Loading…
We use essential cookies (authentication, your saved goals/stack) by default. With your permission we'll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more about cookies
Head-to-head evidence comparison — which supplement is right for you?
Shiitake and Vitamin C are closely matched across evidence, studies, and safety.
Verdict
Probably helps
3 of 5 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
12 of 17 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Shiitake and Vitamin C have evidence — compare verdict strength side-by-side.
5-15g dried mushroom or 1-3g extract daily
With meals, Divided doses if using higher amounts
Shiitake extract (standardized to polysaccharides)
500-1000mg
With meals, Split doses if taking >500mg
Ascorbic acid or buffered vitamin C
4 weeks
8-12 weeks
4-8 weeks
Ongoing
1-2 weeks
4-8 weeks
With high doses (>2g)
Critical Review on the Anti-Tumor Activity of Bioactive Compounds from Edible and Medicinal Mushrooms over the Last Five Years
Nutrients (2025) · Systematic review
In recent years, the incidence rate of cancer has been on the rise all over the world, and the age of cancer patients has shown a younger trend, which seriously endangers patients' health.
Vitamin B12 sources in non-animal foods: a systematic review
Critical reviews in food science and nutrition (2023) · Systematic review · n=25
In the last decade, more sensitive method for real B12 determination was used, the liquid chromatography-electrospray ionization tandem mass spectrometry chromatograms.
Anti-Cancer Potential of Edible/Medicinal Mushrooms in Breast Cancer
International journal of molecular sciences (2023) · Systematic review
In this article, we reviewed mushrooms showing antineoplastic activity again breast cancer cells, especially focusing on the possible bioactive compounds involved and their mechanisms of action.
Vitamin C supplementation for prevention and treatment of pneumonia
The Cochrane database of systematic reviews (2020) · Meta analysis · n=2774
We are uncertain of the effect of vitamin C supplementation on mortality due to pneumonia (RR 0.21, 95% CI 0.03 to 1.66; 1 study, 57 participants; very low-quality evidence).
Vitamin C supplementation in pregnancy
The Cochrane database of systematic reviews (2015) · Meta analysis · n=20038
Conversely, the risk of term PROM was increased when supplementation included vitamin C and vitamin E (average RR 1.73, 95% CI 1.34 to 2.23; 3060 participants; two studies; I² = 0%).
Enhanced Vitamin C Delivery: A Systematic Literature Review Assessing the Efficacy and Safety of Alternative Supplement Forms in Healthy Adults
Nutrients (2025) · Systematic review
Most studies (77%) had a low risk of bias.
Based on beta-glucan studies and one pilot RCT (n=239) showing modest immune response trends. Evidence limited by small sample sizes and primarily preclinical data. Effects may vary significantly by extract standardization and processing method.
Based on 3 meta-analyses of sepsis patients. One study showed RR 0.60 for mortality reduction, but another showed increased risk (RR 1.21). Evidence quality rated as low to very low. Effect limited to intravenous administration in critically ill patients.
AI-estimated from published studies. Interpret as directional guidance.
Both Shiitake and Vitamin C are closely matched — the best choice depends on your specific health goals.
For support immune system, Vitamin C has a higher relevance score (85 vs 75).
No known interactions between Shiitake and Vitamin C have been documented in our database. However, always consult a healthcare provider before combining supplements.