The VitaminsThe Vitamins
Chapter 10 & 11Chapter 10 & 11
The Water-Soluble Vitamins:The Water-Soluble Vitamins:
B and CB and C
(there are 8 B Vitamins)(there are 8 B Vitamins)
The Fat-Soluble Vitamins:The Fat-Soluble Vitamins:
A, D, E, and KA, D, E, and K
What are Vitamins?What are Vitamins?
- small organic molecules- small organic molecules
- essential nutrients- essential nutrients
- required in very small quantities- required in very small quantities
e.g.e.g. 5 5 g / day of Vit Dg / day of Vit D
400 400 g / day of folateg / day of folate
14 14 g / day of bioting / day of biotin
Compare this to the energy nutrientsCompare this to the energy nutrients
Energy NutrientsEnergy Nutrients
Assume a 2000 kcal / day dietAssume a 2000 kcal / day diet
% Carbs:% Carbs: ??
% Lipids:% Lipids: ??
% Proteins: % Proteins: ??
Energy NutrientsEnergy Nutrients
Assume a 2000 kcal / day dietAssume a 2000 kcal / day diet
% Carbs:% Carbs: 55% x 2000 kcal = 1100 kcal 55% x 2000 kcal = 1100 kcal
% Lipids:% Lipids: 30% x 2000 kcal = 600 kcal 30% x 2000 kcal = 600 kcal
% Proteins: 15% x 2000 kcal = 300 kcal% Proteins: 15% x 2000 kcal = 300 kcal
275 g Carbs, 67 g Lipids, 75 g Protein275 g Carbs, 67 g Lipids, 75 g Protein
What do Vitamins look like?What do Vitamins look like?
What do Fat Soluble Vitamins look like?What do Fat Soluble Vitamins look like?
What do Vitamins actually do?What do Vitamins actually do?
- they are co-factors or co-enzymes- they are co-factors or co-enzymes
- they help proteins perform various - they help proteins perform various functions within the body.functions within the body.
e.g. - enzymes in energy metabolisme.g. - enzymes in energy metabolism
- vision (Vit. A)- vision (Vit. A)
Coenzyme Action
The Water-Soluble Vitamins:The Water-Soluble Vitamins:
B and CB and C
Metabolic pathways
involving B Vitamins
Getting Proper Levels of Vitamins
If the guidelines of diet-planning are followed, individuals in the developed world should not have a problem.
However, there are things to consider:
1) Bioavailability2) Stability3) Solubility4) Toxicity
Understanding Dose Levels vs Health Effects
The B VitaminsThe B Vitamins
- Thiamin- Thiamin - Riboflavin- Riboflavin
- Niacin- Niacin - Biotin- Biotin
- Pantothenic acid- Pantothenic acid
- Pyridoxine- Pyridoxine
- Folate- Folate
- Cyanocobalamin- Cyanocobalamin
Lets look at 2……
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.
Thiamin
Pork is the richest source of thiamin, but
enriched or whole-grain
products typically make
the greatest contribution to a day’s intake because of the
quantities eaten.
Thiamin (TPP) - Vit BThiamin (TPP) - Vit B11
- involved in the- involved in theconversion of pyruvateconversion of pyruvateto acetyl-CoAto acetyl-CoA
- deficiency results- deficiency results
in a condition knownin a condition known
as beriberias beriberi
- damage to nervous- damage to nervous
system, brain function,system, brain function,
heart and muscles.heart and muscles.
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.
Folate(Folic Acid)
Leafy green vegetables,
legumes, liver, and
some fruits are
naturally rich in folate.
Folate (Folic acid)Folate (Folic acid)
- involved in the synthesis of DNA, - involved in the synthesis of DNA, especially in newly formed cellsespecially in newly formed cells
- deficiency results in anemia and GI - deficiency results in anemia and GI tract deteriorationtract deterioration
- in the developing fetus, neural - in the developing fetus, neural tube defects have been linked to low tube defects have been linked to low folate levelsfolate levels
When dietitians say “vitamin C,” people think “oranges,” but these foods also are rich in vitamin
C.
