| Methods |
Advantages |
Disadvatanges |
|
Median urinary iodine concentration
(μg/L) |
affordable
|
varries with the ingestion of fluids
|
|
relatively easy to collect in most population groups
|
|
important to avoid contamination
|
|
can be measured in spot urine specimens from a representative sample of the target group
|
|
does not provide direct information on thyroid function, but a low value suggests a population is at higher risk of developing thyroid disorders
|
|
can be used for all categories of people
|
|
not valuable for individual assesment
|
|
evaluate the iodine intake for the last few days
|
|
a large number of samples need to be collected because of the great variability of biological products
|
|
requires laboratory equipment and trained technicians.
|
|
Thyroid stimulating hormone
(mIU/L) |
sensitive indicator of iodine status in the newborn period
|
not useful if iodine antiseptics used at birth
|
|
minimal costs if a congenital hypothyroidism screening program is already in place
|
relatively insensitive indicator of iodine nutrition in school-aged children and adults.
|
|
simple technique
|
requires a standardized, sensitive assay
|
|
can be measured from a dried blood sample
|
|
relatively sophisticated equipment required to quantitatively measure TSH
|
|
blood spots can be collected and stored for weeks in dry rooms with low temperature
|
|
should be taken by heel-prick at least 48 hours after delivery or from the cord right after birth in order to avoid physiological newborn surge
|
|
Serum or whole blood thyroglobulin
(μg/L) |
simple technique
|
expensive immunoassay
|
|
collection of samples is easy
|
standard reference material is available, but needs validation
|
|
samples can be stored in cold, dry rooms
|
|
international reference range available
|
| well correlated with the severity of iodine deficiency as measured by UI. |
|
Can be used to measure the improvement of thyroid function within several months after iodine repletion
|
|
more sensitive indicator of iodine repletion than TSH or T4.
|
| T3/T4 |
reflects the function of the thyroid
|
poor indicators of iodine status
|
| Goiter Physical examination |
simple and quick
|
poor sensitivity and specificity
|
|
requires no special equipment
|
|
response to iodine intake appears after a long period of time
|
|
experienced examiner
|
| Goiter ultrasound |
noninvasive, quick and safe
|
requires experience and training
|
|
feasible even in remote areas using portable equipment
|
|
responds only slowly to changes in iodine intake
|
|
international reference values available
|
|
requires expensive equipment
|
