The Future of Reference Materials - Science and Innovation 23 - PowerPoint PPT Presentation

Reference Materials for the Nutrition Community The Future of Reference Materials - Science and Innovation 23 November 2010 Joseph M. Betz 1 , Mary Frances Picciano 1 , Karen Phinney 2 1 Office of Dietary Supplements, National Institutes of Health 2 National Institute for Standards and Technology

NIH is the Nation’s Medical Research Agency www.nih.gov OFFICE OF DIETARY SUPPLEMENTS 2

Reference Materials and ODS ODS Analytical Methods and Reference Materials Program- multi-year project with NIST • “Suites” of Standard Reference Materials – Supplement raw materials & finished products – Certified and Reference values for marker compounds, nutrients, contaminants • Calibration Standards www.nist.gov
 OFFICE OF DIETARY SUPPLEMENTS 3

Outcomes In Process 
 Available • St.
John’s
wort
 • Botanical
oils
(tocopherols)
 • Soy
 • Fish
oil
(FAs,
tocopherols)
 • Black
cohosh
 • Ginkgo
 • Kudzu
 • Bi:er
orange
 • Red
clover
 • Saw
palme:o
 • Turmeric
 • Mul?vitamin/mineral
tablets
 • Pomegranate
 • Botanical
&
fish
oils
(Ω3’s,
6’s)
 • Ginsengs
(Asian,
Siberian)
 • Green
tea
 • Berries
 • Vit.
D
in
human
serum
 OFFICE OF DIETARY SUPPLEMENTS 4

NIST SRM for Nutrition (available prior to ODS program) Foods
with
values
assigned
for
nutrients
(proximates, 
 vitamins,
carotenoids,
elements,
fa:y
acids,
amino
 acids
as
appropriate)
 • SRM
1849
Infant/Adult
Nutri?onal
Formula
 • SRM
1946
Lake
Superior
Fish
Tissue
 • SRM
2384
Baking
Chocolate
 • SRM
2385
Slurried
Spinach
 • SRM
2387
Peanut
Bu:er
 • SRM
3287
Blueberry
(Fruit) 
 plus
5
more
in
progress 
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NIST SRM for Nutrition • 909c‐Glucose,
urea,
uric
acid,
cholesterol,
crea?nine,
total 
 
protein,
electrolytes
 • 968e‐Fat‐Soluble
Vitamins,
Carotenoids,
Cholesterol,
 
tocopherols,
re?nol,
beta‐carotene
 • 2670‐Toxic
Elements
in
Urine:
14
elements
 • 3950‐Vitamin
B 6 
in
Human
Serum
 • 3951‐Vitamin
B 12 
in
Human
Serum
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Case
Study:
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Vitamin D Status of the US Population? OFFICE OF DIETARY SUPPLEMENTS 8

25(OH)D Assay Concerns (Looker et al., 2008) • 1988-94 vs. 2000 - 2004: − Reformulation (introduction of antibody to improve binding) of RIA assay kit  shifts in assay results between these two time periods − Adjusted for assay drifts to compare time trends in 25(OH)D and identify contributing factors Looker
et
al.

Am
J
Clin
Nutr
2008;88:1519‐27.
 OFFICE OF DIETARY SUPPLEMENTS 9

Adjustment Affects Policy Conclusions • Adjustments for assay differences: − Looker et al. (2008): • Overall mean 25(OH)D lower in 2000-2004 than in 1988-94 • Assay changes accounted for much of the difference • No adjustment for assay differences: − Ginde et al. (2009) : • Marked decrease in 25(OH)D in 2000-2004 from 1988-1994 • Growing epidemic of vitamin D insufficiency − Saintonge (2009): • Vitamin D deficiency is increasing from 1988-1994 to 2006 • National fortification and public health strategy OFFICE OF DIETARY SUPPLEMENTS 10

NIST SRM- July 2009 • 
SRM
972‐
Vitamin
D
metabolites
in
Human
Serum
 − Suite
of
four
1.0
ml
vials
with
cer?fied
and
reference
 
values
for
25(OH)D 2 ,
25(OH)D 3 ,
and
3‐epi‐25(OH)D 3 
 • SRM
2972‐
25(OH)D 2
 &
25(OH)D 3 
Calibra?on
Solu?ons
 − SRM
2972
is
a
set
of
ethanolic
calibra?on
solu?ons
and
 
has
cer?fied
values
for
25(OH)D 2 
and
25(OH)D 3
 • Value
assignment
by
isotope‐dilu?on
LC‐MS
and
LC‐MS/MS
 • RM
drives
science‐
previously
thought
3‐epi
only
occurred
 
in
infants
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• Ques%ons
about
equivalence
of
LC/MS
assay
response
to
 25(OH)D 2 
and
25(OH)D 3
 
