Condition category
Nutritional, Metabolic, Endocrine
Date applied
Date assigned
Last edited
Retrospectively registered
Overall trial status
Recruitment status
No longer recruiting

Plain English Summary

Background and study aims
Vitamin D is essential for good health, because it helps our bodies to absorb calcium from the diet. There is a lot of evidence that having enough vitamin D can help prevent against many diseases, such as heart disease, bone diseases and cancer. Although vitamins generally come from the diet, in the case of vitamin D, the majority of people actually get most of it from sunlight. When the sun shines on our skin, a reaction in the body is triggered, producing a form of vitamin D called cholecalciferol (also called vitamin D3). Another important form of vitamin D is ergocalciferol (also called vitamin D2), which is produced in plants. Studies have shown that in the winter months, many people in the UK suffer from a lack of vitamin D (vitamin D deficiency) because of the lack of sun exposure. It can be hard to take in vitamin D in the diet, as it is not naturally present in many foods. A possible solution is to fortify food or drink with vitamin D2 or D3. The aim of this study is to find out whether the concentrations of vitamin D in the blood can be maintained by regularly consuming D2 or D3, and if one is better than the other.

Who can participate?
Healthy adults among the staff and students of King’s College London (UK).

What does the study involve?
Participants are randomly allocated into one of five groups. Participants in the first group receive sachets to make hot malted milk drinks (Horlicks) which does not have any extra ingredients (placebo). Participants in the other four groups are also given sachets to make malted milk drinks, but theirs contain additional vitamin D (5ug or 10ug of either D2 or D3). Participants in all groups are asked to drink one sachet every day for four weeks. Blood samples are taken from all participants, twice at the start of the study and then weekly over the four weeks to measure the concentration of vitamin D in the blood.

What are the possible benefits and risks of participating?
Not provided at time of registration.

Where is the study run from?
Metabolic Research Unit, King's College London (UK)

When is the study starting and how long is it expected to run for?
February 2011 to April 2011

Who is funding the study?
GlaxoSmithKline (UK)

Who is the main contact?
Professor Tom Sanders

Trial website

Contact information



Primary contact

Prof Tom Sanders


Contact details

King's College London
Franklin-Wilkins Building
150 Stamford Street
United Kingdom
+44 (0)20 7848 4273

Additional identifiers

EudraCT number number

Protocol/serial number


Study information

Scientific title

Comparison of the bioavailability of vitamin D2 and vitamin D3 in healthy volunteers when consumed at different levels in a malt drink


Study hypothesis

This study will investigate whether the seasonal fall in serum serum 25-hydroxyvitamin D concentrations [25(OH)D] that occurs in the winter months can be prevented by the regular consumption of ergocalciferol or cholecalciferol in a fortified drink.
Vitamin D is a determinant of calcium homeostasis and therefore changes in calcium and parathyroid hormone concentrations were also investigated.

Ethics approval

South East London REC1 February 2011, ref: 10/H0804/91

Study design

Parallel randomized placebo controlled double blind design

Primary study design


Secondary study design

Randomised controlled trial

Trial setting


Trial type

Quality of life

Patient information sheet

Not available in web format, please use the contact details below to request a patient information sheet


Vitamin D supplementation


1. Participants were randomly allocated to placebo or one of 4 experimental treatments of vitamin D:
1.1. 5ug cholecalciferol or
1.2. 5ug ergocalciferol or
1.3. 10ug cholecalciferol or
1.4. 10ug ergocalciferol
2. The vitamin D or placebo was administered as a malted milk drink and consumed once a day for 28 days

Intervention type



Not Applicable

Drug names

Cholecalciferol, ergocalciferol

Primary outcome measure

Change in serum 25(OH)D concentrations

Secondary outcome measures

Change in calcium and parathyroid hormone concentrations

Overall trial start date


Overall trial end date


Reason abandoned (if study stopped)


Participant inclusion criteria

1. Healthy males or females
2. Ages of 18 - 65 years

Participant type


Age group




Target number of participants


Participant exclusion criteria

1. Seated blood pressure >160/105 mm Hg
2. Body Mass Index <18.5 and >35 kg/m2
3. Taking vitamin and mineral supplements (including cod-liver oil), or prescription calcium/vitamin D
4. Recent exposure to high UVB light (since 1 December 2010)
5. Intolerance to study product (lactose, milk protein)
6. Chronic renal, liver or inflammatory bowel disease
7. Diabetes
8. Unwilling to follow the protocol and/or give informed consent
9. Unwilling to restrict consumption of oily fish to no more than 2 portions of oily fish per week

Recruitment start date


Recruitment end date



Countries of recruitment

United Kingdom

Trial participating centre

King's College London
United Kingdom

Sponsor information


GlaxoSmithKline (UK)

Sponsor details

980 Great West Road
United Kingdom

Sponsor type




Funder type


Funder name

GlaxoSmithKline (ref: RHS00976)

Alternative name(s)

GlaxoSmithKline plc., GSK

Funding Body Type

private sector organisation

Funding Body Subtype



United Kingdom

Results and Publications

Publication and dissemination plan

Not provided at time of registration

Intention to publish date

Participant level data

Not provided at time of registration

Basic results (scientific)

Publication list

1. 2012 results in

Publication citations

  1. Results

    Fisk CM, Theobald HE, Sanders TA, Fortified malted milk drinks containing low-dose ergocalciferol and cholecalciferol do not differ in their capacity to raise serum 25-hydroxyvitamin D concentrations in healthy men and women not exposed to UV-B., J. Nutr., 2012, 142, 7, 1286-1290, doi: 10.3945/jn.111.156166.

Additional files

Editorial Notes