Micronutrident disorders are common and a major cause of morbidity in all populations. In this presentation we discuss the importance of iodine, folic acid and vitamin D deficiency. Prevention is the solution
5. Iodine Deficiency Disorders
Thyroid
Thyroid autonomy
Nodular thyroid
disease
Goitre
Thyroid Malignancy
Brain
Endemic cretinism
Deafness
Subclinical deafness
intellectual disability
?Attention deficits
? Colour perception
deficits
Iodine Deficiency Disorders (IDD)Iodine Deficiency Disorders (IDD)
1000 million people at risk for the1000 million people at risk for the
development of IDDdevelopment of IDD
6. Iodine Deficiency Disorders
Iodine Deficiency Disorders (IDD) refers to all of
the ill effects of iodine deficiency in a population
that can be prevented by ensuring that the
population has an adequate intake of iodine
Iodine deficiency at critical stages during
pregnancy and early childhood results in
impaired development of the brain and
consequently in impaired mental function.
12. Early recognition of goitre with impaired
mental ability
"Hence while travelling in a
certain region in the County
Tyrol, under the jurisdiction of
the Bishop of Gurk, I was
astonished at the very large
number of madmen, fools and
dolts; but when I considered
the frigidity and the humidity of
the air, and also perceived the
crudity of the waters from the
very frequent occurrence of
goitre... all astonishment
ceased entirely."
EUSTACHIUS RUDIUS, A
PHYSICIANFRO MUTRECHT
(1 551 -1 6 1 1 )
13. Endemic Cretinism
Occurs in areas of
severe iodine
deficiency and almost
universal endemic
goitre
Geographic clustering
Two predominant
clinical phenotypes
19. Are iodine levels falling?
Figure 1. (A) Median U.S. urinary iodine concentrations in
males and females, 1971-2002 (B) Median U.S. urinary
iodine concentrations in pregnant and non-pregnant women
of child-bearing age (15- 44 years old), 1971-2002.
[Adapted from Hollowell et al, JCEM 1998; 83:3401-8 & Caldwell et al,
Thyroid 2005;15:692-9]
25. NINS study
Overall, children in mainland Australia are borderline
iodine deficient, with a national median UIE of 104
mcg/L.
On a state basis, NSW and Victorian children are mildly
iodine deficient, with median UIE levels of 89 mcg/L and
73.5 mcg/L, respectively. South Australian children are
borderline iodine deficient, with a median UIE of 101
mcg/L.
Both Queensland and Western Australian children are
iodine sufficient, with median UIE levels of 136.5 mcg/L
and 142.5 mcg/L, respectively.
There was no significant association between UIE and
thyroid volume.
27. What is normal intake?
Too little and Too much can be a
problem
28. ENDEMIC GOITRE IN CENTRAL CHINA CAUSED BY
EXCESSIVE IODINE INTAKE
Thyroid status was examined in children from two
villages in China where the iodine concentrations in
drinking water were 462.5 and 54 μg/1
Goitres were present in 65% (n = 120) and 15.4%
(n=51), respectively.
Children from the high-iodine village had a lower mean
serum triiodothyronine and higher serum free thyroxine
and serum thyroid-stimulating hormone concentrations
than the children from the control village. 2 cases of
overt hypothyroidism were detected in the high-iodine
village.
29. TOPICAL IODINE-CONTAINING ANTISEPTICS AND NEONATAL
HYPOTHYROIDISM IN VERY-LOW-BIRTHWEIGHT INFANTS:
P. Smerdely, S. C. Boyages, et al. Lancet 1989
The thyroid function of very-low-birthweight (VLBW; below 1500 g) infants
admitted to neonatal intensive-care units was studied at two hospitals; one
routinely used topical iodinated antiseptic agents and the other used
chlorhexidine-containing antiseptics.
Serial Urinary iodine excretion rose dramatically in the 54 iodine-exposed
infants and was up to fifty times greater than in the 29 non-exposed infants.
Within 14 days, 25% (9 of 36) of the infants exposed to iodine had serum
thyrotropin levels above 20 mIU/l, compared with none of the control group.
The mean serum thyroxine level in these 9 infants (44·1 nmol/l) was
significantly lower than that in exposed infants with normal thyrotropin levels
(83·1 nmol/l) and in the non-exposed control group (83·0 nmol/l), thyroxine
levels fell before serum thyrotropin rose.
