Element Testing (Lab Dx)
ESSENTIAL TRACE MINERALS
--13 known essential to health: iron, copper, zinc, iodine, selenium, boron, cobalt, chromium, molybdenum, manganese, vanadium, silicon, nickel
--present in micrograms of mineral per gram of tissue
--iron, copper, molybdenum: redox rxns
---zinc: catalases, maintain carboxypeptidase structure
--selenium, iodin, silicon, boron: form covalent bonds with carbon and oxygen, in structural and enzyme prots
--hair testing only useful for a few of them
MACROMINERALS
--six macrominerals: calcium, magnesium, phosphorus, sodium, potassium, chloride
--in free ionic form Ca and Mg regulate enzyme activity
--electrolytes: Na, K, Cl
HEAVY METALS
--lead, cadmium, mercury, arsenic, aluminum, antimony, uranium, nickel
--??nickel is essential and heavy??
--harmful to physiology even in small amounts
--enzymes, nervous sys, kidneys, liver, heart, skin, etc
FUNCTIONAL RESPONSE TO MINERAL INTAKE
--deficient-->enzyme activity interference, structural prots disturbed
--high intake-->toxicity if more than can excrete
--optimal-->everything works, nothing toxic
ABSORPTION
--acid in stomach dissociates minerals from food
--pancreatic bicarb neurtalizes chyme-->
forms mineral complexes with organic acids and negatively charged aa's-->
increase absorption
ASSESSING MINERAL STATUS
--serum or plasma "popular" specimens but don't accurately reflect whole body status
--whole blood best for STAT determinations of Na and K
--also useful for acute toxic metal poisoning
--RBC's and WBC's: intracellular material BEST correlation with nutritional status
--URINE: only works if renal excretion is adequate and dietary consumption not variable
HAIR
--controversial, screening for heavy metals, easy to get sample, mb used for DOA
--poor standardization among labs, disagreement about sample prep, wide variation in "normals"
--hair easily contaminated, perception of legitimacy borderline, interpretation tricky
--overlap btw dz and normal, not enough studies
--hair: 80% prot, 15% water, .25-.95% mineral
--during anagen phase follicles produce hair at 1 cm/mo
--can't use hair that's been chemically treated
--no more tears shampoo for a 2 wks prior to remove contaminants in other shampoos
--element concentration relatively high (compared to blood & urine)
--elements last indefinitely in hair
**** ELEMENTS ****
ALUMINUM
--accumulate in bone and brain more than hair
--heavy: lead, cadmium, mercury, arsenic, aluminum, antimony, uranium, nickel
ANTIMONY
--in hair of industrial workers
--low body wt kids
ARSENIC
--infant levels correspond to intro of cereals into diet
--affinity for sulfhydryl groups and is rapidly cleared from blood (6-12 hrs)
--heavy: lead, cadmium, mercury, arsenic, aluminum, antimony, uranium, nickel
BORON
--hair reflects long term intake but sensitive to contamination
CADMIUM
--high in cigarette smokers
--leads to HTN
--heavy: lead, cadmium, mercury, arsenic, aluminum, antimony, uranium, nickel
CALCIUM
--hair: wide variation, depends on Ca++/PO4 ratio in diet
--hair: pts with high P:ca ratio show Ca up to 3x normal
--better test serum
--inverse relationship btw CV dz and Ca level
--decreased Ca correl w/ MI, osteoporosis
--urine: useful to monitor tx
--closely regulated by parathyroid
--ionized CA a better measure in serum
--six macrominerals: calcium, magnesium, phosphorus, sodium, potassium, chloride
CHROMIUM
--in hair 100x more concentrated than blood, mb useful indicator as is easier to measure
--incr in gestational DM, low in type I and II DM
--ultra-trace, difficult to measure
--80% excreted in urine, mb most valid indicator of status
--glucose intake increases plasma and urinary chromium
COBALT
--hair levels correlate with body stores, if low check MCV
COPPER
--serum is best indicator but don't decrease until stores are severely depleted
