Vitamin D3: Identification of central nervous system targets using high-technology functional MRI (D-LIGHTFUL)

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 60

Inclusion Criteria

- Age between 18 - 35 years
- Ability to provide informed consent
- Right-handedness
- Stable weight (<5% change) for 3 months prior to study assessment,
Additionally, for the obese subset:
- BMI between 30 - 40 kg/m2
- Metabolically unhealthy, defined as fasting plasma insulin levels >74 pmol/l
at screening

Exclusion Criteria

- Any medical or psychiatrical disorder (except stable obesity-related glucose
intolerance, hypertension, dyslipidemia and/or controlled hypothyroidism)
- Subjects taking any of the following medications: anticonvulsants,
corticosteroids, digitalis, magnesium-containing preparations (e.g. antacids),
thiazide-diuretics, phosphodiesterase inhibitors, serotonergic medications
(e.g. SSRI, SNRI, MAO inhibitors, buproprion, tricyclic antidepressants, St.
John*s Wort), codeine (CYP2D6 inhibition), tamoxifen, timolol, warfarin,
exogenous insulin, GLP-1 agonists, DPP4 inhibitors, SGLT2 inhibitors,
beta-blockers, homeopathic supplements
- The use of weight loss agents (e.g. orlistat, phentermine, topiramate,
fenfluramin, dexfenfluramine, amphetamines, GLP-1 agonists) or use within 3
months prior to study
- Weight loss surgery or gastrectomy
- Childhood-onset obesity
- Breakfast skippers
- Shift workers
- Contraindication to MRI scanning (e.g. claustrophobia, pacemaker, metal IUD)
- Significant sensory or motor impairment
- Subjects who cannot adhere to the experimental protocol for any reason

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>The effect of calcitriol on brain activity in the hypothalamus and reward areas<br /><br>as well as functional connectivity as measured by fMRI during food stimuli. </p><br>

Secondary Outcome Measures

Name	Time	Method
<p>The effect of calcitriol on:<br /><br>- Subjective (VAS) scores of hunger and satiety<br /><br>- Neuropsychological functioning and feeding behavior characteristics as<br /><br>assessed by questionnaires<br /><br>- Objective scores of hunger and satiety as measured during an ad-libitum<br /><br>buffet meal<br /><br>- The gut microbiota and its association with changes in fMRI responses<br /><br>- Circulating levels of glucose, insulin, and hormones</p><br>