Can you take Vitamin A and Vitamin D3 together?
At normal doses, they're fine together. Above 10,000 IU retinol, Vitamin A can interfere with Vitamin D's effects on calcium metabolism.
Severity
Caution
Evidence
moderate
Timing
Together at normal doses.
How it works
Retinol and calcitriol compete for RXR nuclear receptor binding sites, with competition becoming meaningful at high retinol concentrations.
The antagonism is primarily a concern above 10,000 IU/day retinol combined with marginal Vitamin D status. Beta-carotene does not share this interaction. Standard multivitamin levels of both are safe together.
What to do
Keep retinol moderate if you take D3. Prefer beta-carotene where possible. Standard supplement doses (5,000 IU A with 1,000–5,000 IU D3) are well within the safe range.
Frequently asked
Should I separate Vitamin A and Vitamin D3?
Consider separating them. Together at normal doses. Consult a healthcare professional for personalised advice.
Why do Vitamin A and Vitamin D3 interact?
Retinol and calcitriol compete for RXR nuclear receptor binding sites, with competition becoming meaningful at high retinol concentrations.
How strong is the evidence for this interaction?
The evidence is moderate. Some studies support this interaction, but more research may be needed.
About these supplements
Other Vitamin D3 interactions
Related reading
Check your full stack
for interactions.
See what competes, what combines well, and when to take everything. Every interaction cites a published source.
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6 supplements
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1 flagZinc and Iron compete for the same absorption pathway. Take at least 2 hours apart.
Supplements
This information is for educational purposes only. It is not medical advice and does not diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional.