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Vitamin B2 _riboflavin_

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					§ Vitamin B2 (riboflavin)
   Clinical riboflavin deficiency is rare in developed countries. The principal
dietary sources are dairy foods, meat, and riboflavin-enriched flour.
Erythrocyte glutathione reductase (ERG) assay
         ERG (with FAD)
        ERG (without FAD)
Urine riboflavin: This displays more within-person variation.
Plasma riboflavin: Oral doses of riboflavin result in a rapid transient increase
in plasma riboflavin levels with a half-life of less than 5 hours. It may not be
good indicators of long-term intake.


Copper
  Although copper-dependent enzymes and copper-containing proteins are
numerous, clinical diagnosis of copper deficiency appears to be rear,
presumably due to the wide distribution of copper in foods and cooking
utensils.
Serum and Plasma –Atomic absorption spectrophotometry (AAS)
  The relation between dietary copper intake and serum or plasma levels is
low. The reason that circulating copper levels are a poor guide to copper
status is the large number of lifestyle factors (e.g., oral contraceptive use,
smoking) and pathologic conditions (e.g., inflections and inflammation) that
profoundly alter blood copper concentration.
Ceruloplasmin
  94% of circulating copper bound to the curoprotein ceroloplasmin, and it
has suggested that this would be a more reliable measure of copper status.
Ceruloplasmin production is also influenced by many factors other than
dietary intake.
Erythrocyte Superoxidase Dismutase (SoD)
  Measurement of the function of the copper-and zinc-dependent enzyme
SoD would be a better index of copper status.
  Cytocrome c activity in leukocytes and platelets is reduced in copper
deficiency before SoD activity is reduced and may be a useful marker of early
copper deficiency.
Hair -neutron activation analysis or AAS
  It is not be elevated in Wilson’s Disease. Be careful of external
contamination.
Nails -neutron activation analysis or AAS
  Nail levels reflect differences in normal dietary intake.
Urine
   The major excretory route for copper is bile, and only small amounts are
lost in urine. And the large day-to-day fluctuations in urinary copper excretion
make this an unreliable indicator of long-term copper status.
-Amino acids appear to increase copper absorption.
-Ascorbic acid, fiber, zinc appear to decrease copper absorption.
   Collection of info about all of these factors should theoretically aid in the
interpretation of measures of copper status.

§ Folacin and folic acid


Introduction:
      The principal dietary sources of folacin are leafy vegetables, fruits,
fortified cereals, and tea.
    as coenzymes in the metabolism of single-carbon compounds
    the methyl donor in the conversion of homocysteine to methionine


Folate deficiency:
1. megaloblastic anemia
2. neural tube defects in infant
3. related to heart disease and colorectal cancer.


Measure:
    The most commonly employed assays of folacin nutriture are serum and
red blood cell folate level.
   Serum levels: after 3 weeks in a low folate diet, serum folate level decline
   Red blood cell: in the normal range for approximately 17 weeks
   Polymorphonuclear leukocyte lobe counts


Method:
1. Microbiologic assay
   This assay, using the growth dependency of Lactobacillus casei on folacin,
   is regarded as the standard procedure for folacin measurement in biologic
   specimens.
2. Radiodilution assay
   A variety of radiodilutables exist in commercial kit form


Storage:
    The effect of storage on measures of folacin status is uncertain.


Measurement of other determinants:
Folate level reduced: in smorker, pregnant or highly parous women (three live
birth)
Alcohol and prescription drug may antagonize folacin absorption.
Folate level increase: in multivitamin supplement users

				
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