Side by side

Compare supplements

Put up to three ingredients next to each other. See where the evidence, dosing, timing, and tradeoffs differ.

Supplement 1Supplement 2Supplement 3

Measure

Add a supplement

Evidence

Strong evidence

Common protocol600–800 IU/day total intake——

Protocols mapped

2 goal-specific

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Timing

With a meal containing fat

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Expected effect

8–12 weeks for blood-level changes

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Primary uses

Deficiency correctionBone healthVitamin D status

Watch for

Excess intake can cause hypercalcemia

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