33. Sources of folate intake
Folate
sources
Folate
Folic acid
(FA)
Dietary Folate Equivalents
(DFE)
Food (natural) + - 1 DFE = 1 μg food folate
Food (fortified):
ECGP + RTE
cereals
+ +
1 DFE = 1 μg food folate or 0.6 μg
FA from fortified food
Supplements - +
1 DFE = 0.6 μg FA taken with food
or 0.5 μg FA on empty stomach
34. Association of folate with health outcomes
• NTD’s and other birth defects
• Cardiovascular disease
• Cognition
• Cancer
• Acceleration of cancerous growth
• Masking of vitamin B12 deficiency
• Twinning
• Immunity
• Epigenetic changes
Cause and
effect has not
been proven
Potential
adverse
effects; basis is
observational
data
Proven effectiveness of
folic acid intervention
35. Monitoring of the impact of folic acid fortification
Changes in
dietary intake
Changes in blood
levels
Changes in NTD
rates
Folic acid
fortification
policy
Changes in other
health outcomes
Benefits Risks
anes
36. Changes in biomarker levels of folate status
How much did folate blood
levels change after the
introduction of fortification?
What are the challenges
associated with assessing
folate status through
biochemical measurements?
37. Serum folate levels have nearly tripled
• Serum folate levels have
increased much more than
expected from FDA intake
modeling and short-term FA
supplementation trials –
demonstrating the value of
biomonitoring.
• Post-fortification serum folate
levels have stabilized after
several years.
http://www.cdc.gov/nchs/data/databriefs/db06.htm
http://www.cdc.gov/nutritionreport
38. Prevalence of low RBC folate levels has decreased
Red blood cell folate levels have also stabilized after fortification
and the prevalence of low levels in women of childbearing age
was ~5% compared to ~40% at pre-fortification.
http://www.cdc.gov/nchs/data/databriefs/db06.htm
RBC folate <140 ng/mL
39. Folate dietary intake data
Strengths Challenges
Non-invasive Self-reported data; flawed with
multiple errors
Relatively easy and inexpensive to
conduct
Various sources of intake need to
be captured
Easier to compare between
countries
Computation of data is complex
(DFE)
Requires two 24-h dietary recalls to
calculate usual intakes
42. Health benefits of vitamin D
Low 25(OH)D levels linked to
Osteoporosis and osteopenia
Cancer
Diabetes
Cardiovascular disease
Autoimmune disease
Multiple sclerosis
Respiratory Illness
Mental Health
43. Adequate vitamin D status
Vitamin D (nmol/L*)
Conventional
guidelines
Newer
recommendations+
Severe Deficiency <12.5
Moderate deficiency 12.5-25
Mild deficiency 25-50 <50
Insufficiency 50-75
Sufficiency >50 >75
*2.5 nmol/L = 1 ng/ml
+
Bischoff Ferrari, AJCN 2006
45. 46974697
31131 25(OH)D assays
1 July 2008 and 30 July 2010
31131 25(OH)D assays
1 July 2008 and 30 July 2010
Primary test, complete data available for
gender, age, patient setting, date of test,
postcode**, known breast cancer case,
25(OH)D ≤400 nmol/L
Sample type
1083910839 1397913979
Diagnostic referral
Outpatient
Private outpatient
Emergency
Inpatient
Private hospital
patient
Public hospital
patient
Private patient
2951629516
2481924819
Yes
680668061801218012
Female Male
6201620162516251
Summer Winter
6121612162456245
Autumn Spring
16151615
QC sample
Research
Miscellaneou
s
Unknown
* *Matched
to ARIA,
SEIFA,
Latitude,
Longitude
56. Vitamin D intake
recommendations
*Recommendations based on maintaining serum vitamin D > 75 nmol/L
(30ng/ml)
Recognition that individuals who are obese or on certain medications be
give 2-3 times more vitamin D
40 IU = 1 µg
Age NHMRC IOM US Endo
Society*
0-1 200 400 1000
1-18 200 600 1000
19-49 200 600 1500-2000
50-69 400 600 1500-2000
70 and over 600 800 1500-2000
57. Health Implications
Public health messages required to address
high prevalence of vitamin D deficiency
Australians are not adequately supplementing -
suitable guidelines are required
Implications regarding frequency and timing of
testing
59. Food Fortification
Eradication of iodine deficiency has always the highest priority.
Optimal prevention of thyroid disease by modification of iodine
intake in the population is achieved by keeping iodine intake in
individuals within a relatively narrow interval around the
recommended level.
To run an optimal iodization program it is necessary to have
information on dietary habits in the population, and on iodine
contents of different food items.
Iodine used for enrichment of food should be well distributed in
different food items, e. g. by universal or nearly universal iodization
of salt. Optimal methods may differ between European countries
depending on dietary habits.
60. Risks of iodisation programmes
Sudden increase in the prevalence of
hyperthyroidism
Jod Basedow phenomenon
Development of hypothyroidism in those with
pre-existing autoimmune thyroid disease
Positive anti-TPO antibodies
Change in the pattern of thyroid disease, rise in
the prevalence of thyroid autoimmunity
61. CONCLUSION
Thyroid hormone is essential for normal
somatic and neurological development.
Iodine deficiency leads to thyroid hormone
deficiency at critical periods of brain
development that leads to irreversible
neurological damage.
