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(<66% of DRI) Approx. <5-12 mg/day

AdequacyDRI: 8-18 mg/day RDI: 18mg

Toxicity(>UL) >45 mg/day

Microcytic hypochromic anemiaCentral Nervous System: mental apathy, cold, dizzy, irritable, headache Neuro-Musccular: weakness and fatigue Skin: pallor (paleness)

Normal functioning of hemoglobin, myoglobin, cytochromes, enzymes, and iron storage proteins.

Unlikely from food. Most likely from supplements and a genetic disorder Cardio-Vascular: damages the cardiovascular system Central Nervous System: damages the central nervous system Gl System: constipation, nausea, vomiting, and diarrheaSkin: bronze/gray skin color Other: damages the renal system and the liver

Adult deficient, adequate, toxic valuesVegetarians have 1.8 times higher DRI value.

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

(<66% of DRI) Approx. <100 µg/day

Adequacy

DRI: 150 µg/day RDI: 1 5 0 µg

Toxicity

(>µL) > 1,100 µg/day

Hypothyroidism Other: Cretinism (growth and developmental abnormalities and mental retardation in utero and in children), goiter, reduced metabolic rate

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(<66% of DRI) Approx. <5-7 mg/day

AdequacyDRI: 8-11 mg/day RDI: 15 mg

Toxicity(>UL) >40 mg/day

Gl System: decreased taste acuity, impaired appetite, diarrhea Skin: acrodermatitis enteropathica, poor wound healing, eye and skin lesions Other: retarded growth and delayed sexual maturation, impotence, hair loss

Normal catalytic, structural, and regulatory functions.

Cardio-Vascular: decreased HDL cholesterol Central Nervous System: headacheGl 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 decay-resistant fluorhydroxyapatite (hardens tooth enamel and stabilizes bone mineral structure).

Fluoride (F) Deficiency & Toxicity

Deficiency(<66% of DRI)

Approx. <2-2.6 mg/day

Adequacy DRI: 3-4 mg/day

RDI: none

Toxicity (>UL)

>10 mg/day

Tooth decay Normal bone and tooth health. Formation of decay-resistant fluorhydroxy-apatite

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

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(<66% of DRI)

Approx. <36 µg/day

Adequacy DRI: 55 µg/day

RDI: 70 µg

Toxicity (>UL)

>400 µg/day

Keshan diseaseCardio-Vascular: cardiomyopathy

Normal selenoproteins, antioxidant, vitamin C redox functioning

SelenosisCentral Nervous System: fatigue, irritability, and nervous system abnormalitiesGI System: GI distress, garlic breath odorSkin: skin rashOther: 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(<66% of DRI)

Approx. <1.2-1.5 mg/day

Adequacy DRI: 1.8-2.3 mg/day

RDI: 2 mg

Toxicity (>UL)

>11 mg/day

Cardio-Vascular: reduced blood cholesterol levelsCentral 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(<66% of DRI)

Approx. <30 µg/day

Adequacy DRI: 45 µg/day

RDI: 75 µg

Toxicity (>UL)

>2000 µg/day

Poorly documented in humansSymptoms documented with specific genetic defect and Chron’s disease

Normal catabolism of sulfur containing amino acids and some RNA compounds

Poorly documented in humansHigh intakes rapidly excreted in the urineCu 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(<66% of DRI)

Approx. <17-23 mg/day

Adequacy DRI: 25-35 µg/day

RDI: 120 µg

Toxicity (UL is Not Established)

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

• Some beers • French wines

Levels reduced by grain processing & increased in acidic foods that are 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(<66% of DRI)

Approx. <600 µg/day

Adequacy DRI: 900 µg/day

RDI: 2,000 µg (2 mg)

Toxicity (>UL)

>10,000 µg/day

Is rare in adults, has occurred in prematurely born infants

Bone & tooth: osteoporosis in infants and childrenCardio-Vascular: normocytic hypochromic anemiaImmunity: leukopenia and neutropeniaInherited syndrome called Menkes’ disease

Normal antioxidant enzymes, electron transport chain, connective tissue, iron oxidation, neurochemical balance, and histamine inactivation function

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