Lecture Guide 10a Vitamins and Minerals I
Nutr 12
Material about vitamins and minerals can be found in Chapters 10 (Water-soluble vitamins), 11
(Fat-soluble vitamins), 12 (Major minerals), and 13 (Trace minerals)
Vitamins vs. Minerals
 Vitamins:
 Minerals:
Vitamins and Minerals in the Diet I

Essential

Specific functions
Vitamins and Minerals in the Diet II

Is taking extra amounts of vitamins or minerals better for your health?

Identify the most likely scenario:
History of Vitamins

Early 1900s:

Animal studies: purified diets impaired growth

Additions to diets improved growth:

Added butterfat to diet:

Added grain extract to diet:
1941: Known Vitamins
What is a Vitamin?
1.
2.
3.
4.
Classic Vitamin Deficiency Diseases
Vitamin C: _______Thiamin:________ Niacin:________ Vitamin D:________
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Classification of Vitamins
Water-soluble vitamins
General Properties of Vitamins
Water-soluble vitamins
 Associate with body fluids;
excreted in urine
Fat-soluble vitamins
Fat-soluble vitamins
 Do not associate with body fluids
Instability of Vitamin Structures
Vitamins may be destroyed by food processing and preparation:
Interactions of Vitamins with Other Substances

Vitamin and minerals

Nutrient-drug interactions

Vitamin C and cigarette smoking

Alcohol and nutrient metabolism
What is a Mineral?





Stability of minerals: indestructible!
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Major Minerals vs. Trace Minerals (Figure 12-9, p. 378)
Most prevalent minerals?___________ and ____________
Properties of Minerals
Major Minerals
Trace Minerals
DRI: >100 mg/day
DRI: < 100 mg/day
Examples:
Examples:
Toxicity with excess intake:
Toxicity with excess intake:
Bioavailability: how well do you absorb minerals?

Influences on absorption:
1.
2.
3. Interactions with vitamins:
4. Interactions with other minerals
5. Food compounds
Food Components that Reduce Mineral Absorption

Phytates, Oxalates, Tannins
The Study of Micronutrients

What to study (if discussed):
 Nutrient functions
 Effects of deficiency and/or toxicity
 Food sources
 Factors affecting absorption, metabolism, storage, or excretion
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General Functions of Vitamins and Minerals I

Assist protein function

Coenzymes

Cofactors
How does a vitamin coenzyme work? Riboflavin (Figure 10-5)
General Functions of Vitamins and Minerals II

Antioxidant role: protection from oxidative damage

Nutrient antioxidants:
Oxidation/Reduction Reactions

Oxidation:

Reduction:
(What is a “free radical”? see discussion on pp. 360-361)
Sources of Oxidation
Antioxidant Function of Vitamin C (Figure 10-16)
Focus on Vitamin C
Roles in the body:
1. Antioxidant
2. Collagen synthesis
3. Iron absorption
4. Other
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Vitamin C Deficiency
o Scurvy
o Deficiency symptoms:
Vitamin C in Foods
o RDA:
o Smokers:
o Sources:
Vitamin C – most popular micronutrient supplement…. why???

Linus Pauling’s 1970 book

UL: 2000 mg

Problems with excessive intake:

What does your body due with extra vitamin C????
Vitamin E – the other vitamin antioxidant

Fat-soluble

“Alpha-tocopherol”

Antioxidant in____________

Sources of vitamin E:
Figure: Vitamin E in the Cell Membrane
Why do Individuals Use Vitamin E Supplements?
Micronutrients Work Together to Maintain the Body’s
Structures/Functions… (next topics)
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Nutrients in Bone Health (Ca, P, Vit D, F)
Bone Overview
Bone: a living tissue
1. Bone protein:_________________
2. Bone cells:_______________
3. Mineral:__________________
Types of Bone: Cortical Bone and Trabecular Bone
Normal Bone Turnover
 Bone demineralization (osteoclasts)
 Bone mineralization (osteoblasts)
During bone growth:
During bone loss:
Gain and Loss of Bone throughout Life (Figure)
Roles of Nutrients in Bone Health

Calcium, phosphorus
 Fluoride

Vitamin D – a hormone
Function:
Vitamin D & Calcium Homeostasis (Figure)
Maintaining Blood Calcium Levels

Hormones:
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 Vitamin D and parathyroid hormone (PTH): ___________________
 Calcitonin: ___________________

Overall effects on calcium:

Small intestine:

Kidneys:

Bone:
(High blood calcium/low blood calcium are medical emergencies)
Lack of Vitamin D  Low Blood Calcium and Inadequate Bone
Mineralization
Rickets:
Osteomalacia:
Calcium’s Various Roles in the Body
99% in bone and teeth
Other roles:
1.
2.
3.
Recommended Calcium Intake: Why are RDAs so High?

Calcium RDA:

19 to 50 yr:

> 50 yr:
Answer:
Figure: Higher bone density decreases fracture risk
Figure: Bone losses over time compared (Fig. H12-3, p. 398)
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Figure: Average Calcium Intake vs. DRI
Figure: Calcium Content in Selected Foods
Calcium in the Diet

Target RDA: 1000 mg

Sources:

Milk:________ Cheese:_________

Fish with bones

Tofu (made with Ca)

Green leafy vegetables

Beans
Calcium Bioavailability (Fig. 12-15)
Calcium Supplements?

Types of supplements
o Carbonate vs. citrate; natural sources

Absorption considerations

Do supplements help bone density?

Possible problems?
Osteoporosis – Progressive Loss in Bone Mass*
Effects of Osteoporosis
 Bone fractures:
 Compressed spine
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Osteoporosis Risk
Factors that ↑ risk:
Factors that ↓ risk:
Vitamin D Nutrition

Hormone function:

Conditionally essential:

Few food sources:
Dietary Sources of Vitamin D: Table
RDA: 15 g/day
Vitamin D Synthesis (Fig. 11-9, Fig. 11-11)
Requires:
 Sun exposure:
 Liver
 Kidney
Who’s at risk of Vitamin D deficiency?

Inadequate UV light:

Health/lifestyle:
Resurgence of Rickets!

Breastfed infants*** (need supplements)

Kept out of sunlight or living in northern latitude

Darker-skinned children
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Concept Check: Calcium Status and Blood Calcium Levels
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