Trace Minerals
By Jennifer Turley and Joan Thompson
© 2016 Cengage
Presentation Overview
• Explore functions, deficiency, adequacy, toxicity, and
food sources of the trace minerals: Iron (Fe), Zinc
(Zn), Iodine (I), Selenium (Se), Chromium (Cr),
Molybdenum (Mo), Copper (Cu), Manganese (Mn),
Fluoride (F), Cobalt (Co).
Iron Functions
• Is a component of hemoglobin, the
protein that carries oxygen in the blood
and myoglobin, the protein that makes
oxygen available for the muscle.
• Is a part of many other proteins and
cytochrome enzymes (such as those
required for electron transport in ATP
production as well as in liver
detoxification), other enzymes enzymes
(flavoproteins), and iron storage
proteins (transferrin, lactoferrin, and
ferritin).
Iron (Fe) Deficiency & Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI) Approx. <5- DRI: 8-18 mg/day RDI: (>UL) >45 mg/day
12 mg/day
18mg
Microcytic hypochromic
anemia
Central Nervous System:
mental apathy, cold, dizzy,
irritable, headache NeuroMusccular: weakness and
fatigue Skin: pallor
(paleness)
Normal functioning of Unlikely from food. Most likely
hemoglobin,
from supplements and a genetic
myoglobin,
disorder Cardio-Vascular:
cytochromes, enzymes, damages the cardiovascular
and iron storage
system Central Nervous System:
proteins.
damages the central nervous
system Gl System: constipation,
nausea, vomiting, and diarrhea
Skin: bronze/gray skin color
Other: damages the renal system
and the liver
Vegetarians have 1.8 times higher DRI value.
Adult deficient, adequate, toxic values
Anemia
• Anemia can be caused by:
– Shortage or abnormality of Red Blood Cells
(RBC’s) compromising O2 delivery.
– Nutrient Deficiencies: Iron (Fe), vitamin E,
vitamin B12, folate & others.
• Inadequate intake
• Blood loss & Parasitic infection for Fe
• Signs & Symptoms of Anemia are:
• Muscular Weakness, Tiredness/fatigue
• Mental Apathy & Headache
• Paleness/Pallor
Iron: Food Sources
• Heme (10-20% absorbed): clams,
oysters, organ meats, and red muscle
meats
• Nonheme (2-5% absorbed): highly
fortified cereals, soybeans, white
beans, pumpkin seeds, black-strap
molasses, and spinach
Iron in Foods
Only supplement to treat and/or prevent Iron deficiency Anemia in susceptible
individuals (up to 60 mg) with a Medical Doctor’s recommendation.
Iodine Functions
• Essential component of the
thyroid hormones thyroxine (T4)
and triiodothyronine (T3).
• Regulates the metabolic rate and
influences the function of brain,
muscles, heart, the pituitary
gland, and kidneys.
Iodine (I) Deficiency & Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI) Approx.
<100 µg/day
Hypothyroidism Other:
Cretinism (growth and
developmental
abnormalities and mental
retardation in utero and in
children), goiter, reduced
metabolic rate
DRI: 150 µg/day RDI: (>µL) > 1,100 µg/day
1 5 0 µg
Normal thyroid, brain,
organ, and metabolic
Hypothyroidism acute toxicity:
Weak pulse and cardiac irritability,
coma, burning of the mouth, throat,
and stomach, abdominal pain,
fever, nausea, vomiting, and
diarrhea, and cyanosis chronic
toxicity Goiter, hypothyroidism,
thyroiditis, sensitivity reactions,
thyroid cancer
Adult deficient, adequate, toxic values
Iodine: Food Sources
• Seafood.
• Iodine is found in the soil where sea
water once covered the earth so plants
grown in this soil contain some iodine.
• In areas that do not have iodine in the
soil, the development of iodine
deficiency has been very common.
• Iodized salt.
• Processed foods containing iodized salt
provide iodine.
Iodine in Foods
Zinc Functions
• Catalytic, structural, and regulatory functions
to support growth, development, and the
function of over 100 enzymes.
