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Head-to-head evidence comparison — which supplement is right for you?
Shiitake vs Vitamin D3: Vitamin D3 has the stronger overall evidence (7.5 vs 4.5/10); they're alternatives for support immune system — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Vitamin D3 wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Too few graded studies
1 of 1 studies with measurable effects showed benefit.
Top outcomes
Verdict
Probably helps
7 of 14 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Shiitake and Vitamin D3 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)
2000-4000 IU daily
Morning with breakfast
D3 (cholecalciferol) softgel or liquid
and 1 more not shown
4 weeks
8-12 weeks
4-8 weeks
4-8 weeks
4-8 weeks
2-4 weeks
4-8 weeks
Critical Review on the Anti-Tumor Activity of Bioactive Compounds from Edible and Medicinal Mushrooms over the Last Five Years
Nutrients (2025) · 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
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) · 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 D supplementation vs. placebo and incident type 2 diabetes in an ancillary study of the randomized Vitamin D and Omega-3 Trial
Nature communications (2025) · Rct · n=22220
Ancillary analysis of VITAL: 22,220 adults without T2D randomized to vitamin D3 2000 IU/day or placebo, with a meta-analysis of 3 additional trials.
Vitamin D Supplementation for Patients with Dysmenorrhoea: A Meta-Analysis with Trial Sequential Analysis of Randomised Controlled Trials
Nutrients (2024) · Meta analysis · n=687
TSA revealed that the current RCTs provide sufficient information.
Vitamin D and respiratory tract infections
BMJ (2017) · Meta analysis · n=11321
25 RCTs, 11 321 participants aged 0 to 95 years. Vitamin D reduced acute respiratory tract infection overall (adjusted OR 0.88, 95% CI 0.81 to 0.96).
Both points come from a meta-analysis of double-blind cholecalciferol trials in people aged 60 and over (PMID 15886381). Trials at 700 to 800 IU a day cut hip fracture risk by 26% (RR 0.74) and non-vertebral fractures by 23%, plotted at 800 IU. Trials at 400 IU a day showed no benefit (hip fracture RR 1.15), and the WHI trial of 400 IU with 1,000 mg calcium did not significantly reduce hip fracture (PMID 16481635). Most of these trials also gave calcium, and the Cochrane review found vitamin D alone unlikely to prevent fractures while vitamin D with calcium gave a small reduction (PMID 24729336). Doses above 800 IU were not compared, so no optimal dose or ceiling is set.
AI-estimated from published studies. Interpret as directional guidance.
Vitamin D3 has a higher evidence score (7.5/10 vs 4.5/10) and wins in 2 of 3 categories.
For support immune system, Vitamin D3 has a higher relevance score (92 vs 75).
No documented interaction was found in the data searched. This does not establish that this exact combination is safe.
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The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.