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Taking people in BelgiumPhase 2

Tests vitamin D supplements for low free testosterone in men with type 2 diabetes

Tests vitamin D supplements in adult men with type 2 diabetes and low testosterone.

Key facts

Who runs it
UZ Brussel
Where
Jette, BelgiumSee the site
Registry title
Vitamin D Supplementation to increase free testosteron in Type 2 Diabetes Mellitus men: a Placebo-controlled Randomized Clinical Trial
Status
Recruiting
Phase
Phase 2
People taking part
100 people, planned
Started
5 Dec 2018
Expected to end
31 Dec 2030
Type of study
Interventional
Record updated
27 October 2026

Who can take part

AI summary

From the trial's eligibility criteria. Machine-read from the registry text on this page, so it can be wrong. The registry text below and the trial team decide who can take part.

The trial is looking for men with type 2 diabetes who have low testosterone and low vitamin D. It tests vitamin D to raise free testosterone.

Age
18 - 65 years
Sex
Men only
Disease stage
Type 2 diabetes with HbA1c of 64 mmol/mol (8%) or lower and BMI under 40 kg/m²
Earlier treatment
No testosterone supplements. No vitamin D supplements within 2 months before the screening visit and during the study.
Biomarker or test result
Vitamin D under 75 nmol/L and total testosterone under 11 nmol/L

Main reasons for not taking part

  • Use of testosterone supplements
  • Vitamin D supplements within 2 months before screening
  • Known bone disease such as osteoporosis, Paget disease or primary hyperparathyroidism
  • Chronic kidney failure (eGFR under 60 mL/min/1.73 m2 for 3 months or more)
  • Chronic liver failure or past removal of a testicle (orchidectomy)

The registry criteria, word for word

Show all 20 criteriaShow less

Who can take part

  • Vitamin D < 75 nmol/L
  • Caucasian men
  • Age: 18 - 65 years
  • BMI < 40 kg/m²
  • Type 2 diabetes mellitus
  • HbA1c ≤ 64 mmol/mol, ( 8%)
  • Total testosteron < 11nmol/L

Who cannot take part

  • Any supplementation containing vitamin D alone or in combination within 2 months before the screening visit and during the study
  • The use of medications affecting bone turnover (cholecalciferol, vitamin K, bisphosphonates, anti-epileptic medication, corticosteroid use, heparin)
  • Known bone disease (osteoporosis, Paget disease, primary hyperparathyroidism)
  • Chronic liver failure defined as GOT/GPT > 2N
  • A history of orchidectomy
  • Chronic renal failure defined as eGFR less than 60 mL/min/1.73 m2 for three or more months
  • Hypocalcaemia defined as calcium levels below lower limit of normal range < 2.10 mmol/L
  • Hypomagnesaemia defined as magnesium < 0.65 mmol/L
  • Hypoalbuminemia defined as albumin < 3 g/dL
  • Hypercalcemia defined as > 2.55 mmol/L
  • The use of Testosteron supplementation
  • BMI > 40 Kg/m²
  • Neuroleptic treatment

Where in Belgium

  • UZ BrusselJette, BelgiumTaking people

About the trial

What the trial wants to find out

To increase low free testosteron in men with T2D by vitamin D supplementation. Evaluation of the effect of vitamin D supplementation on the free testosteron level in men with type 2 diabetes and low testosteron level.

Questions to ask the study team

  1. How often do I need to come in, and for how long each time?
  2. Are travel costs paid?
  3. Can I keep my own doctor?
  4. What happens if I want to stop?

Contact the study team: see the registry record

Print a page for my doctor

Data and sources

Registry record
Listed on the EU's official list of trials (CTIS).
Official title
Vitamin D Supplementation to increase free testosterone in Type 2 Diabetes Mellitus men: a Placebo-controlled Randomized Clinical Trial
Plain-language title
Tests vitamin D supplements for low free testosterone in men with type 2 diabetesGenerated from the registry record. The registry title is the official one.
AI summary
From the trial's eligibility criteria. Read by machine on 9 November 2026.
Record updated
27 October 2026