• Required for insulin synthesis, storage, and
release.
• Zinc throat lozenges have been shown to
help with the common cold and do not pose
toxicity risks when used for the duration of
the cold.
Zinc (Zn) Deficiency & Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI) Approx. <5- DRI: 8-11 mg/day
7 mg/day
RDI: 15 mg
(>UL) >40 mg/day
Gl System: decreased
Normal catalytic,
taste acuity, impaired
structural, and
appetite, diarrhea Skin:
regulatory functions.
acrodermatitis
enteropathica, poor wound
healing, eye and skin
lesions Other: retarded
growth and delayed sexual
maturation, impotence,
hair loss
Cardio-Vascular: decreased
HDL cholesterol Central
Nervous System: headache
Gl System: loss of appetite,
upper gastrointestinal pain,
nausea, vomiting, diarrhea, and
abdominal cramps Immunity:
altered and suppressed
immunity Other: reduced
copper status
Vegetarians have 1.5 times higher
DRI value.
Adult deficient, adequate, toxic values
Zinc: Food Sources
• Shellfish (not all seafood)
• Meats (especially red meats) &
organ meats.
• Whole grains and some fortified
cereals, but it is not as bioavailable
for the body.
Zinc in Foods
Adult DRI:
8-11 mg/day
Fluoride Functions
Bone & tooth calcification
• Stimulates new bone formation
• Prevents dental caries (cavities).
– Replaces the hydroxy portion of
hydroxyapatite with more decayresistant fluorhydroxyapatite (hardens
tooth enamel and stabilizes bone
mineral structure).
Fluoride (F) Deficiency & Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
DRI: 3-4 mg/day
(>UL)
Approx. <2-2.6
mg/day
RDI: none
>10 mg/day
Normal bone and
tooth health.
Formation of
decay-resistant
fluorhydroxyapatite
Acute toxicity: cardiac
arrhythmias, seizures and
coma, nausea, vomiting,
diarrhea, abdominal pain, and
excessive salivation
Chronic Toxicity: Fluorosis
(tooth & skeletal), stiffness or
pain in the joints,
osteosclerosis,
hypercalcification, muscle
wasting, and neurological
defects
Tooth decay
Adult deficient, adequate, toxic values
Fluoride: Sources
• Fluoridated water
– 1 ppm → 1 mg/liter
• Some marine fish
–Sardines where the bones
are consumed
• Tea
Quantitative data unavailable for graphical
analysis.
Selenium Functions
• Selenoproteins including:
– Glutathione peroxidase (antioxidant)
– Thyroid hormone actions
• Reduction-oxidation (redox)
– Vitamin C
– Other molecules
Selenium (Se) Deficiency & Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
DRI: 55 µg/day
(>UL)
Approx. <36 µg/day
RDI: 70 µg
>400 µg/day
Keshan disease
Cardio-Vascular:
cardiomyopathy
Normal
selenoproteins,
antioxidant, vitamin
C redox functioning
Selenosis
Central Nervous System:
fatigue, irritability, and
nervous system
abnormalities
GI System: GI distress,
garlic breath odor
Skin: skin rash
Other: hair and nail
brittleness and loss
Adult deficient, adequate, toxic values
Selenium: Food Sources
• Most reliable sources:
Meat, seafood, dairy as
selenomethionine or
selenocysteine
• Plant foods (grains, fruits,
vegetables), depending on
soil selenium content.
Selenium in Foods
Adult DRI:
55 μg/day
Manganese Functions
• Bone formation
• Amino acid, cholesterol, and
carbohydrate metabolism.
• Required for and/or activates
several metalloenzymes.
