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Supplement × Prescription·Evidence index

Sulfasalazine and Vitamin B9: what the research found

PubMed indexes 8 records that name Sulfasalazine and Vitamin B9 together, either in the title or in an interaction, co-administration, or pharmacokinetic context. The key findings come first, in the authors’ own words, followed by every study with its design and PubMed link.

A summary of published research, not medical advice. A pharmacist can check any combination against your full list of medicines and supplements.

Key findings

What the studies concluded.

Reviews and human studies first. Each quote is the authors’ own conclusion about their study, not a NutriStack assessment, and a single study is not a consensus.

“Both sulfasalazine therapy and folate supplementation have a protective effect in colorectal cancer development in a population of patients with longstanding ulcerative colitis. Randomized controlled trials are needed to explore these hypotheses.”

Diculescu et al. · 2003 · Review or meta-analysis · details

“Isothermal stress testing, forced degradation and dissolution studies, followed by the analysis with a developed chromatographic method for the monitoring of folic acid, sulfasalazine and two of its related impurities, sulfapyridine and salicylic acid, gave us an insight into its chemical compatibility.”

Jeličić et al. · 2021 · Study · details

“These results are interpreted to indicate that sulfasalazine interferes with a folate recognition site which is common to these enzymes and to the intestinal transport system. Sulfasalazine, therefore, has certain properties of an antifolate drug.”

The research

8 studies naming Sulfasalazine and Vitamin B9.

Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.

Folic acid and sulfasalazine for colorectal carcinoma chemoprevention in patients with ulcerative colitis: the old and new evidence.

Romanian journal of gastroenterology · 2003 · PMID 14726972

Meta-AnalysisHuman subjects

“Both sulfasalazine therapy and folate supplementation have a protective effect in colorectal cancer development in a population of patients with longstanding ulcerative colitis. Randomized controlled trials are needed to explore these hypotheses.”

Diculescu et al. · Authors' conclusion

Names both Sulfasalazine and Vitamin B9 in its title.

Drug-Drug Compatibility Evaluation of Sulfasalazine and Folic Acid for Fixed-Dose Combination Development Using Various Analytical Tools.

Pharmaceutics · 2021 · PMID 33802955

“Isothermal stress testing, forced degradation and dissolution studies, followed by the analysis with a developed chromatographic method for the monitoring of folic acid, sulfasalazine and two of its related impurities, sulfapyridine and salicylic acid, gave us an insight into its chemical compatibility.”

Jeličić et al. · From the abstract

Names both Sulfasalazine and Vitamin B9 in its title.

Inhibition of folate enzymes by sulfasalazine.

The Journal of clinical investigation · 1978 · PMID 22555

“These results are interpreted to indicate that sulfasalazine interferes with a folate recognition site which is common to these enzymes and to the intestinal transport system. Sulfasalazine, therefore, has certain properties of an antifolate drug.”

Selhub et al. · From the abstract

Names both Sulfasalazine and Vitamin B9 in its title.

Limitations

What this evidence cannot tell you.

Search-based evidence indexes have real limits, and it is worth being explicit about them:

How to read this page

A literature summary, not guidance.

NutriStack

Track what you actually take.

NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers Sulfasalazine, Vitamin B9, and several hundred other substances.

Log your routine, get reminders at the times you choose, and scan a label to add a product. The checker is a research and organisation tool, not a clinical decision aid.

NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.