Iodine: Dosage. Toxicity

Dosage Range

AMERICAN AND AUSTRALIAN RDI

• Infants

  • 0-6 months: 90 µg/day
  • 7-12 months: 110 µg/day

• Children

  • 1-3 years: 90 µg/day
  • 4-8 years: 90 µg/day
  • 9-14 years: 120 µg/day
  • >14 years: 150 µg/day

• Adults: 150 µg/day

Pregnancy: 220 µg/day

Lactation: 270 µg/day

• Upper level of intake

  • 1-3 years: 200 µg/day
  • 4-8 years: 300 µg/day
  • 9-13 years: 600 µg/day
  • 14-18 years (including pregnancy, lactation): 900 µg/day
  • Adults >18 years (including pregnancy, lactation): 1100 µg/day

These are the newly revised American and Australian RDIs, which are more closely aligned with the WHO recommendations than previously.

ACCORDING TO CLINICAL STUDIES

• ADHD prevention: adequate intake to prevent maternal deficiency (approximately 250 µg/day).

• Fibrocystic breast disease and cyclic mastalgia: 500 µg to 6 mg molecular iodine/day.

• Breast cancer prevention: dose is unknown; however, it is suggested that women meet RDI to prevent deficiency.

• Water disinfectant: 3-5 ppm in water or 8 drops of 2% tincture to approximately 1 L of water.

Toxicity

Chronic iodine toxicity results when iodide intake is approximately 2 mg daily or greater. Overconsumption of iodine can induce both hypo- and hyperthyroidism, depending on the patient’s pre-existing susceptibility. Excess iodine during pregnancy has also been associated with increased risk of postpartum thyroiditis. Alternatively, there are many cases in which excesses have been tolerated without any overt consequences. Intake of very high doses can lead to a brassy taste in the mouth, increased salivation, gastric irritation and acneiform skin lesions.