Modified-Release Calcifediol Capsule.
Research-backed compound with potential health benefits. 25-hydroxyvitamin D in extended-release form. Brand name Rayaldee.
Reviewed March 2026
- Category
- Compound
What Modified-Release Calcifediol Capsule is, and what it does.
- Does it work
- Medical treatment, not a supplement. If you have kidney issues, ask your nephrologist.
- How much to take
- Start with 15mcg to 30mcg a day, which is the daily maintenance band. The 60mcg used in trials is a research condition rather than a daily target.
- Time to feel it
- There's no day-to-day sensation. The change shows up on a blood panel, with 25-hydroxyvitamin D climbing steadily across roughly six to twelve weeks of daily use.
- The first dose
- Day one is quiet. The extended-release shell lets calcifediol out slowly along the gut instead of in one spike, and nothing registers as a feeling.
- With regular use
- Weeks of daily use raise and then hold circulating 25-hydroxyvitamin D, the marker vitamin D status is read from on a lab report.
- How well tolerated
- This is a prescription medicine rather than a supplement. A clinician prescribes it and monitors blood calcium and vitamin D, so follow that plan rather than self-dosing.
- How it feels
- Nothing you can point to. It's a slow-release capsule swallowed once a day, and its work is read off a lab report rather than felt.
- The overlooked benefit
- Calcifediol is already 25-hydroxylated, so it skips the liver step vitamin D3 has to pass through, and the slow-release shell avoids the peak a single large dose gives.
15 to 30mcg a day is where Modified-Release Calcifediol Capsule works.
Source: Sprague et al., Am J Nephrol, 2014; Rayaldee prescribing information
The proof, claim by claim.
These words describe the research, not the molecule's worth. Research strength is how much work stands behind one claim, and it is never a product score.
Modified-Release Calcifediol Capsule is documented in the library; the clinical read is in the queue. Nothing about the strength of the research prints until the read is done.
- Raising serum 25-hydroxyvitamin DRandomised trial
- Parathyroid hormone concentrationsRandomised trial
- Gradual release compared with a bolus doseRandomised trial
Questions people ask about Modified-Release Calcifediol Capsule.
- When should I take it?
- Timing matters less than consistency. Pick a time that works for you and take it daily.
- Can I take it with other supplements?
- Usually fine. The main thing to watch is not doubling up on the same ingredient from different products. If you're on prescription meds, check with your pharmacist first.
- Any side effects to watch for?
- Most people tolerate it well at recommended doses. GI upset is the most common complaint with any supplement. Start with a lower dose and work up. If something feels off, stop and reassess.
No pairing data for Modified-Release Calcifediol Capsule yet.
Nothing on file for Modified-Release Calcifediol Capsule, either from a combination trial or from settled biochemistry. When either lands, it appears here with its source.
Stitching two separate single-ingredient studies into a pairing is the one thing this engine will not do. When a study of the combination itself holds up at source, it lands here with its citation.
No invented synergy. Where actives were studied on their own rather than together, the record shows each on its own evidence, never a combined effect no trial measured.
Research strength. Research strength says how much work stands behind the combination. It is never a product score.
Independent record. Every finding is cited to a named trial, dated, and never written by the brand.
21 pairings are live across the library today. Checked 9 August 2026.
Nothing specific on file for Modified-Release Calcifediol Capsule. Match the label to the daily amount above, and tell your doctor what you take.
Not medical advice. Show the label to your pharmacist.Getting Modified-Release Calcifediol Capsule from food.
The whole-food sources on file. A supplement closes the gap, it does not replace dinner.
A gram-for-gram figure (how much of each you would eat to match a dose) will appear here once it is sourced and reviewed. This page will not print a number it cannot cite.
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. This information is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.