What kind of interaction is it?

Synergy: a documented combination effect that is stronger or more useful than either substance taken alone.

Is this interaction backed by published research?

Yes. NutriStack lists 2 citation rows for the Alendronate + Vitamin D3 pair, each linking to PubMed by PMID where available. Full sourcing methodology at https://nutristackapp.com/methodology/interactions.

Interaction databaseSupplement × PrescriptionReviewed May 2026

Alendronate and Vitamin D3, a synergy.

Q: Can I take Alendronate and Vitamin D3 together?

Yes. The combination of Alendronate and Vitamin D3 produces a measurable benefit. Adequate vitamin D status is essential for alendronate to work properly. In a multi-year cohort, women whose 25(OH)D rose the most during and after alendronate had nearly double the lumbar-spine BMD gain compared to those whose vitamin D barely moved, and 25(OH)D change independently predicted BMD response. Vitamin D deficiency is also a key driver of post-dose hypocalcemia.

Q: How does this affect a NutriStack Stack Score?

+2 to your Stack Score per scored synergy row.

Adequate vitamin D status is essential for alendronate to work properly. In a multi-year cohort, women whose 25(OH)D rose the most during and after alendronate had nearly double the lumbar-spine BMD gain compared to those whose vitamin D barely moved, and 25(OH)D change independently predicted BMD response. Vitamin D deficiency is also a key driver of post-dose hypocalcemia.

2 primary source citations. Strong evidence. Last verified May 30, 2026.

Open the interaction checker →Read the methodology

One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.

Sourcing standards·Evidence tiers

From the interaction database

What the row says.

Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.

At a glance

Substances: Alendronate and Vitamin D3
Pair type: Synergy
Evidence (highest tier): Strong
Source citations: 2 sources
Stack Score effect: +2 to your Stack Score (per scored synergy row).
Scope: Supplement × Prescription
Last verified: May 30, 2026

Synergy · Strong evidence

Synergy

What is happening. Adequate vitamin D status is essential for alendronate to work properly. In a multi-year cohort, women whose 25(OH)D rose the most during and after alendronate had nearly double the lumbar-spine BMD gain compared to those whose vitamin D barely moved, and 25(OH)D change independently predicted BMD response. Vitamin D deficiency is also a key driver of post-dose hypocalcemia.

Mechanism. Vitamin D drives intestinal calcium absorption and suppresses secondary hyperparathyroidism. Without it, bisphosphonate-induced inhibition of bone resorption can precipitate hypocalcemia and blunt BMD gains, because remodeling cannot proceed normally.

Recommendation. Maintain vitamin D3 800-2000 IU daily (or as directed) while on alendronate, and aim for serum 25(OH)D above 30 ng/mL. Vitamin D can be taken with food at any time of day; it does not need to be separated from the alendronate dose.

Sources (2)

Stack Score

How this pair moves the number.

Effect on the composite score

If both Alendronate and Vitamin D3 are in the same stack, this pair applies +2 to your Stack Score (per scored synergy row).

The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.

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