What kind of interaction is it?

Timing-sensitive: the two substances can be taken on the same day but should be separated by a minimum time window.

Is this interaction backed by published research?

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

Supplement × Prescription·timing-sensitive·Insufficient evidence

Calcium + Penicillin V Potassium

Q: Can I take Calcium and Penicillin V Potassium together?

Yes, if you separate them in time. Calcium and Penicillin V Potassium have a documented timing-sensitive interaction. Calcium is a divalent cation that can theoretically bind some oral antibiotics in the gut. For penicillin V the effect on absorption is minimal, but spacing calcium supplements from antibiotic doses is a reasonable general practice and prevents confusion with antibiotics where the interaction is significant.

Q: How does this affect a NutriStack Stack Score?

-5 to your Stack Score per scored timing-sensitive row.

Timing Sensitive Insufficient evidence

Calcium is a divalent cation that can theoretically bind some oral antibiotics in the gut. For penicillin V the effect on absorption is minimal, but spacing calcium supplements from antibiotic doses is a reasonable general practice and prevents confusion with antibiotics where the interaction is significant.

Supplement × Prescription

Open the interaction checker → Read the methodology

From the database

What the row says.

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

Substances

Calcium and Penicillin V Potassium

Pair type

Timing Sensitive

Evidence

Insufficient

Source citations

Scope

Supplement × Prescription

Last verified

June 4, 2026

Timing SensitiveInsufficient evidence

What is happening. Calcium is a divalent cation that can theoretically bind some oral antibiotics in the gut. For penicillin V the effect on absorption is minimal, but spacing calcium supplements from antibiotic doses is a reasonable general practice and prevents confusion with antibiotics where the interaction is significant.

Mechanism. Divalent calcium can form chelation complexes with susceptible antibiotic molecules, reducing their luminal absorption; penicillins have low affinity for this interaction so any absorption reduction is expected to be clinically insignificant.

Recommendation. Separate calcium supplements and calcium-rich antacids from penicillin V doses by about 2 hours as a low-priority precaution. Penicillin V absorption is best on an empty stomach. The strong calcium-chelation interaction applies to tetracyclines and fluoroquinolones, not to penicillins.

Timing

Timing & separation.

Space the doses apart by at least this window to avoid the conflict.

Minimum separation

120

Stack Score

How it moves the number.

Effect on the composite score

If both Calcium and Penicillin V Potassium are in the same stack, this pair applies −5 to your Stack Score (per scored timing-sensitive row).

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

Sources

Sources, by evidence tier.

Every claim on this page is cited. PMIDs link straight to PubMed.

Reference material

1Neuvonen PJ. Interactions with the absorption of tetracyclines. Drugs. 1976.Needs sourceNo link
2Penicillin V Potassium prescribing information. Administration with food and minerals. Manufacturer label. Current edition.Needs sourceNo link

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