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.
300-600mg extract (2.5% ursolic acid)
Morning, With or without food
Standardized extract (leaf)
2000-4000 IU daily
Morning with breakfast
D3 (cholecalciferol) softgel or liquid
2-4 weeks
2-4 weeks
4-8 weeks
4-8 weeks
4-8 weeks
2-4 weeks
4-8 weeks
The Neuroprotective Potential of Ocimum Plant Species: Seasoning the Mind with Sweet and Holy Basil
Nutrients (2025) · Systematic review
This review synthesizes experimental evidence regarding Ocimum species with neuroprotective potential in AD, particularly Ocimum sanctum and Ocimum basilicum.
Modulation of the hypothalamic-pituitary-adrenal (HPA) axis by plants and phytonutrients: a systematic review of human trials
Nutritional neuroscience (2022) · Systematic review
For most phytonutrients, the effects of supplementation on HPA-axis activity in humans is unclear.
Medicinal Plants in the Treatment of Respiratory Diseases and their Future Aspects
Recent patents on biotechnology (2025) · Systematic review
Some medicinal plants, notably Echinacea purpurea and Zingiber officinale, exhibit potential for adjuvant symptomatic therapy in respiratory conditions, such as chronic obstructive pulmonary disease (COPD), bronchitis, asthma, the common cold, cough, and whooping cough.
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.
Effect of Vitamin D Supplementation in Early Life on Children's Growth and Body Composition: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Nutrients (2021) · Meta analysis · n=3960
Vitamin D supplementation during pregnancy was associated with higher triceps skinfold thickness (mm) (MD 0.33, 95% CI, 0.12, 0.54; I2 = 34%) in neonates.
Vitamin D3 has a higher evidence score (9/10 vs 8.5/10) and wins in 2 of 3 categories.
For support mood, Vitamin D3 has a higher relevance score (75 vs 58).
No known interactions between Holy Basil and Vitamin D3 have been documented in our database. However, always consult a healthcare provider before combining supplements.