Practices of Vitamin D Supplementation Leading to Vitamin D Toxicity

Practices of Vitamin D Supplementation Leading to Vitamin D Toxicity: Experience From a Tertiary Care Center of a Low Middle Income Country

To determine the frequency toxicity (>150 ng/ml) in subjects for 25-hydroxyvitamin D (25OHD) and evaluate the vitamin D (VD) supplements used by these subjects.

Study Overview

• Status: Completed
• Conditions: Vitamin D Toxicity
• Intervention / Treatment: Diagnostic test: serum 25OHD testing

Detailed Description

This prospective cross-sectional study was conducted at the Section of Chemical Pathology, Department of Pathology and Laboratory Medicine, AKUH Karachi Pakistan after approval from Aga Khan University Hospital's Ethics Review Committee (ERC ID: 2019-1973-6924). Data of subjects tested for serum 25OHD between April 2020 to March 2021 was reviewed daily and those with 25OHD levels >150 ng/ml were contacted via telephone. Only the initial results of the subjects tested at Clinical Laboratory were included. Those with incomplete clinical history, 25OHD levels <150ng/ml, whose contact numbers were unavailable or not answering telephone calls were excluded. To maintain confidentiality all identifiers were removed, and study identity numbers were generated.

After explaining the reason for phone call, verbal informed consent was taken and clinical information of calcium and VD supplementation including prescribed or self-medicated, indications for prescription, formulation strength, total dosage, frequency, duration, and calcium status was collected on a structured clinical history forms. The hypercalcemia was labeled when serum calcium was >10.2 mg/dl.

Data analysis:

The statistical analysis was performed using the Microsoft Excel 2016. Subjects were categorized into two age groups: <18 years (pediatric) and ≥18 years (adult). Total doses of VD supplements were added to calculate cumulative supplementation and daily supplementation was calculated by dividing cumulative dose by duration of supplementation.

Descriptive statistics median (interquartile range, IQR) were calculated for numerical data while frequency (percentage) for categorical data. Frequencies of subjects with VD toxicity were derived and their correlates were evaluated in the both the age groups. Demographics (age and gender), calcium status of subjects, indications, formulation strengths, frequency, duration, cumulative and daily dose of supplementation were generated.

• Study Type: Observational
• Enrollment (Actual): 186

Contacts and Locations

Study Locations

• Pakistan
  • Sindh
    • Karachi, Sindh, Pakistan, 3500
      • The Aga Khan University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Subjects tested for serum 25OHD

Description

Inclusion Criteria:

• Subjects WITH serum 25OHD levels >150 ng/ml.
• Only the initial results.

Exclusion Criteria:

• Serum 25OHD levels <150ng/ml,
• Incomplete clinical history
• Whose contact numbers were unavailable
• Who were not answering telephone calls

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Pediatric Subjects and adults; Subjects were categorized into two age groups: <18 years (pediatric) and ≥18 years (adult).	Diagnostic test: serum 25OHD testing; Subjects tested for serum 25OHD between April 2020 to March 2021 was reviewed daily and those with 25OHD levels >150 ng/ml were contacted via telephone.
Pediatrics and adults; Subjects were categorized into two age groups: <18 years (pediatric) and ≥18 years (adult).	Diagnostic test: serum 25OHD testing; Subjects tested for serum 25OHD between April 2020 to March 2021 was reviewed daily and those with 25OHD levels >150 ng/ml were contacted via telephone.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Potential vitamin D toxicity	Frequency of potential vitamin D Toxicity and use of VD supplementation including prescribed or self-medicated, indications for prescription, formulation strength, total dosage, frequency and duration will be determined.	April 2020 to March 2021

Collaborators and Investigators

• Sponsor: Aga Khan University Hospital, Pakistan

Study record dates

Study Major Dates

• Study Start (Actual): April 1, 2020
• Primary Completion (Actual): March 31, 2021
• Study Completion (Actual): March 31, 2021

Study Registration Dates

• First Submitted: November 30, 2021
• First Submitted That Met QC Criteria: November 30, 2021
• First Posted (Actual): December 1, 2021

Study Record Updates

• Last Update Posted (Actual): December 16, 2021
• Last Update Submitted That Met QC Criteria: December 14, 2021
• Last Verified: December 1, 2021

More Information

Terms related to this study

• Other Study ID Numbers: 2019-1973-5495

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: To maintain confidentiality all identifiers were removed, and study identity numbers were generated. Individual data will not be shared

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No