Journal of Thyroid Research

Review Article

The Hypothalamic-Pituitary-Thyroid Axis in Infants and Children: Protection from Radioiodines

Table 2

Radioactive iodide uptake into the thyroid gland (RAIU, expressed as percent of the administered radioactive dose) and thyroidal and renal clearance rates of iodide in infants, children, and adults.
RAIU study24 hr RAIU
% of dose
mean		24 hr RAIU
% of dose
range		Number of volunteersLocationReference
Infant and child age     
 2 months to 18 years31.117 to 5060United States[9]
 9 to 18 years, hyperthyroidism8772 to 995United States[9]
 Newborn, 2-3 days, 14a hr RAIU69.7a46 to 97a7United States[10]
 Premature (2 lb, 4 oz to 5 lb 15 oz)38.628 to 5216United States[11]
 2 years —15–235United States[12]
 9 to 15 years52.928–5226Belgium[13]
 1.5 to 2 years (euthyroid)39.6 6Republic of Senegal[14]
 1.5 to 2 years (malnutrition)23.9 12Republic of Senegal[14]
 7 to 9 years23.521 to 254United States[15]
Adults     
 Euthyroid32.216 to 5064United States[9]
 Hyperthyroid76.134 to 10062United States[9]
 23 to 50 years20.017.2 to 21.822United States[16]
 Unknown41.7 unknownBelgium[13]
 25 to 46 years24.810–47.827Germany[17]
 18 to 57 years20.0SE 1.5 to 3.837United States[18]
 Mean
(mL/min)		Mean
(mL/min/kg)		Number of VolunteersLocationReference
Thyroidal clearance of iodide     
 Children     
  Birth to 3 weeks —2.523Belgium[19]
  3 weeks to 6 months—1.094Belgium[19]
  6 to 12 months—0.97Belgium[19]
  1 to 2 years—1.77Belgium[19]
  9 to 15 years, normal30.30.8026Belgium[13]
  Normal 21.5—6Republic of Senegal[14]
  Malnourished7.3—12Republic of Senegal[14]
 Adults 25.30.35unknownBelgium[13]
Renal clearance of iodide     
 Children     
  Birth to 3 weeks —0.743Belgium[19]
  3 weeks to 6 months—1.14Belgium[19]
  6 to 12 months—0.737Belgium[19]
  1 to 2 years—1.57Belgium[19]
  9 to 15 years25.50.6526Belgium[13]
 Adults29.70.41—Belgium[13]
Refers to a 14 hr RAIU value, which is different than all others, which are in the column with a header stating 24 hr RAIU.