Vitamin D Toxicity-A Clinical Perspective.
Level 5 - mechanism / opinion, no new human data
Narrative review without systematic methodology
PubMed 30294301 · doi:10.3389/fendo.2018.00550
What was done
This narrative review synthesized clinical knowledge on vitamin D toxicity, covering clinical symptoms, diagnostic thresholds, exogenous causes (iatrogenic overdosing), endogenous causes (granulomatous disorders, lymphomas, idiopathic infantile hypercalcemia, Williams-Beuren syndrome), and underlying biochemical mechanisms.
What was found
The review identifies serum 25-hydroxyvitamin D concentrations exceeding 150 ng/ml (375 nmol/l) as the characteristic threshold for toxicity due to overdosing. Key clinical symptoms reported include confusion, apathy, recurrent vomiting, abdominal pain, polyuria, polydipsia, and dehydration secondary to severe hypercalcemia. No primary empirical trial data or quantitative effect sizes are provided in the abstract.
Why it matters
As public self-supplementation with vitamin D increases, clinicians must recognize the signs of toxicity and understand that both excessive intake and underlying metabolic or genetic disorders can cause severe hypercalcemia.
Limits
This is a narrative review with no primary data, quantitative meta-analysis, or systematic search methodology reported in the abstract. Quantitative incidence rates, exact toxic dose ranges, and clinical outcome statistics are not provided.
Cited by
- supports Published case reports show that vitamin D toxicity requiring hospitalization occurs at blood levels of 200 to 250 ng/mL and above.