Cianferotti · Reviews in endocrine & metabolic disorders 2026 · narrative review · n=?

Too much vitamin D? a drug safety review.

Cited 4 times in the scientific literature.

Level 5 - mechanism / opinion, no new human data

Narrative review without systematic search or meta-analysis

PubMed 41483069 · doi:10.1007/s11154-025-10011-8 · record verified 2026-08-26

What was done

This narrative drug safety review examined safety profiles, correct intake recommendations, and patterns of overuse regarding vitamin D pro-hormone supplementation from nutritional sources and supplements. It evaluated common clinical scenarios involving potential improper use beyond bone homeostasis, standard dosing intervals, and requirements for laboratory monitoring.

What was found

The abstract reports no numerical data, specific dosage thresholds, or sample sizes. Qualitatively, it reports that supplementation with vitamin D pro-hormones is effective and safe at standard daily, weekly, or monthly doses. Routine 25-hydroxyvitamin D monitoring is generally unnecessary once target serum levels are achieved, though reassessment is appropriate when clinical conditions change. Long-term use of calcidiol requires monitoring, and excessive ingestion via overprescribing or overdosing is potentially harmful.

Why it matters

It highlights growing concerns over widespread vitamin D oversupplementation for non-skeletal conditions and clarifies monitoring needs for specific forms like calcidiol.

Limits

The abstract describes a narrative review without systematic search criteria, meta-analytic pooling, or quantitative safety thresholds. No empirical patient data, adverse event frequencies, or specific numerical definitions of safe versus toxic dosing are provided.

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