Vitamin D3, Folic Acid and Fexofenadine in Healthy Volunteers

Study Overview
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Brief Summary
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The study is conducted to assess the effect of a vitamin D3 supplementation on the activities of two intestinal transporters and on the pharmacokinetics of the transporter substrates folic acid and fexofenadine. Trial with medicinal product

Official Title
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Effects of Vitamin D3 (1,25 Dihydroxyvitamin D3) on Pharmacokinetics and Absorption of Folic Acid and Fexofenadine in Healthy Volunteers

Conditions
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Physiological Effects of Vitamin D

Intervention / Treatment
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* Drug: Vitamin D


Participation Criteria
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Eligibility Criteria
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Inclusion criteria: male or female age 18 to 65 years at study entry signed informed consent form Body Mass Index > 18 - < 30 kg/m2 Participants must not have any other diseases (as assessed by the screening examination) Participants must not take any concomitant medications except oral contraceptives in females Normal blood count Exclusion criteria: Subjects with confirmed or suspected hypersensitivity towards the study medications Contemporaneous participation in any other study Females only: pregnancy Females only: breast-feeding Clinically significant abnormal laboratory findings Known or suspected present or past malignancies of any kind Known or suspected active infections, serious infections in the preceding 3 months Positive hepatitis B, hepatitis C and / or HIV 1/2 serology Subjects known or suspected not to comply with the study regulations Subjects employed at the participating departments of the University Hospital Zürich. Known or suspected present or past diseases which may interfere with the study smokers alcohol or drug abuse

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 1, 25 dihydroxyvitamin D3 intake<br>This is a single arm study. | Drug: Vitamin D<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ratio of the area under the concentration vs. time curve (AUC) of fexofenadine after vitamin D over AUC of fexofenadine before vitamin D | Changes in single-dose pharmacokinetics of racemic fexofenadine at the end of a substitution with 1,25 dihydroxyvitamin D3 in comparison to pharmacokinetics before the substitution. | 10 days | 
| Ratio of Area under the concentration vs. time curve (AUC) of folic acid after vitamin D over AUC of folic acid before vitamin D | Changes in single-dose pharmacokinetics of folic acid at the end of a substitution with 1,25 dihydroxyvitamin D3 in comparison to pharmacokinetics before the substitution. | 10 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number and characteristics of participants with adverse events |  | 10 days | 
| transporter mRNA quantity | Comparison of transporter mRNA levels after ten days of vitamin D3 intake in comparison to the levels before intake. | 10 days |