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……

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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