NSTK · 01.2026Independent supplement reference

Edition 1.0Updated August 1, 2026

Supplement × Supplement·Evidence index

Vitamin A and Vitamin D3: what the published research says

PubMed indexes 2 records that name Vitamin A and Vitamin D3 together, either in the title or in an interaction, co-administration, or pharmacokinetic context. Each one is listed below with its study design and, where the abstract states one, the authors’ own conclusion, quoted and linked. This page reports that literature. It does not tell you whether to combine them.

Studies listed

Human studies

Reviews & meta-analyses

Published

2023–2025

Read the studies ↓ How we select sources

Read this first

An evidence index, not guidance.

Every statement below is attributed to a named, dated, linked source.

This page lists published research relevant to Vitamin A and Vitamin D3. It deliberately does not state whether the combination is safe, whether it interacts, in which direction, at what dose, or how far apart to take them.

A study appearing here is not proof that an interaction exists. Two substances can be named together in a paper that never tested them in combination, and a source listed as background may cover only one of them.
Findings are quoted from each abstract as the authors wrote them. NutriStack has not re-analysed, pooled, or reconciled them, and they may disagree with each other.
NutriStack’s own interaction assessment for this pair is not published here. It has not completed qualified-human clinical review, so it is withheld from search. See the publication gate.
Nothing here is medical advice. Decisions about prescription medication and supplements belong with your prescriber or pharmacist, who can see your full regimen.

The research

2 studies naming Vitamin A and Vitamin D3.

Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.

Retinol and cholecalciferol affect buserelin-induced estrous in anestrous mares.

Tropical animal health and production · 2025 · PMID 40095200

Animal study

“Supplementing with retinol and cholecalciferol improved the rate of buserelin-induced estrous in anestrous mares. Further research is necessary to determine underlying mechanisms.”
Bukhari et al. · From the abstract

Names both Vitamin A and Vitamin D3 in its title.

Vitamin A and vitamin D3 protect the visual apparatus during the development of dopamine-2 receptor knockout mouse model of Parkinsonism.

Journal of complementary & integrative medicine · 2023 · PMID 37311120

Animal study

“Dopamine-deficient models of movement disorders are associated with loss of visual functions, especially due to thinning of the retina, retinal fold, retinal detachment, and neurodegeneration in the visual cortex. Supplementation during the development of the model with vitamin D3 and vitamin A prevented the deterioration of the retina and visual cortex by reducing the degree of oxidative stress and cytotoxicity.”
Umar et al. · Authors' conclusion

Names both Vitamin A and Vitamin D3 in its title.

Limitations

What this evidence cannot tell you.

Search-based evidence indexes have real limits, and it is worth being explicit about them:

Selection. These records were found by searching PubMed titles and abstracts for both substance names alongside interaction and pharmacokinetic terms. Relevant work that phrases things differently, or is not indexed in PubMed, will be missing.
No effect size. The quoted conclusions are the authors’ words about their own study. We have not extracted effect direction or magnitude, and a single study’s conclusion is not a consensus.
Population mismatch. Findings in healthy volunteers, animals, or a specific patient group may not transfer to you, your dose, or your formulation.
Absence is not safety. Few published studies means the combination is under-studied, which is not the same as established as safe.

NutriStack

Track what you actually take.

NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers Vitamin A, Vitamin D3, and several hundred other substances.

The checker is a research and organisation tool, not a clinical decision aid, and its per-pair assessments are excluded from search until they pass claim-level review.

Get NutriStack free → Read the methodology

NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.