Iodine for Radioprotection
Verdict: Published with Warning
Across 5 PubMed studies, the evidence for Iodine in Radioprotection grades Tier A — moderate evidence. Effective, but with safety or population caveats.
A 🔵 A Moderate Evidence Published with Warning
Why this grade7-layer evidence engine
⚖️
Scoring transparency
All scores computed by a 7-layer evidence engine — fully auditableRaw score 0.76
D
C
B
A
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← counter-evidence / ineffectiveeffective / strong evidence →
Final grade
A · Published with Warning
Confidence
92%
Highly consistent evidence
Evidence level
E2
Multiple high-quality MAs (≥2 independent, consistent)
▸View the full decision path (audit trail)
- compute_raw_score — 加權公式: L2×0.30 + L3×0.25 + L5×0.25 + L11×0.10 + L1×0.10 = 0.76
- tier_from_score — 依分數區間映射至 tier letter
- apply_hec_rules — 無高階證據可裁決
- tier_strict_requirement_check — Tier 條件達標，未降階
- detect_disputes — 偵測到 0 個 hard + 0 個 soft dispute
- decide_status — 依 tier + dispute 結果決定 status
PubMed studies (5)L2 · primary research & systematic reviews
The effects of iodine blocking on thyroid cancer, hypothyroidism and benign thyroid nodules following nuclear accidents: a systematic review
Finding: Pooled 4 observational studies (1 cross-sectional, 1 cohort, 2 case-control; participant range 886–12,514, mostly children); meta-analysis was impossible due to heterogeneity, and only low to very-low-quality evidence suggested KI may reduce thyroid cancer in children, with no conclusion drawable for hypothyroidism or benign nodules.
View on PubMed Adverse effects of iodine thyroid blocking: a systematic review
Finding: Across 14 articles (only one assessing ITB adverse effects directly, post-Chernobyl) no severe adverse reactions to KI were observed in the general public, but the authors concluded the evidence base is weak because sound adverse-effect studies are scarce.
View on PubMed Review of the PRIODAC project on thyroid protection from radioactive iodine by repeated iodide intake in individuals aged 12+
Finding: This narrative program review of the PRIODAC project (efficacy/safety data are preclinical rat studies plus pharmacokinetic modeling, not a human trial) established an optimal regimen of one 65 mg KI tablet daily for up to 7 days, which supported a new French marketing authorization for repeated iodine thyroid blocking.
View on PubMed Do multiple administrations of stable iodine protect population chronically exposed to radioactive iodine: what is PRIODAC research program (2014-22) teaching us?
Finding: This narrative review presented only preliminary PRIODAC program data and stated literature aims (side effects of repeated KI, iodine metabolism, dose revision, international harmonization), reporting no specific quantitative efficacy results.
View on PubMed Thyroid blockade during a radiation emergency in iodine-rich areas: effect of a stable-iodine dosage
Finding: In a small open-label dose-comparison in 8 hyperthyroid patients in iodine-rich Japan, single oral doses of 38 mg and 76 mg iodide both significantly suppressed 24-hour thyroid uptake (73.3% vs 79.5% protection; p=0.03), with the lower dose equivalent to the higher.
View on PubMed Regulatory & authoritative positionsL4/L5 · FDA / EMA / NIH ODS / Cochrane / Mayo …
L4a US FDA
Supportive
Iodized salt or iodized table salt is the article of commerce, salt for human food use, to which has been added cuprous iodide or potassium iodide. The label shall bear the statement 'This salt supplies iodide, a necessary nutrient'. Cuprous iodide and potassium iodide may be added to table salt as a source of dietary iodine in an amount not greater than 0.01 percent. source↗
L4b EU EFSA
Supportive
Iodine contributes to normal cognitive function, normal functioning of the nervous system, the maintenance of normal skin, normal production of thyroid hormones and normal thyroid function, and contributes to normal growth of children source↗
L4c UK NHS
Cautious
Adults need 140 micrograms (μg) of iodine a day. Most people should be able to get all the iodine they need by eating a varied and balanced diet. Taking high doses of iodine for long periods of time could change the way your thyroid gland works. This can lead to a wide range of different symptoms, such as weight gain. Taking 0.5mg or less a day of iodine supplements is unlikely to cause any harm. source↗
L4d TW TFDA / 衛福部
Supportive
孕婦碘的每日建議攝取量為225微克，較一般成人140微克高出許多；衛生福利部建議孕婦及哺乳婦使用加碘鹽，並可適量攝取含碘量豐富的食物，如海帶、海藻類等。 source↗
L4e WHO
Supportive
All food-grade salt, used in household and food processing should be fortified with iodine as a safe and effective strategy for the prevention and control of iodine deficiency disorders in populations living in stable and emergency settings. source↗
L5a NIH Office of Dietary Supplements
Supportive
Iodine is a mineral found in some foods. The body needs iodine to make thyroid hormones. These hormones control the body's metabolism and many other important functions. The body also needs thyroid hormones for proper bone and brain development during pregnancy and infancy. source↗
L5b Mayo Clinic
Supportive
Potassium iodide is used to protect the thyroid gland from the effects of radiation from radioactive forms of iodine. It may be used before and after administration of a radioactive medicine containing radioactive iodine or after accidental exposure to radiation (for example, from nuclear power plant accidents). When taken at the appropriate dosage and within the correct time interval around ex… source↗
L5c Cleveland Clinic
Supportive
It fills up your thyroid with enough iodine to keep it busy for a while. So, instead of absorbing the radioactive iodine, your thyroid ignores it. In radiation emergencies, one dose typically protects you for about 24 hours. So, most people should take one dose per day until local officials say it's safe to stop taking it. Potassium iodide only protects your thyroid from radioactive iodine (one… source↗
L5d Harvard Health
Supportive
Because KI contains so much stable iodine, the thyroid gland becomes 'full' and cannot absorb any more iodine—either stable or radioactive—for the next 24 hours. Children and infants are more vulnerable to developing thyroid cancer from radioactive iodine than adults, so it's important that they get the pills in a radiation emergency. Large doses of iodine over a long period of time can be dang… source↗
L5e Specialty Society (condition-mapped)
Supportive
KI is a type of iodine that is not radioactive. It can be used to help block one type of radioactive material, radioactive iodine, from being absorbed by the thyroid. KI is only recommended for people under 40 and women who are pregnant or breastfeeding. Do not take KI unless instructed by public health or emergency response officials or a healthcare provider. One dose of KI offers protection f… source↗