Prevention of iodine deficiency is essential
62.
63. Acknowledgements
Australia
CJ Eastman
JP Halpern
John K Collins
Li Mu
China
Indonesia
The Netherlands
Hemmo Drexhage
USA, Atlanta
GF Maberly
Italy, Pisa
Alessandro Antonelli
Editor's Notes
DFE = Dietary folate equivalents; adjusts for the nearly 50% lower bioavailability of food folate compared with that of folic acid
1 ug FA from fortified food or supplements equals 1.67 DFE
For NTD’s randomized controlled trials have proven the effectiveness of folic acid supplementation in reducing the risk to have an offspring affected with a neural tube defect.
However, low folate levels have been associated with many other health outcomes including: cardiovascular disease, cognition and dementia, and various cancers.
These associations are primarily based on ecologic or observational data.
The cause and effect has not been proven for most of the associations.
At the same time, excessive amounts of folate, and we currently don’t have a good definition of what “excessive” means, have been associated in some cases with adverse effects, such as masking of vitamin B12 deficiency, twinning, immunity, and possibly epigenetic changes.
You can therefore imagine how important careful monitoring of the impact of folic acid fortification becomes.
Changes in blood levels and in dietary intake are monitored through NHANES, while there are other surveillance systems to monitor changes in NTD rates and other health outcomes.
Before implementing folate fortification, FDA intake modeling estimated that low consumers would increase their folate intake by 80-100 g per day.
Short-term FA supplementation trials showed that serum folate levels increased by approximately 20-30% in response to a 100 g per day increase in FA intake.
No information was available on the magnitude of changes in blood folate levels as a result of continuous daily exposure to FA from fortified food products.
By applying the same laboratory method (BioRad RIA) – held to strict quality assurance requirements to ensure comparability of data over time – to post-fortification blood samples as was used pre-fortification, we showed that folate status has greatly improved in the entire U.S. population as well as in the target group of women of childbearing age.
Moreover, serum folate levels increased much more than expected from short-term FA supplementation trials - they nearly tripled.
This demonstrates the value of biomonitoring, as it reflects the net effect of a number of uncertainties surrounding public health decisions such as fortification (i.e., underreporting of foods consumed, increased consumer selection of folate-rich foods because of health claims, and increasing availability of the numbers and types of folate-fortified nonstandardized foods).
Short-term FA supplementation trials showed that RBC folate levels increased by approximately 10% in response to a 100 g per day increase in FA intake.
RBC folate levels increased much more than expected from short-term FA supplementation trials – they nearly doubled, again demonstrating the value of biomonitoring.
As part of a more specific study we are conducting to understand the relationship between vitamin D status and factors associated with breast cancer prognosis we wanted to assess vitamin D status in the a large population of individuals in and examine the relationship between vitamin D and other environmental factors.
Australian studies to date have been limited. Most have sample sizes or examine vitamin D status in individuals at high risk of deficiency.
Sunlight 1 MED = 20000 IU
Hands, arms, neck (11%) for 20 minutes in summer early am = 1000 IU
Salmon 160g fillet approx. 530 IU
Fortified cheese slice 55 IU
Regular milk 20 IU
Margarine 12 IU
Multivitamins ave.200 IU
Caltrate with D 400 IU
Specific D ave. 1000IU
Current recommendations generally focus on bone health in older people. Evidence suggests that vitamin D intakes above current recommendations may be associated with better health outcomes although the optimal level is not known.
The most advantageous serum concentrations of 25(OH)D of 75nmol/L (30ng/mL) are based on factors such as reduction in fractures rates, maximum suppression of PTH and maximum calcium absorption as well as non skeletal outcomes.
An intake of at least 1000 IU is suggested to bring at least 50% of the population up to 75nmol/L
Australian studies have included limited numbers of subjects.
Study Design
Explain patient status
Define setting
Aria; SEIFA. latitude obtained from postcode
Based on visual inspection of vitamin D level by age we classified subjects into age groups: &lt;20; 20-39. 40-59, 60-79, ≥80
Inpatients always lower than ambulatory subjects except females in very remote Australia.
The annual benefit for 25OHD testing subsidised by the MBS increased from $1.02 million in 2000 to $96.7 million in 2010, an average increase of approximately 59% per year
This increase in 25OHD testing has risen above the general trend of other common pathology tests such as full blood count
The high frequency of testing in individuals suggest that better value could be derived. Subgroup analysis between 1 April 2006 and 31 October 2010 showed that although 49.5% of individuals had an average of two tests in that period, 14.5% had over four tests, and 8.2% had over five tests (with some individuals having up to 79 tests in that period).
Based on adequate sunlight exposure
Developed for maintenance of calcium homeostasis and prevention of osteoporosis
Call for new recommendations based on newly discovered actions