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Head-to-head evidence comparison — which supplement is right for you?
Vitamin D3 wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Probably helps
18 of 30 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
12 of 13 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both Vitamin D3 and Vitex have evidence — compare verdict strength side-by-side.
2000-4000 IU daily
Morning with breakfast
D3 (cholecalciferol) softgel or liquid
20-40mg extract (standardized to 0.5% agnuside)
Morning, Consistently at same time daily
Standardized extract (0.5% agnuside or 0.6% aucubin)
4-8 weeks
4-8 weeks
2-4 weeks
4-8 weeks
1-3 cycles
2-3 cycles
1-2 cycles
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
Vitex agnus-castus in premenstrual syndrome: A meta-analysis of double-blind randomised controlled trials
Complementary Therapies in Medicine (2019) · Meta analysis · n=1878
Vitex significantly reduced overall PMS symptom scores vs placebo
Herbal medicine for depression and anxiety: A systematic review with assessment of potential psycho-oncologic relevance
Phytotherapy research : PTR (2018) · Systematic review
Overall, 45% of studies reported positive findings with fewer adverse effects compared with conventional medications.
A Critical Approach to Evaluating Clinical Efficacy, Adverse Events and Drug Interactions of Herbal Remedies
Phytotherapy research : PTR (2016) · Review
A critical evaluation of the clinical data regarding the adverse effects has shown that herbal remedies are generally better tolerated than synthetic medications.
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.
Based on meta-analysis of RCTs showing large effect size. Most effective for irritability, mood swings, and breast tenderness. Standardized extracts (Ze 440, BNO 1095) had strongest evidence. High heterogeneity noted between studies.
AI-estimated from published studies. Interpret as directional guidance.
Vitamin D3 has a higher evidence score (7.5/10 vs 7/10) and wins in 2 of 3 categories.
For testosterone & cortisol balance, Vitex has a higher relevance score (92 vs 55).
No known interactions between Vitamin D3 and Vitex have been documented in our database. However, always consult a healthcare provider before combining supplements.