The science of nutrition 4th edition thompson manore vaughan chapter 07a

Chapter 7A Lecture

Chapter 7A:
In Depth: Vitamins
and Minerals:
Micronutrients
with Macro
Powers

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What Are Micronutrients?
• Vitamins and minerals that are needed in much
smaller amounts
• Essential to our survival
• Assist body functions such as energy
metabolism and the formation and maintenance
of healthy cells and tissues

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Vitamins
• Vitamins are carbon-containing compounds that
regulate a wide range of body processes
• Fat-soluble vitamins: A, D, E, and K
• Readily stored in the body's adipose tissue
• Can be toxic when taken in excess
• Megadosing: >10 times the recommended
intake

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© 2017 Pearson Education, Inc.


Vitamins
• Water-soluble vitamins:
• Vitamin C (ascorbic acid) and B-vitamins
(thiamin, riboflavin, niacin, vitamin B6, vitamin
B12, folate, pantothenic acid, and biotin)
• Not stored in large amounts (except vitamin
B12): must be consumed on a daily or weekly
basis
• Toxicity is rare
• Deficiency symptoms, including diseases or
syndromes, can arise fairly quickly
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© 2017 Pearson Education, Inc.


Minerals
• Naturally occurring inorganic (non-carboncontaining) substances
• All minerals are elements:
• Already exist in the simplest chemical form
possible
• Are not digested or broken down prior to

absorption
• Categorized as major, trace, or ultra-trace

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Minerals
Major: require at
least 100 mg per
day
- Sodium
- Potassium
- Phosphorus
- Chloride
- Calcium
- Magnesium
- Sulfur

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Trace: require less
than 100 mg per
day
- Flouride
- Iron
- Manganese
- Zinc

Ultra-trace:
require less than 1

mg per day
- Chromium
- Copper
- Iodine
- Molybdenum
- Selenium


© 2017 Pearson Education, Inc.


© 2017 Pearson Education, Inc.


© 2017 Pearson Education, Inc.


Vitamins and Minerals—Absorption
• Depends on their chemical form
• Dietary iron: heme (only in meats, fish, and
poultry) and non-heme (in plant and animal
foods, iron-fortified foods, supplements)
• Binding factors within the same food
• Other foods within the meal
• High-fiber foods (whole grains) and oxalic
acid (tea, spinach) decrease zinc and iron
absorption

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Chemical Transformation
• Many vitamins are modified after they are eaten
and absorbed:
• B-vitamins combine with other substances
• Combinations activate the vitamin when the
compound is needed
• Minerals: basic natures do not change, but may
undergo minor adjustments in their atomic
structure

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Micronutrient Metabolism
• Toxic overload is generally more likely to
develop from taking supplements than from
consuming foods
• Some micronutrient supplements may be
harmful to the health of certain groups of people
• Most minerals are better absorbed from animal
sources than from supplements

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Micronutrient Metabolism (cont.)
• Enriching low-nutrient foods with
vitamins/minerals does not turn them into
healthful foods

• Eating a variety of healthful foods provides more
nutrients, phytochemicals, and other dietary
benefits than do supplements alone
• Foods can provide a balance of micronutrients
and other factors that work together to enhance
health

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Micronutrient Metabolism (cont.)
• A healthful diet built from a variety of foods offers
social, emotional, and other benefits absent from
supplements
• In certain populations—such as pregnant women
—micronutrient supplements can play an
important role in promoting health

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Micronutrients: Preventing or Treating
Disease
• Adequate intake of these nutrients has been
associated with lower risk for certain diseases:
• Vitamin D and colon cancer
• Vitamin E and diabetes complications
• Vitamin K and osteoporosis
• Calcium and pregnancy-induced hypertension
• Chromium and blood glucose control in those

with diabetes
• Magnesium and muscle wasting in older
adults
• Potassium and high blood pressure
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Other Essential Micronutrients
• Research into emerging micronutrients is ongoing
• Some vitamin-like factors and trace minerals may have
beneficial health effects, such as:
• Carnitine
• Boron
• Nickle
• Silicon
• Not yet classified as essential micronutrients; more study
is needed
• In the future, we may develop individual micronutrient
profiles based on age, gender, and DNA

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Nutri-Tools: Build-a-Salad

PLAY

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Build-A-Salad