CompletedInterventional

VITDALIZE UK: Effect of high-dose vitamin D3 on 28-day mortality in adult critically ill patients with severe vitamin D deficiency

VITDALIZE UK is a clinical trial exploring whether high doses of vitamin D can help critically ill adults recover. Low vitamin D is very common in patients who are admitted to intensive care units (ICU). Doctors know that having low vitamin D is linked to higher infection rates and poorer outcomes, but they do not yet know if replacing it directly improves recovery. Patients taking part will receive either vitamin D or a dummy treatment (placebo) alongside their normal hospital care. The trial tracks participants for one year to see if the treatment improves survival, reduces the time spent in hospital, and supports long-term quality of life. Vitamin D is inexpensive and widely available, so if the results are positive, this simple treatment could quickly become standard NHS practice for people who are severely unwell in hospital.

At a glance

Status

Completed

Sponsor

Medical University of Graz

Enrolment target

2,400

Start

02 May 2021

Estimated completion

29 May 2026

Vitamin D deficiency

What is this study about?

When people become critically ill and need care in an intensive care unit (ICU), their bodies are under immense stress. Doctors have noticed that about 70% of these patients have very low levels of vitamin D. While vitamin D is best known for keeping bones and muscles healthy, it also plays a key part in how the immune system fights off severe infections. At the moment, medical teams do not know whether low vitamin D makes people more unwell, or if being very unwell causes vitamin D levels to drop.

Because there are currently no clear NHS guidelines on treating low vitamin D in intensive care, researchers have set up the VITDALIZE trial. This large study is taking place across Europe, with 600 patients joining in the UK. The goal is to discover whether giving high doses of vitamin D helps very sick patients survive, recover faster, and spend fewer days in the hospital.

If the study shows that vitamin D makes a real difference, hospitals could introduce it into routine care very quickly. Vitamin D is safe, low-cost, and easy to store and give. Finding out for certain could improve care for thousands of critically ill people in the future.

Key takeaways

Tests whether high-dose vitamin D helps critically ill adults recover in intensive care.
Open to adults aged 18 and over with very low vitamin D levels admitted to an ICU.
Participants receive either vitamin D or a dummy liquid supplement for up to 90 days.
Follow-up lasts for one year, mainly through brief chats in hospital or short phone calls.
Taking part is completely voluntary and does not stop any standard medical care.

Who may be eligible?

This trial is for adults aged 18 and over who have recently been admitted to an intensive care unit (ICU) within the last three days. To be eligible, the person must be expected to stay in the ICU for at least two days, and blood tests must confirm that their vitamin D levels are very low.

People cannot join if they are unable to absorb liquid medication through their stomach or feeding tube, or if they are in the very final stages of life. The study also excludes anyone with high blood calcium levels, a recent history of kidney stones, active tuberculosis, or sarcoidosis within the past year. Pregnant or breastfeeding women, people with known allergies to the study supplement, and prisoners are also not able to take part.

Could this study suit you?

Answer these quick questions to see if you may be eligible. This is a guide only — the research team makes the final call.

Aged 18 or older
Admitted to an intensive care unit (ICU) within the last 72 hours
Expected to stay in the ICU for at least 48 hours
Blood tests confirm severely low vitamin D levels
Able to receive medicines through the mouth or a feeding tube
No history of kidney stones or high calcium in the past year

Answer every question to see your result.

What does participation involve?

If a patient joins the trial, they will be randomly chosen by a computer to receive either high-dose vitamin D or a dummy dose (placebo) with no active medicine. Neither the patient nor the medical team will know which one they receive. The first dose is given by mouth or feeding tube right away, followed by smaller daily doses for 90 days. Taking part will not interrupt or change the rest of their standard hospital care.

The research team checks in with participants up to six times over one year: on days 0, 5, 12, 28, 90, and at the 12-month mark. If the patient has already left the hospital, follow-up checks are done simply over the phone with brief questions about their recovery. A routine blood sample is taken on day 5 to see how the body is responding. Participants can also choose whether to give a few extra small blood samples for future research, but this is entirely optional.

Potential risks and benefits

Participants might not experience any direct health benefit from taking part, though they may receive vitamin D that corrects a severe deficiency. The main benefit is helping doctors discover better treatments for future intensive care patients. Vitamin D is generally very safe, but giving higher doses carries a small chance of raising blood calcium levels, which the hospital team monitors carefully. Taking part is completely voluntary. Patients or their representatives can leave the trial at any time without their usual medical care being affected in any way.

Locations (28)

Some site locations are approximate. We're improving this — please verify with the trial team before travelling.

University Hospitals Birmingham NHS Foundation Trust
City only
Birmingham, England
South Tees Hospitals NHS Foundation Trust
City only
Cleveland, England
Bolton NHS Foundation Trust
City only
Bolton, England
Guy's and St Thomas' NHS Foundation Trust
City only
London, England
Belfast Health & Social Care Trust
City only
Belfast, Northern Ireland
Mid Yorkshire Hospitals NHS Trust
Unverified
Wakefield, England
East Lancashire Hospitals NHS Trust
Unverified
Blackburn, England
Great Western Hospitals NHS Foundation Trust
Unverified
Swindon, England
Diana, Princess of Wales Hospital
Unverified
Grimsby, England
Derriford Hospital
Unverified
Plymouth, England
Royal Bournemouth Hospital Bcsc
Unverified
Bournemouth, England
Sandwell and West Birmingham Hospitals NHS Trust
Unverified
Birmingham, England

Common questions

What is a placebo?

A placebo is a harmless dummy treatment designed to look just like the real medicine but containing no active ingredient. It helps researchers tell if the actual vitamin D is truly responsible for any health improvements.

Will taking part change my normal intensive care treatment?

No. You will continue to receive all standard medications, breathing support, and care that your intensive care team provides.

Can family members give consent if the patient is too unwell?

Yes. In intensive care, patients are often too poorly to make decisions. In these cases, doctors can ask a close family member or legal representative to agree on their behalf until the patient is well enough to decide for themselves.

Do I have to pay for the study treatment?

No. All study treatments, extra tests, and follow-up checks are provided entirely free of charge as part of NHS-supported research.

What happens after the patient leaves hospital?

If you are discharged before the trial ends, the team will continue to contact you by phone at set points up to one year to ask a few simple questions about your health and recovery.

How to find out more

Dhruv Parekh

d.parekh@bham.ac.uk - Official trial record

Always speak to your GP or specialist before deciding to take part in a study.