Trace/Toxic Elements, Vitamins, and Nutrition Flashcards
if a deficiency impairs a biochemical or functional process and replacement of the element corrects this impairment - this this element is considered________________
An Essential Element
If trace elements are of medical interest primarily because many of them are toxic - then these elements are considered_______________
Non-Essential Elements
These elements are needed in mg/dL concentration
Trace Elements
These elements are needed in μg/dL concentration
Ultra-trace Elements
What to collect a trace element sample with
Royal Blue Top with or without EDTA
Quantification of an element by measuring the intensity of emitted radiation from an aerosolized sample
Atomic Emission Spectroscopy
Determination of element quantity through the absorption of optical radiation by free atoms in the gas phase
Atomic Absorption Spectroscopy
What is:
–Most abundant metal in earth’s crust
Absorption, Transport, and Excretion
–Ingestion, inhalation, and parenteral absorption
–Concentrates in bone (50%) and lung (25%)
–Transported bound to proteins (transferrin)
–Urine accounts for 95% of excretion; 2% in bile
Health Effects and Toxicity
–Interferes with enzyme activity
–Encephalopathy, anemia, bone disease, and progressive dementia
Aluminum
–Both metallic and non-metallic properties
–Found in pesticides, pigments, manufacturing processes
–Largest source of exposure is food
Health Effects and Toxicity
–Acute and chronic states and fatal at low doses
–GI, cardiovascular, hepatic, dermatologic, renal involvement
–One of the most common poisons in history
Absorption, Transport, and Excretion
–Ingestion and inhalation
–Hepatic metabolism
–Organic arsenic is cleared rapidly; inorganic and methylated are more toxic
Arsenic
–Soft, bluish-white metal—can cut with a knife
–Used in industry, soil contamination
Absorption, Transport, and Excretion
–Ingestion (5%) and inhalation (10-50%)
–Higher in females and smokers than males and nonsmokers
–Urine accounts for 95% of excretion; 2% in bile
Health Effects and Toxicity
–No role in human physiology
–Affects liver, bone, immune, blood, pulmonary, and nervous systems
Cadmium
Used in manufacturing stainless steel
Absorption, Transport, and Excretion
Ingestion, inhalation and dermal absorption
Cr6+ easier to absorb and more toxic than Cr3+
Transported bound to albumin and transferrin
Health Effects and Toxicity
Cr3+ is an essential element for insulin action, Cr6+ an oxidizing agent
Lung irritation and dermatitis are more common; liver, kidney, and immune system
Chromium
–Relatively soft yet tough metal
–Excellent electrical and heat conducting
–Important cofactor and critical for the reduction of iron in heme synthesis
–Hepatic copper (10% of total copper in the body)
–Found in cornea, spleen, intestine, and lungs
Absorption, Transport, and Excretion
–Ingestion, inhalation, and dermal
–Transported bound to proteins (albumin)
–Bile accounts for 98% of excretion; <3% in urine/sweat
Health Effects and Toxicity
–Important for many metalloenzymes
–Hepatic and renal damage; neurologic symptom; mucous membrane irritant
–Wilson’s disease—copper rings in the eyes
Copper
Absorption, Transport, and Excretion
–Ingestion (10% of ingested is absorbed); Fe3+ must be reduced for absorption
–Transported bound to proteins (ferritin)
–Iron is lost primarily by desquamation of epithelia, red cell loss to urine and feces, and menstruation.
Health Effects and Toxicity
–Important for hemoglobin, myoglobin, enzymes
–Deficiency and overload states possible
–Also stored as ferritin and hemosiderin in BM, spleen, and liver
–Iron deficiency in 15% worlds population
Iron
Laboratory Evaluation of Iron Status
–Hemoglobin and RBC indices, total Fe, TIBC, % saturation, transferrin, and ferritin
Serum iron
–Measurement of serum iron concentration refers specifically to the Fe3+ bound to transferrin and not to the iron circulating in plasma.
–Early morning sample collection preferred because of diurnal variation
–No visible hemolysis
Transferrin
–Primary plasma iron transport protein, which bind iron.
–Saturated with approx. 25-30% iron
–The additional amount of iron that can be bound is the unsaturated iron-binding capacity (UIBC)
Iron
Total Iron-Binding Capacity (TIBC)
–The theoretical amount of iron that could be bound if transferrin and other minor iron-binding proteins present in the serum/plasma were saturated
–Can be indirectly determined using the sum of the serum, iron and UIBC
TIBC=transferrin x 1.18
Percent Saturation
–Also called transferrin saturation—is the ratio of serum iron to TIBC
–% sat = 100 x serum iron/TIBC
Ferritin
–The major iron storage protein for the body.
–Concentration of ferritin is directly proportional to the total iron stores in the body.
–Ferritin is a more sensitive and reliable test for demonstration of iron deficiency
Iron
–Soft, bluish-white, highly malleable, and ductile
–Previously used in gasoline and paint
Absorption, Transport, and Excretion
–Primarily ingestion and inhalation
99% is absorbed by RBC; liver, kidney and brain with highest in bone (90%)
–Urine accounts for 76% of excretion; 16% in feces, remainder in hair, sweat, nails
Health Effects and Toxicity
–No physiologic role
–Higher absorption in children; leads to neurologic symptoms and low IQ, anemia
Lead
–Used in production of steel
Absorption, Transport, and Excretion
–Primarily ingestion; inhalation and dermal limited
–Found mostly in fat and bone
–Bile accounts for majority of excretion
Health Effects and Toxicity
–Important for many metalloenzymes and enzyme activation
–Deficient and toxic states have been observed
–Deficient: clotting issues, dermatitis, elevated serum Ca, Phos, ALP
Toxicity: nausea, vomiting, headache, disorientation, anxiety, compulsive laughing or crying (manganese madness)
Manganese
–“quicksilver”, heavy, silvery metal, liquid at room temperature
–3 naturally occurring oxidation states Hg⁰, Hg¹⁺, Hg²⁺
–Absorption, Transport, and Excretion
–Inhalation most common; ingestion, cutaneous, –injection, dental
–Kidney major storage organ, followed by liver, spleen, and brain
–Fecal and urinary excretion
–Health Effects and Toxicity
–No physiologic role
–CNS and PNS toxicity; can damage most organs/tissues before symptoms occur
Mercury
Absorption, Transport, and Excretion
–Up to 80% absorbed by ingestion
–Found mainly in liver, skeleton, and kidneys
–Bound to α2-macroglobulin and RBC membranes
–Mainly urinary excretion
Health Effects and Toxicity
–Important cofactor for several enzymes
–Deficiency and toxicity is rare
Molybdenum