 − Immunoassays
measure
“total”
25(OH)D
 − Older
LC/MS
methods
did
not
resolve
3‐epimer 
 • 3‐epimers
of
25(OH)D
may
bias
MS‐based
methods
 25(OH)D 3
 3‐epi‐25(OH)D 3
 OFFICE OF DIETARY SUPPLEMENTS 12

NIST LC-MS Methodology for 25(OH)D 25(OH)D 2
 25(OH)D 3
 3‐epi‐25(OH)D 3
 25(OH)D 2 ‐[ 2 H 3 ] 
 25(OH)D 3 ‐[ 2 H 6 ] 
 Tai
et
al.
(2010)

Anal
Chem
82:1942‐1948
 OFFICE OF DIETARY SUPPLEMENTS 13

Level
1
 65
±
15
nmol/L
25‐hydroxyvitamin
D 3 
(“normal”)
 Level
2
 Blend
of
“normal”
serum
and
horse
serum
to
obtain
 approximately
half
the
level
of
25‐hydroxyvitamin
D 3 
in
the
 “normal”
pool
(35
±
5
nmol/L)
 Level
3
 “Normal”
serum
spiked
with
equivalent
amount
of
25‐ hydroxyvitamin
D 2
 Level
4
 “Normal”
serum
spiked
with
3‐epi‐25‐hydroxyvitamin
D 3
 OFFICE OF DIETARY SUPPLEMENTS 14

Commutability
is
defined
as
the
equivalence
of
the
 mathemaZcal
relaZonships
between
the
results
of
different
 measurement
procedures
for
a
reference
material
and
for
 representaZve
samples
from
healthy
and
diseased
individuals.

 Vesper
et
al.,
Clin.
Biochem.
Rev.,
28
(2007)
139
 Reasons
a
reference
material
may
not
be
commutable:
 • Material
handling,
processing
(lyophiliza?on,
filtering,
etc.)
 • Supplementa?on
with
na?ve
or
non‐na?ve
analytes
 • Differences
between
samples
from
healthy
and
diseased
 individuals
 OFFICE OF DIETARY SUPPLEMENTS 15

Other
RM
needs
 Marketed
products‐matrices
 • Delayed
release
dosage
forms‐
ion
exchange
 resins,
etc.
 • Oil‐filled
gelcaps‐
vegetarian
and
animal
gela?n
 • Microencapsulated
materials‐
Carrageenan,
 gela?n,
etc.
 • “Nano”
ingredients
in
finished
products
 • “Unusual”
matrix
source
for
nutrients
and
 nutrient
elements‐
e.g.
iodine
in
kelp
vs
KI
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Other
RM
needs
 Clinical
materials
and
calibra?on
standards
 • Folate,
other
complex
vitamers
in
serum
for
LC/MS
 • Biomarkers
of
nutrient
exposure
vs.
markers
of
 Nutrient
status‐
e.g.
Omega‐3
fa:y
acids
in
serum
 vs.
red
blood
cell
membrane
 • Isotope
labeled
nutrients
and
metabolites
as

 calibra?on
standards
for
MS
detec?on
 • Serum
based
calibra?on
solu?ons
 Yetley
et
al.
(2010) 
J
Nutr
 140: 2030S‐2045S
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Non-RM Activities NIST Vitamin D metabolite Laboratory Quality Assurance Program & Dietary Supplement Laboratory Quality Assurance Program • NIST sends blinded material, practice sample – Participants perform analyses and return data to NIST – NIST provides feedback on blinded results, including suggestions for method optimization • To participate (no cost), send e-mail to vitdqap@nist.gov

or
DSQAP@nist.gov

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“Reference Materials are the most efficient means to transfer accuracy to a field” -John Eckfeldt, MD, Ph.D. Professor of Laboratory Medicine, University of Minnesota Medical Center OFFICE OF DIETARY SUPPLEMENTS 19

Joseph M. Betz www.ods.od.nih.gov E-mail: ods@nih.gov E-mail: betzj@mail.nih.gov http://dietary-supplements.info.nih.gov/FactSheets/AMRMProgramWebsite.asp OFFICE OF DIETARY SUPPLEMENTS 20