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
Head-to-head evidence comparison — which supplement is right for you?
Inulin and Vitamin D3 are closely matched across evidence, studies, and safety.
Verdict
Likely helps
9 of 10 studies with measurable effects showed benefit.
Top outcomes
Verdict
Probably helps
15 of 26 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Inulin and Vitamin D3 have evidence — compare verdict strength side-by-side.
5-15g daily
With meals or in beverages, Can be taken any time of day, Divide into multiple doses if taking higher amounts
Chicory root inulin powder
2000-4000 IU daily
Morning with breakfast
D3 (cholecalciferol) softgel or liquid
2-4 weeks
1-2 weeks
2-4 weeks
First 1-2 weeks
4-8 weeks
4-8 weeks
2-4 weeks
4-8 weeks
The effects of inulin-type fructans on cardiovascular disease risk factors: systematic review and meta-analysis of randomized controlled trials
The American journal of clinical nutrition (2024) · Meta analysis · n=2518
ITF may reduce low-density lipoprotein, triglycerides, and body weight.
The effects of chicory inulin-type fructans supplementation on weight management outcomes: systematic review, meta-analysis, and meta-regression of randomized controlled trials
The American journal of clinical nutrition (2024) · Meta analysis · n=1184
Chicory ITF significantly reduced body weight [mean difference (MD): -0.97 kg; 95% CI: -1.34, -0.59); n = 1184] compared with placebo.
Galactomannans are the most effective soluble dietary fibers in type 2 diabetes: a systematic review and network meta-analysis
The American journal of clinical nutrition (2023) · Meta analysis · n=2685
Galactomannans had the highest effect on reducing the levels of HbA1c (SUCRA: 92.33%) and fasting blood glucose (SUCRA: 85.92%).
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) · Meta analysis · n=5205
Mean body mass index (BMI) was 27.5 kg/m2 (SD = 5.3), with 51% female and 17% Black race/ethnicity.
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
12% reduction in respiratory infections overall
Meta-analysis showed modest weight loss of -0.97 kg but with considerable heterogeneity (I2: 73%). Combined fiber study showed larger effect but included other fibers alongside inulin.
Meta-analysis showed 12% overall reduction in respiratory infections, with greater benefits in severely deficient individuals. Daily dosing more effective than bolus. Conservative estimate assumes most users not severely deficient.
AI-estimated from published studies. Interpret as directional guidance.
Both Inulin and Vitamin D3 are closely matched — the best choice depends on your specific health goals.
For support immune system, Vitamin D3 has a higher relevance score (92 vs 52).
No known interactions between Inulin and Vitamin D3 have been documented in our database. However, always consult a healthcare provider before combining supplements.