--95% of serum Cu is bound to ceruloplasmin, so test for ceruloplasmin
--principle excretion is biliary
--hair is reasonable indication of status but no correlation with Wilson's dz
--external contamination (copper algicides in swimmingpools) causes trouble with hair eval
LEAD
--correlates with reduced intelligence
--heavy: lead, cadmium, mercury, arsenic, aluminum, antimony, uranium, nickel
LITHIUM
--HAIR is a RELIABLE indicator OF NUTRIENT status, low in violent criminals
--low lith correl w/ cobalt, mb useful for B12 metab
--low lith assoc w/ B12, folate: depression, behavioral defects, learning disabilities
MAGNESIUM
--hair correl w/ diet and supp
--incr dt bone mobilization
--high levels in Prader-Willi syndrome (PWS), dyslexia too
--low in serum may indicate def
--highin serum correlate poorly with total body stores
--BEST index: intracellular content, WBC Mg content correl well with muscle cell content
--normal WBC content: .98-2.82micrograms/ml
--muscle: 27% of total body Mg is in muscle but bx unpopular sampling method (ouch)
--Magnesium retention test: collect baseline 24 hour urine, analyze pre and post injection samples for Mg and creatinine, should see at lest 180 mg increase in Mg excretion in post injx urine, retention of over 25% indicates deficiency
--six macrominerals: calcium, magnesium, phosphorus, sodium, potassium, chloride
MANGANESE
--high in pts with ALS
--also assoc w/ violent behavior, dt dopamine/serotonin depletion
--whole blood is specimen of choice, reflects soft tissue levels
--analysis difficult dt low levels
--use hair to screen for toxicity but no good for noting def
MERCURY
--2-3x more in dentists & dental helpers, those with amalgam fillings, fish eaters
--correl w/ CV and AI dz
--better reflection of methylated than elemental
--higher in MS pts
--not excreted as effectively when calcium levels are high in hair
--heavy: arsenic, aluminum, antimony, cadmium, lead, mercury, nickel, uranium
NICKEL
--both necessary nutrient and heavy metal???
--from industry and smoking
-->leads to immune dysfx and CV dz
--heavy: arsenic, aluminum, antimony, cadmium, lead, mercury, nickel, uranium
POTASSIUM
--RBC content indicates tissue content and is good indicator of total body stores
--serum is routinely measured but levels don't correl with body stores (K+ is intracellular)
--low serum K indicates severe intracellular deficit
--six macrominerals: calcium, magnesium, phosphorus, sodium, potassium, chloride
RUBIDIUM
--rubidium: HAIR LEVELS REFLECT INTAKE AND tissue status
--therapy for cancer and manic depression
--Hopi'S CANCER RATE 1/1000
SELENIUM
--hair test gives good reflection of dietary intake and sufficiency
--selenium required for glutathione peroxidase, thyroid
--low se assoc w/: lung, breast CA, may reflect iodine def and hypothyroid
--RBC content also good choice
SULFUR
--must have it for hair growth, in aa's cysteine, cystine, taurine, methionine
--low if not enough good prot intake or malabsorption
--will cause insufficiency of phase II biotransformation sulfation rxns
URANIUM
--from envir
--no specific disease states according to notes
--heavy: arsenic, aluminum, antimony, cadmium, lead, mercury, nickel, uranium
VANADIUM
--elevated with bipolar disorder, normalize with tx
ZINC
--elevated dt maldistrib
--sudden zinc def-->arrest hair growth
--high zinc and low copper indic mercury displacement
--high zinc correl with high chol
--decreased in hair: prolonged def, mb dt dietary def, anorexia, vegetarian, hyperactivity, age, atherosclerosis, poverty, hypogeusia (loss of taste sense), IDDM, beta-thallassemia
--give ZnSO4 solution with 2.3 mg/10ml (2 TBS), hold in mouth 10 secs, lack of or delayed test suggests def (hypogeusia is sx of zinc def), immediate taste suggests adequate zinc