Compare Supplements

Side-by-side comparison of 2 supplements

I8.5

Iodine

Moderate safety

Pnv7.0

Prenatal Multivitamin

Moderate safety

Evidence

Mixed evidence

Evidence Score8.5/10

Studies: 87

Meta-analyses: 16

Mostly mechanism / observational

Evidence Score7/10

Studies: 63

Meta-analyses: 7

Outcome Verdicts

Prenatal supportLimited support

Prenatal supportLikely helps

Prenatal supportToo few graded studies

Plain-language verdict per shared outcome, pooled from the studies behind each supplement. Shows which one the evidence backs for the same goal.

Pooled effect-size head-to-headBeta

Direct side-by-side from the meta-analysis. Each row is an outcome where ≥2 of your selected supplements have pooled data. Best effect per row highlighted.

Outcome	Iodine	Prenatal Multivitamin
Prenatal support — Birth Weight + better · grams	+0.6 weak · CI ∋ 0	+38.2best weak
Prenatal support — Maternal Hemoglobin + better · g/dL	+0.4best strong	+0.4 weak

Click an outcome to see the full ranked table on the goal page.

Dosage & timing

Dosage:

220mcg

Best Time:

Morning · with food (preferred)

Take with food

Form:

Potassium iodide (most common and studied)

Dosage:

1 serving daily as labelled. The verified folic acid evidence rests on 400-800 mcg daily started before conception

Best Time:

With meals · with food

Take with food

Form:

A prenatal containing 400-800 mcg folic acid, started at least one month before conception

What you'll notice

⚖️ Thyroid Normalizationpositive

4-12 weeks

⚡ Energy Improvementpositive

4-8 weeks

🛡️ Prevents neural tube defectspositive

Requires pre-conception start

⚖️ Less low birthweightpositive

Across pregnancy

🩸 Less maternal iron-deficiency anaemiapositive

Across pregnancy

Safety

Moderate safety

Contraindications:

Hyperthyroidism
Hashimoto's (use with extreme caution)
Dermatitis herpetiformis

Drug Interactions:

Thyroid medications
Lithium
Antithyroid drugs (methimazole, propylthiouracil)

Side Effects:

Thyroid dysfunctionMetallic tasteAcne/skin breakout

Moderate safety

Contraindications:

Products supplying more than 10,000 IU/day (3,000 mcg RAE) of preformed vitamin A (retinol) in pregnancy — this is the established Tolerable Upper Intake Level for preformed vitamin A, set by the IOM/NASEM and reaffirmed by EFSA in 2024, with teratogenicity as the designated critical effect
Concurrent use of a separate high-dose vitamin A supplement or prescription retinoid
Haemochromatosis or iron overload (iron-containing products)

Drug Interactions: