NutriStack
Calcium and Levofloxacin, timing-sensitive.
Calcium binds levofloxacin in the gut and reduces its absorption by 30 to 50 percent. This applies to calcium supplements, calcium-fortified foods, and dairy. Lower antibiotic exposure can cause treatment failure for serious infections.
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.
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
- Calcium and Levofloxacin
- Pair type
- Timing Sensitive
- Evidence (highest tier)
- Strong
- Source citations
- 2 sources
- Stack Score effect
- −5 to your Stack Score (per scored timing-sensitive row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Timing Sensitive · Strong evidence
Timing Sensitive
What is happening. Calcium binds levofloxacin in the gut and reduces its absorption by 30 to 50 percent. This applies to calcium supplements, calcium-fortified foods, and dairy. Lower antibiotic exposure can cause treatment failure for serious infections.
Mechanism. Ca2+ cations chelate the 3-carboxyl and 4-oxo groups on levofloxacin, forming insoluble complexes in the intestinal lumen that are not absorbed.
Recommendation. Take levofloxacin at least 2 hours before or 2 hours after calcium supplements, dairy, or calcium-fortified products.
Minimum separation. 120
Sources (2)
- Fish DN, Chow AT. The clinical pharmacokinetics of levofloxacin. Clin Pharmacokinet. 1997;32(2):101-19. PMID 9068926
- Wiesner A, Zagrodzki P, Gawalska A, Paśko P. Together or Apart? Revealing the Impact of Dietary Interventions on Bioavailability of Quinolones: A Systematic Review with Meta-analyses. Clin Pharmacokinet. 2024;63(6):773-818. PMID 38807006
Stack Score
How this pair moves the number.
Effect on the composite score
If both Calcium and Levofloxacin 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 documented at /methodology/stack-score.
Check your full routine
One pair was the worked example. NutriStack runs every pair in your stack at once.
Drop in your supplements and prescriptions and the public database surfaces every interaction, synergy, timing rule, and contraindication, every one linked to its primary source.