FAQ

How long does the study go for and when will you get results?

Will I be advised in the future if I have been taking a vitamin D or placebo tablet?

I have moved. Can I continue and how do I update my contact details?

Am I taking the same tablets each year (i.e., vitamin D or placebo)?

I missed my tablet on the 1st of the month what should I do?

I donít get the reminder anymore, am I still on the study?

I am going away. Can I take the tablets with me?

Is it OK for me to donate blood?

What if I am taking the placebo tablet? How do I make sure I am not vitamin D deficient?

I have started taking a new medication. How do I make sure it is OK to take the D-Health Trial tablets while taking this medication?

I have been diagnosed with a new disease. Should I continue taking the D-Health Trial tablets?

I must be taking the placebo because I donít feel any different. Is there any point in me continuing?

How do you get results? You havenít done any testing on me?

Why arenít you measuring my vitamin D level?

Why donít you ask about lifestyle, sun exposure or diet in the yearly surveys?

How is the trial benefitting me?

Iíve got more questions. How do I get to talk to somebody senior?


How long does the study go for and when will you get results?  

We are asking people to take tablets for 5 years Ė the last people who joined the study will finish in June 2020. This seems like a long time, but we need people to take the vitamin D for long enough for it to have any effects on health. If it is beneficial it might have relatively fast effects on things like infection but it would take a longer time to affect things like heart disease. We hope to generate some results about short-term effects in 2017. We will make sure that all results are in our newsletters and on our website.

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Will I be advised in the future if I have been taking a vitamin D or placebo tablet?

Yes. When everybody has finished taking tablets we will tell you what you were taking.

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I have moved. Can I continue and how do I update my contact details?

Yes you can definitely continue. Please give us a call or email with your new details.

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Am I taking the same tablets each year (i.e., vitamin D or placebo)?

Yes we make sure you that you get the same tablet type each year.

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I missed my tablet on the 1st of the month what should I do?

You can take your tablet any time up to the 10th of the month. If you donít take it before then just put the tablet for that month in the bin and start again on the first day of the following month

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I donít get the reminder anymore, am I still on the study?

Please let us know if you have stopped getting reminders. This can occur if you have changed phone numbers or your email address

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I am going away. Can I take the tablets with me?

Yes, but you might like to take a letter with you confirming what these tablets are. Please let us know if you would like us to send you a letter

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Is it OK for me to donate blood?

Yes it is fine for you to donate blood but the blood bank may request a letter from us. Please contact us if you need this

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What if I am taking the placebo tablet? How do I make sure I am not vitamin D deficient?

The Australian nutrition guidelines are that if you are rarely exposed to the sun you should take 400 IU of vitamin D per day if you are under 70 years old and 600 IU per day if you are 70 or older. This is consistent with the recommendations in other countries and provides sufficient vitamin D to avoid the known health problems associated with vitamin D deficiency.


Most people get about 100 IU per day from food so we encourage you to restrict your supplementary intake to 500 IU per day. If your doctor advises you to take more than that please give us a call

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I have started taking a new medication. How do I make sure it is OK to take the D-Health Trial tablets while taking this medication?

It is usually fine to keep taking the D-Health trial tablets while taking other medications. However, you should tell your doctor you are part of the trial. If you have lost your card for doctors please let us know and we will send you a new one. You can also call us for advice

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I have been diagnosed with a new disease. Should I continue taking the D-Health Trial tablets?

In most situations there is no problem with continuing. However, you should let your doctor know you are participating and ask for their advice. We are happy to chat to your doctor if they would like

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I must be taking the placebo because I donít feel any different. Is there any point in me continuing?

It is most likely that vitamin D has no effect on how you feel in the short term. This is because vitamin D may have effects that canít be felt. In the longer term it might reduce risk of diseases like cancer and heart disease. The D-Health Trial and a few other trials happening around the world will help us to understand whether or not it has any of these longer term effects.


Some people do think that taking vitamin D makes them feel better. However, this is not yet proven. We ask about how you feel in our annual surveys so that we can try and get an answer about whether or not vitamin D might make you feel different

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How do you get results? You havenít done any testing on me?

We aim to compare the health of the two groups in the trial, the placebo group and the vitamin D group. For example, if the proportion of people who get cancer in the vitamin D group is lower than the proportion in the placebo group, we know that vitamin D has reduced the risk of cancer. We can find out about many conditions like cancer and heart disease from databases such as the Australian Cancer Registry or hospital files.


We also ask you about various health outcomes in our annual surveys. The questions we ask about things like mood and pain are standardised Ďtestsí

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Why arenít you measuring my vitamin D level?

The aim of the study is to see if changing the AVERAGE vitamin D level in a population changes health outcomes such as cancer and heart disease. The aim is not to see if we can change vitamin D levels, or if achieving a certain vitamin D level influences health.

The average vitamin D level before starting the study would have been the same in the two groups because we randomly assigned people to one or the other group. We test vitamin D levels in a random sample of about 800 D-Health participants every year to check that we are now seeing a difference in the average level of the two groups. A diagram that explains the study design can be found by clicking on the link below

Study Design

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Why donít you ask about lifestyle, sun exposure or diet in the yearly surveys?

This is because we are interested in comparing the two groups in the study and we know that the lifestyle factors are equally distributed in the two groups. For example, the proportion of people who spend a lot of time outside in the vitamin D group will be the same as the proportion in the placebo group. We asked about these factors in the survey you did before you started and will take account of these in our data analysis

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How is the trial benefitting me?

Participating in medical research does not necessarily benefit you. Medical research is about generating evidence that can improve the health of other people in the future

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Iíve got more questions. How do I get to talk to somebody senior?

We have a number of very knowledgeable senior staff. Just give us a call and let our staff member know that you would like to talk to one of our seniors. If they canít help, they will put you through to the chief investigator, Dr Rachel Neale.

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