Vitamin C (Ascorbic Acid)Vitamin C (Ascorbic Acid)
Vitamin C (Ascorbic Acid)Vitamin C (Ascorbic Acid)
- deficiency results in scurvy- deficiency results in scurvy
- involved in the synthesis of - involved in the synthesis of collagencollagen
NH2
+
O
ONH2
+
O
O
OH
Ascorbic Acid(Vit. C)
Vitamin C
RDA(75 - 100 mg/day)
Linus Pauling
Common coldAnd
Heart Disease75
90
2000
The Fat-Soluble Vitamins:The Fat-Soluble Vitamins:
A, D, E and KA, D, E and K
Forms of Vitamin A
Vitamin A Deficiency
- 100 million children worldwide suffer from some form of Vit A deficiency
- Infectious Disease - Measles kills 2 million children each year
- Night Blindness and Xerophthalmia
- Keratinization
(RDA = 700 - 900 g / day)
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.
The carotenoids in
foods bring colors to
meals
….. the retinoids in
our eyes allow us to see them.
Retinol’s Role in Vision
Vitamin D Deficiency
- rickets in children
- osteomalacia in adults leading to osteoporosis
(AI = 5 g / day)
Vitamin D synthesis
and activation
Part from diet
Part from biosynthesis
Vitamin D synthesis and Latitude
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.
Vitamin D can be synthesized in the body with the help of sunlight or obtained from foods derived from animals. A deficiency causes rickets in childhood. Fortified Milk is an important food source.
Vitamin E Deficiency: -tocopherol
- Primary deficiency is very rare
- Secondary deficiency:(usually associated with a lack of fat absorption)
- Erythrocyte hemolysis
- Neuromuscular dysfunction
(RDA = 15 mg / day)
Free Radical Formation
O2 O2 H2O2 OH + H2O
e- 2 H+e- H+e-
.- .
protein
or
lipids(PUFA)
.OH+
protein
or
lipids(PUFA)
.
.
Anti-oxidant Protection AgainstFree Radicals
protein
or
lipids(PUFA)
.+ Vit. E
protein
or
lipids(PUFA)
.+ Vit. E
(active) (inactive)
.
Vit. E
(inactive)
+ Vit. C Vit. E
(active)
+ Vit. C.
Vitamin E Supplements
Vitamin E has 3 stereogenic centres
Therefore, when made synthetically:
2 x 2 x 2 = 8 different forms
ONLY 1 is the NATURAL & ACTIVE form
1 / 8th
Vitamin K Deficiency
- Primary deficiency is rare because it is produced from bacteria in the GI.
- Secondary deficiency: 1) altered fat absorption2) drugs such as antibiotics kill or
disrupt bacterial production of Vit. K
(AI = 90 - 120 g / day)
Vitamin K Deficiency
- Hemorrhagic disease
(uncontrolled bleeding)
- Bone Health - i.e. osteoporosis(involved in the activation of 3 bone
health related proteins)
- Calcification of Arterial Plaques(increased risks of heart disease
and arterial sclerosis)
©2001 Brooks/Cole, a division of Thomson Learning, Inc. Thomson Learning™ is a trademark used herein under license.
Notable food sources of vitamin K include:
milk, eggs, brussels sprouts,
collards, liver, cabbage,
spinach, and broccoli.
Phytochemicals in Disease Prevention
Phytochemicals -
metabolites produced by plants
e.g.
1) Antioxidant activity2) Phytosterols
Anti-oxidant Protection AgainstFree Radicals
protein
or
lipids(PUFA)
.+ Phyto chemical
protein
or
lipids(PUFA)
.
(active) (inactive)
.
+ Phyto chemical
Phytochemicals in Disease Prevention
Broccoli SproutsApples: Flavonoids
Garlic & Onions: Allicin (S)
Tomatoes: Lycopene
Flax: Lignan
Red Wine: Resveratrol