSS THE LIFESPAN
Infancy and Childhood
Improves immune function
Prevents childhood asthma
Participates in development of the nervous system
Adolescence
Bone development
Mental health maintenance
Boost the immune system

40. VITAMIN D EFFECTS ACROSS THE LIFESPAN
Early adulthood
Strengthens immune system
Lowers risk of multiple sclerosis
Lowers risk of type 2 diabetes mellitus
Middle age
Improves quality of life and physical performance
Lowers risk of sarcopenia
Elderly
Reduces risk of bone fractures and falls

41. VITAMIN E
 Also called alpha-tocopherol.
 No proof of vitamin E deficiency in adults has been established
 Main function – Fat soluble anti-oxidant
 Sources-Vegetable oils, cereals, leafy vegetables, milk, eggs, muscle
meats and fish
 RDA-0.8mg/g of essential fatty acids

42. VITAMIN E EFFECTS ACROSS THE LIFESPAN
Pregnancy
Decreases the risk of asthma in the babies
Reduces the risk of low birth weight infant
Lactation
Regulates the developmental process
Infancy and childhood
Decreases the risk of asthma and ataxia

43. VITAMIN E EFFECTS ACROSS THE LIFESPAN
Adolescence
Enhances physical activity
Enhances academic performance
Improves outcomes for patients with non-alcoholic liver disease
Early adulthood
Improves endothelial cell function
Middle age
Has anti-aging effects
Decrease's the risk of stroke occurrence

44. VITAMIN E EFFECTS ACROSS THE LIFESPAN
Middle age Cont’
Decreases the risk of fractures
Elderly
Is an immune booster
Maintains hemostasis

45. VITAMIN K
 Phylloquinone is the major form of VIT K found in plants and in food.
 Function-Blood clotting, essential for formation of thrombin in the
liver.
 Sources-Green leafy vegetables

46. VITAMIN K EFFECTS ACROSS THE LIFESPAN
Pregnancy
Lowers the risk of coagulopathy
Inhibits intrahepatic cholestasis of pregnancy
Lactation
Aids in coagulation factor formation
Infancy and childhood
Preventive treatment of bleeding associated with Vitamin K
deficiency

47. VITAMIN K EFFECTS ACROSS THE LIFESPAN
Adolescence
Important in healthy bone development
Maintains hemostasis
Early Adulthood
Suppression diabetes mellitus progression
Management of type 2 diabetes mellitus
Middle age
Lowers risk of heart disease
Lowers risk of hip fractures

48. VITAMIN K EFFECTS ACROSS THE LIFESPAN
Elderly
Has anti-hemophilia effects
Protects against osteoporosis

49. WATER SOLUBLE VITAMINS
 Consist of a large number of substances including ascorbic acid and B-
complex vitamins
 Are absorbed quickly in the body and the excessive amounts not
utilized are excreted in the body.
 Some are partly lost during cooking

50. VITAMIN B-COMPLEX
 6 B vitamins have been identified and grouped together. Definite
requirements of these vitamins have been established.
 All are essential for human nutrition.
 The B vitamins include thiamine, riboflavin, niacin, pyridoxine, folic
acid and vitamin B 12

51. THIAMINE
 Also known as Vitamin B1
 FUNCTIONS
A co-enzyme for the release of heat from glucose and its storage as fat.
Needed to maintain the normal functions of the GI system, nervous
system and cardiovascular system through production of energy.
 Sources-Pulses, nuts, oilseeds and whole grain, rice and fresh peas, leafy
vegetables and animal products such as milk, eggs, fish and meat
 RDA-0.5 mg per 1000 calories for all age groups

52. RIBOFLAVIN-VITAMIN B2
 Second vitamin discovered after niacin
 Function-Co-enzyme in energy production and tissue protein building.
 Sources-Milk and milk products, liver and kidneys, pulses, green leafy
vegetables, eggs and meat.
 RDA- 0.60mg/100 kcal

53. NIACIN
• Includes both nicotinic and nicotinamide.
• The amide is soluble in water and both are heat stable
• Functions-Acts as an important component of 2 co-enzyme NAD and
NADP. This aides in breakdown of glucose to provide energy
• Sources-Groundnuts, liver, milk, eggs, fruits and vegetables

54. PYRODOXINE
• Three naturally occurring derivatives of pyridoxine are known as
vitamin B6
• Function-Co-factor for enzymes connected with metabolism of amino
acids. Has a role in formation of antibodies.
• Sources-Pulses, wheat, meat, vegetables and fruits
• RDA-0.4 mgs for infants to 2 mgs for adults, 2,5 mgs for lactating and
pregnant women
• Deficiency-Signs include peripheral neuritis, anemia, glossitis and
seborrhic dermatitis

55. FOLIC ACID
• Pteroyl-mono-glutamic acid, first isolated in 1941
• Functions-Synthesis of metabolites in the body, synthesis of nucleic
acid.
• Sources-Green leafy vegetables, liver, legumes. Upto 50% can be lost
during cooking hence the need for supplementation especially in
pregnancy.
• Body requirements- 100 mcg daily for adults and 25mcgs for infants

56. VITAMIN B12
• Also called cyanocobolamine
• Functions-Promotes normal growth and development, essential
component of several enzymes necessary for synthesis of nucleic acid,
essential for functioning of bone marrow cells, nervous system and GI
tract.
• Sources-Organ meats, milk, eggs, fish and muscle meat.

57. ASCOBIC ACID (VITAMIN C)
• Isolated in 1932
• Function-Building and maintainace of tissue especially connective
tissues, building of strong capillary walls, partner in protein synthesis,
building resistance to infection, aides in absorption of iron.
• Sources-Citrus fruits, leafy vegetables, amaranth, cabbage and
drumstick leaves

58. MINERALS

59. INTRODUCTION
• These are essential nutrients that represent about 5-6% of the body
weight.
• Classified into 2 depending on the percentage of body weight and the
amount required in the diet.
• Major/macrominerals are present in the body at levels greater than
0.01% and are required in amounts greater than 100 mg/day and
have structural and regulatory roles.
• Macrominerals include calcium, phosphorus, sodium, potassium,
magnesium and chloride.

60. INTRODUCTION
• Trace/micronutrients are present in the body in at levels less than
0.01% and are required in the body in amounts less than 50 mg/day.
• They are important regulation, metabolism and healthy immune
functions.
• Trace elements include iron, cobalt, chromium, copper, fluoride,
iodine, manganese, selenium, zinc and molybdenum

61. FUNCTIONS OF MICRONUTRIENTS
• Cofactors in metabolism-trace elements are involved in modulating
enzyme activity
• Coenzymes in metabolism-many vitamins or third metabolites are
required in complex biochemical reactions. This ensures utilization of
major nutrients to provide energy, proteins and nucleic acid
• Genetic control-zinc is involved in transcription that bind to DNA and
regulates transcription receptors for steroid hormones and other
factors
• Are antioxidants-Reduces oxidative stress