Manganese (Mn) Deficiency &
Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
DRI: 1.8-2.3 mg/day
(>UL)
Approx. <1.2-1.5 mg/day
RDI: 2 mg
>11 mg/day
Cardio-Vascular: reduced
blood cholesterol levels
Central Nervous System:
altered mood and
increased pain (in
reproductively capable
women)
Skin: scaly red-dermatitis
Normal bone
formation and
amino acid,
cholesterol, and
carbohydrate
metabolism
Central Nervous
System: effects
similar to Parkinson’s
disease
Neuro-Muscular:
tremors, rigidity of
limbs and truck, slow
gait and lack of
coordination
Adult deficient, adequate, toxic values
Manganese:
Food Sources
• Grains and grain
products (37%)
• Tea (20%)
• Vegetables (18%)
Manganese in Foods
Adult DRI:
1.8-2.3 mg/day
Molybdenum Functions
• Cofactor for molybdoenzymes
needed for the catabolism of
sulfur containing amino acids
and some RNA compounds
Molybdenum (Mn) Deficiency &
Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
DRI: 45 µg/day
(>UL)
Approx. <30 µg/day
RDI: 75 µg
>2000 µg/day
Poorly documented in
humans
Symptoms
documented with
specific genetic defect
and Chron’s disease
Normal
catabolism of
sulfur containing
amino acids and
some RNA
compounds
Poorly documented in
humans
High intakes rapidly
excreted in the urine
Cu deficiency/dysfunction
may increase risk of Mn
toxicity
Adult deficient, adequate, toxic values
Molybdenum:
Food Sources
Levels depend on soil quality
• Legumes
• Grain products
• Nuts
Quantitative data unavailable for
graphical analysis
Chromium Functions
• Potentiates the action of insulin
• May improve glucose tolerance
Chromium (Cr) Deficiency &
Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
DRI: 25-35 µg/day
(UL is Not Established)
Approx. <17-23 mg/day
RDI: 120 µg
Poorly documented in
humans
Three patients lacking
chromium in their TPN
solution experienced
weight loss, peripheral
neuropathy, and
increased free fatty acid
oxidation
Normal insulin
activity
Poorly documented
in humans
Individuals with
kidney and liver
disease may be more
susceptible to
chromium toxicity
Adult deficient, adequate, toxic values
Chromium: Food Sources
• Whole grains especially
the bran component
Levels reduced by grain
processing & increased in
• Some beers
acidic foods that are
• French wines
processed in stainless
steel cookware.
Quantitative data
unavailable for graphical
analysis.
Copper Functions
• Cofactor for antioxidant enzymes and in
the electron transport chain.
• Important for biosynthesis of melanin (a
skin pigment), collagen and elastin
(connective tissue proteins)
• A component of the enzyme ceruloplasmin,
which is instrumental in iron oxidation and
binding to transferrin.
• Helps maintain neurochemical balance and
inactivates histamine release during
allergic reactions.
Copper (C) Deficiency & Toxicity
Deficiency
Adequacy
Toxicity
(<66% of DRI)
DRI: 900 µg/day
(>UL)
Approx. <600 µg/day
RDI: 2,000 µg (2 mg)
>10,000 µg/day
Is rare in adults, has occurred in
prematurely born infants
Normal antioxidant
enzymes, electron
Bone & tooth: osteoporosis in transport chain,
infants and children
connective tissue, iron
Cardio-Vascular: normocytic oxidation,
hypochromic anemia
neurochemical
Immunity: leukopenia and
balance, and histamine
neutropenia
inactivation function
Inherited syndrome called
Menkes’ disease
Is low but may occur from
supplements and some
beverages and drinking water
GI System: abdominal
pain, cramps, nausea,
diarrhea, and vomiting
Genetic, Wilson's disease,
inability to excrete copper
causes liver damage
Adult deficient, adequate, toxic values
Copper: Food Sources
•
•
•
•
•
•
Organ meats
Seafood
Nuts & seeds
Whole grains
Wheat bran
Cocoa products
Copper in Foods
Adult DRI:
900 μg/day
Cobalt
• Cobalt is the central component vitamin B12
(cobalamin).
• See vitamin B12 for functions, food sources,
deficiency, and toxicity information.
Some Summary Points
• The trace minerals essential in human
nutrition have specific functions.
• DRIs and food sources are established
for all essential trace elements.
• Deficiency and toxicity sign and
symptoms are characterized for most of
these nutrients.
References for this presentation are the same as those
for this topic found in module 5 of the textbook