The Vitamins

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The Vitamins

• Chapter 10 11

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The Water-Soluble Vitamins B and C (there are 8
B Vitamins) The Fat-Soluble Vitamins A, D, E,
and K
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What are Vitamins?
- small organic molecules - essential
nutrients - required in very small
quantities e.g. 5 ?g / day of Vit D 400
?g / day of folate 14 ?g / day of
biotin Compare this to the energy nutrients
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Energy Nutrients
Assume a 2000 kcal / day diet
Carbs ? Lipids ? Proteins ?
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Energy Nutrients
Assume a 2000 kcal / day diet Carbs 55 x
2000 kcal 1100 kcal Lipids 30 x 2000 kcal
600 kcal Proteins 15 x 2000 kcal 300 kcal
275 g Carbs, 67 g Lipids, 75 g Protein
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What do Vitamins look like?
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What do Fat Soluble Vitamins look like?
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What do Vitamins actually do?
- they are co-factors or co-enzymes - they
help proteins perform various functions within
the body. e.g. - enzymes in energy
metabolism - vision (Vit. A)
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Coenzyme Action
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The Water-Soluble Vitamins B and C
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Metabolic pathways involving B Vitamins
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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) Bioavailability 2) Stability 3
) Solubility 4) Toxicity
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Understanding Dose Levels vs Health Effects
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The B Vitamins - Thiamin - Riboflavin -
Niacin - Biotin - Pantothenic acid -
Pyridoxine - Folate - 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 days intake
because of the quantities eaten.
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Thiamin (TPP) - Vit B1 - involved in
theconversion of pyruvateto acetyl-CoA -
deficiency results in a condition known as
beriberi - damage to nervous system, brain
function, heart and muscles.
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Folate (Folic Acid) Leafy green vegetables,
legumes, liver, and some fruits are naturally
rich in folate.
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Folate (Folic acid) - involved in the
synthesis of DNA, especially in newly formed
cells - deficiency results in anemia and GI
tract deterioration - in the developing fetus,
neural tube defects have been linked to low
folate levels
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Vitamin C (Ascorbic Acid)
When dietitians say vitamin C, people think
oranges, but these foods also are rich in
vitamin C.
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Vitamin C (Ascorbic Acid) - deficiency results
in scurvy - involved in the synthesis of
collagen
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2000
Vitamin C RDA (75 - 100 mg/day) Linus
Pauling Common cold And Heart Disease
90
75
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The Fat-Soluble Vitamins A, D, E and K
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Forms of Vitamin A
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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 mg / day)
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The carotenoids in foods bring colors to
meals .. the retinoids in our eyes allow us to
see them.
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Retinols Role in Vision
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Vitamin D Deficiency
- rickets in children - osteomalacia in
adults leading to osteoporosis (AI 5 mg / day)
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Vitamin D synthesis and activation
Part from diet Part from biosynthesis
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Vitamin D synthesis and Latitude
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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.
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Vitamin E Deficiency a-tocopherol
- Primary deficiency is very rare -
Secondary deficiency (usually associated with a
lack of fat absorption) - Erythrocyte
hemolysis - Neuromuscular dysfunction (RDA
15 mg / day)
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Free Radical Formation
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Anti-oxidant Protection Against Free Radicals
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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
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Vitamin K Deficiency
- Primary deficiency is rare because it is
produced from bacteria in the GI. - Secondary
deficiency 1) altered fat absorption 2)
drugs such as antibiotics kill or disrupt
bacterial production of Vit. K (AI 90 - 120 mg
/ day)
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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)
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Notable food sources of vitamin K include
milk, eggs, brussels sprouts, collards, liver,
cabbage, spinach, and broccoli.
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Phytochemicals in Disease Prevention
Phytochemicals - metabolites produced by
plants e.g. 1) Antioxidant activity 2)
Phytosterols
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Anti-oxidant Protection Against Free Radicals
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Phytochemicals in Disease Prevention
Broccoli Sprouts
Apples Flavonoids
Garlic Onions Allicin (S)
Red Wine Resveratrol
Flax Lignan
Tomatoes Lycopene