What kind of interaction is it?

Synergy: a documented combination effect that is stronger or more useful than either substance taken alone.

Is this interaction backed by published research?

Yes. NutriStack lists 2 citation rows for the Losartan + Vitamin D3 pair, each linking to PubMed by PMID where available. Full sourcing methodology at https://nutristackapp.com/methodology/interactions.

Interaction databaseSupplement × PrescriptionReviewed May 2026

Losartan and Vitamin D3, a synergy.

Q: Can I take Losartan and Vitamin D3 together?

Yes. The combination of Losartan and Vitamin D3 produces a measurable benefit. Vitamin D directly suppresses renin biosynthesis, so vitamin D deficiency leaves the renin-angiotensin system over-activated. Correcting deficiency in losartan-treated patients may modestly improve blood pressure control and reduces upstream RAAS activation that ARBs are trying to counter. The combination is well tolerated.

Q: How does this affect a NutriStack Stack Score?

+2 to your Stack Score per scored synergy row.

Vitamin D directly suppresses renin biosynthesis, so vitamin D deficiency leaves the renin-angiotensin system over-activated. Correcting deficiency in losartan-treated patients may modestly improve blood pressure control and reduces upstream RAAS activation that ARBs are trying to counter. The combination is well tolerated.

2 primary source citations. Moderate evidence. Last verified May 30, 2026.

Open the interaction checker →Read the methodology

One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.

Sourcing standards·Evidence tiers

From the interaction database

What the row says.

Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.

At a glance

Substances: Losartan and Vitamin D3
Pair type: Synergy
Evidence (highest tier): Moderate
Source citations: 2 sources
Stack Score effect: +2 to your Stack Score (per scored synergy row).
Scope: Supplement × Prescription
Last verified: May 30, 2026

Synergy · Moderate evidence

Synergy

What is happening. Vitamin D directly suppresses renin biosynthesis, so vitamin D deficiency leaves the renin-angiotensin system over-activated. Correcting deficiency in losartan-treated patients may modestly improve blood pressure control and reduces upstream RAAS activation that ARBs are trying to counter. The combination is well tolerated.

Mechanism. 1,25-dihydroxyvitamin D binds the vitamin D receptor and downregulates renin gene transcription, reducing angiotensin II generation upstream of AT1 receptor blockade. Correcting deficiency complements the pharmacologic effect of losartan.

Recommendation. If your 25-hydroxyvitamin D level is below 30 ng/mL, supplementing 1000-2000 IU/day of Vitamin D3 is reasonable, with periodic level checks. Monitor home blood pressure after starting and tell your prescriber.

Sources (2)

Stack Score

How this pair moves the number.

Effect on the composite score

If both Losartan and Vitamin D3 are in the same stack, this pair applies +2 to your Stack Score (per scored synergy row).

The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.

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