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Week 9 - Vitamin
Vitamin
Definition
Organic components in food that are needed in very small amounts for
growth & for maintaining good health
Fat-soluble vitamin
Vitamin A, E, D & K
Water-soluble vitamin
Vitamin C
Vitamin requirements
Vary according to:
Age & Gender
Use of tobacco, drugs, & alcohol
Stress
Health Status
Vitamin deficiencies
When adequate amounts of nutrients are not available to sustain
biochemical functions
Primary deficiency
A nutritional deficiency as a result of decreased intake
Secondary deficiency
A vitamin deficiency caused by inadequate resorption, utilization,
increased requirements, excretions, or destruction
Groups at risk for deficiencies
Periods of rapid growt
Week 9 - Vitamin 1
, Medically compromised patients
Patients with substance abuse ises (e.g. alcohol, tobacco,
methamphetamine)
Psychological & physical stress
Vegans
Characteristics of fat-soluble vitamins
Called fat-soluble because they dissolve in lipid & fat solvents rather
than water
Fairly stable to heat, as in cooking
Organic substances (contain carbon)
Absorbed in intestine along with fats & lipids in foods
Require bile for absorption
Transported via the lymphatic system
Stored in liver & adipose tissues
Characteristics of water-soluble vitamins
Include B-vitamins & vitamins C
Organic substances
B-vitamins contain nitrogen
Act as coenzymes
Readily absorbed in the jejunum
Body stored very small amounts
Daily intake is necessary
Vitamin A
Retinoids (preformed): in animal products
70 - 90% absorption
Carotenoids (precursors)
Fruits & vegetables
9 - 22% absorption
Week 9 - Vitamin 2
, Functions
Vision in dim light
Growth: cell differentiation DNA/RNA synthesis), bone, tooth
development
Integrity of skin, mucous membraes
Maintenance of immune function
Did you know?
Retinol is converted to retinal in the eye
Night blindness may be the result of inadequate vitamin A to permit
rhodopsin production
Vitamin A deficiency during pre-eruptive stages of tooth development
leads to enamel hypoplasia & defective dentin formation
Vitamin A is also involved with normal teeth spacing & promotes
osteoblast function of the alveolar
Additionally
Absorption is optimal when body stores are depleted & when adequate
amounts of other interrelated nutrients are present
The presence of vitamin E & the hormone thyroxine also enhances
vitamin A utilization
The liver stored ~ 90% of vitamin A
Adequate serum proteins are necessary to mobilize vitamin A from the
liver
Sources
Retinoids (preformed)
Found in animal products
Liver
Fortified dairy
Fish
Fortified foods
Week 9 - Vitamin 3
Week 9 - Vitamin
Vitamin
Definition
Organic components in food that are needed in very small amounts for
growth & for maintaining good health
Fat-soluble vitamin
Vitamin A, E, D & K
Water-soluble vitamin
Vitamin C
Vitamin requirements
Vary according to:
Age & Gender
Use of tobacco, drugs, & alcohol
Stress
Health Status
Vitamin deficiencies
When adequate amounts of nutrients are not available to sustain
biochemical functions
Primary deficiency
A nutritional deficiency as a result of decreased intake
Secondary deficiency
A vitamin deficiency caused by inadequate resorption, utilization,
increased requirements, excretions, or destruction
Groups at risk for deficiencies
Periods of rapid growt
Week 9 - Vitamin 1
, Medically compromised patients
Patients with substance abuse ises (e.g. alcohol, tobacco,
methamphetamine)
Psychological & physical stress
Vegans
Characteristics of fat-soluble vitamins
Called fat-soluble because they dissolve in lipid & fat solvents rather
than water
Fairly stable to heat, as in cooking
Organic substances (contain carbon)
Absorbed in intestine along with fats & lipids in foods
Require bile for absorption
Transported via the lymphatic system
Stored in liver & adipose tissues
Characteristics of water-soluble vitamins
Include B-vitamins & vitamins C
Organic substances
B-vitamins contain nitrogen
Act as coenzymes
Readily absorbed in the jejunum
Body stored very small amounts
Daily intake is necessary
Vitamin A
Retinoids (preformed): in animal products
70 - 90% absorption
Carotenoids (precursors)
Fruits & vegetables
9 - 22% absorption
Week 9 - Vitamin 2
, Functions
Vision in dim light
Growth: cell differentiation DNA/RNA synthesis), bone, tooth
development
Integrity of skin, mucous membraes
Maintenance of immune function
Did you know?
Retinol is converted to retinal in the eye
Night blindness may be the result of inadequate vitamin A to permit
rhodopsin production
Vitamin A deficiency during pre-eruptive stages of tooth development
leads to enamel hypoplasia & defective dentin formation
Vitamin A is also involved with normal teeth spacing & promotes
osteoblast function of the alveolar
Additionally
Absorption is optimal when body stores are depleted & when adequate
amounts of other interrelated nutrients are present
The presence of vitamin E & the hormone thyroxine also enhances
vitamin A utilization
The liver stored ~ 90% of vitamin A
Adequate serum proteins are necessary to mobilize vitamin A from the
liver
Sources
Retinoids (preformed)
Found in animal products
Liver
Fortified dairy
Fish
Fortified foods
Week 9 - Vitamin 3
