{"doi":"10.1210/clinem/dgab432","title":"Mild Idiopathic Infantile Hypercalcemia—Part 2: A Longitudinal Observational Study","abstract":"CONTEXT: Idiopathic infantile hypercalcemia (IIH) is an uncommon disorder with variable clinical features. The natural history and response to dietary calcium and vitamin D restriction in IIH remains unclear. OBJECTIVE: The aim of this study is to describe the clinical and biochemical response to dietary calcium and vitamin D restriction in a genetically characterized cohort of mild IIH. METHODS: This is a longitudinal, observational cohort study of 20 children with mild IIH monitored for a median of 21months. Biochemical measures, dietary assessment, and yearly renal ultrasound results, since the time of diagnosis, were obtained and assessed prospectively every 4 to 6 months. RESULTS: Median age at initial diagnosis was 4.5 months. Median levels of serum calcium (2.82 mmol/L) and 1,25 (OH)2D (192 pmol/L) were elevated, whereas serum PTH was reduced (10 ng/L). Urinary calcium:creatinine ratio was elevated for some, but not all individuals (median 1.49 mmol/mmol). All patients who were managed with a low-calcium diet showed an improvement in serum and urinary calcium measures, but the serum concentration of 1,25 dihydroxyvitamin D (1,25(OH)2D) and 1,25(OH)2D/PTH ratio remained elevated. In 2 of the 11 subjects, renal calcification worsened. There were no differences in response between individuals with CYP24A1 or SLC34A1/A3 variants. CONCLUSION: The clinical presentation of mild IIH is variable, and dietary calcium and vitamin D restriction does not consistently normalize elevated 1,25(OH)2D concentrations or prevent worsening of renal calcification in all cases. Therapeutic options should target the defect in vitamin D metabolism.","journal":"The Journal of Clinical Endocrinology & Metabolism","year":2021,"id":192984,"datarank":0.4616292639784162,"base_score":2.4849066497880004,"endowment":2.4849066497880004,"self_citation_contribution":0.37273599746820013,"citation_network_contribution":0.08889326651021608,"self_endowment_contribution":0.37273599746820013,"citer_contribution":0.08889326651021608,"corpus_percentile":58.93091978030479,"corpus_rank":5310,"citation_count":11,"citer_count":8,"citers_with_citation_signal":3,"citers_with_endowment":3,"datacite_reuse_total":0,"is_dataset":true,"is_dataset_confidence":0.5491,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":722420,"name":"Michelle Furman","orcid":null,"position":1,"is_corresponding":false},{"id":721688,"name":"Esther Assor","orcid":"0000-0003-4278-8580","position":2,"is_corresponding":false},{"id":722421,"name":"Yesmino Elia","orcid":null,"position":3,"is_corresponding":false},{"id":721691,"name":"Carol Collins","orcid":"0000-0003-0191-2549","position":4,"is_corresponding":false},{"id":331595,"name":"Kenneth E. Thummel","orcid":"0000-0002-7799-3739","position":5,"is_corresponding":false},{"id":289381,"name":"Michael A. Levine","orcid":"0000-0003-0036-7809","position":6,"is_corresponding":false},{"id":721692,"name":"Etienne Sochett","orcid":"0000-0002-7027-7123","position":7,"is_corresponding":false},{"id":721686,"name":"Nina Lenherr‐Taube","orcid":"0000-0001-8918-3963","position":0,"is_corresponding":true}],"reference_count":34,"raw_metadata":null,"created_at":"2026-07-18T23:49:47.463744Z","pmid":"34139759","pmcid":"PMC8475233","fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}