Vitamin D and Cognition Study (VITA-D)
Study background
Australia's population is ageing rapidly and so is the frequency of age-related health problems, such as cognitive decline and dementia. Mild Cognitive Impairment (MCI) describes mild memory problems in older adults that are associated with an increased risk of future cognitive decline. There is increasing evidence that cognitive decline can be delayed by targeting potentially modifiable risk factors. Vitamin D is important for healthy bones and muscle function, but is also possibly important for healthy brain function. The purpose of this randomised placebo-controlled clinical trial is to investigate whether supplementation with vitamin D for 18 months in older adults with MCI who have low vitamin D levels, can help to reduce future cognitive decline.
What does it involve for participants?
Screening telephone: If you are 65 years and older and feel your memory has changed, we will ask you a number of screening questions over the phone to find out whether you are eligible. We also will ask you to name a person who knows you well (such as a friend or relative) and may be able to answer some questions over the phone about your memory.
Baseline visit: If you meet the trial's entry criteria we will invite you to a baseline visit at Royal Perth Hospital (RPH). At this visit you will be asked to donate blood (approximately 4 teaspoons) and urine samples (after overnight fasting). These biochemistry tests will determine whether you have low vitamin D concentration (between 12.5 and 50 nmol/L) and to exclude abnormalities which might prevent you participating in the trial. For one of these tests we will isolate your DNA and determine which subtype of a certain protein, called Apolipoprotein E (APOE), you carry. Studies have shown that one APOE subtype is associated with increased risk of memory problems later in life. However, the individual risk is still uncertain and this test cannot be used to work out whether somebody will experience memory deterioration later. If other genes related to memory disorders become apparent during the trial period we might test for these as well. There is a separate consent form relating to DNA tests and detailed information regarding DNA testing is included in a separate section below. After the blood and urine tests you will receive breakfast and then you will be asked to complete some memory tests.
Randomization visit: If your vitamin D concentration is between 12.5 and 50 nmol/L you we will be asked to complete a few more memory tests and questionnaires about your quality of life, general health, diet and activity levels. You will also receive a brief physical assessment of 15-20 minutes duration to measure your height, weight, strength and balance. At the end of this visit you will be randomized (like flipping a coin) to either receiving vitamin D (one tablet with 1000 IU cholecalciferol per day for 18 months) or placebo tablets. During the trial, neither you nor the research staff will know if you are taking vitamin D or placebo. If it is found that you have a low daily calcium intake we might also give you calcium tablets (one tablet per day). This is necessary since Vitamin D needs a minimum concentration of calcium in your body to be effective.
Follow-up visits: During the trial you will be asked to complete 3 more assessments at RPH after 6, 12 and 18 months. These visits will include repeating fasting blood and urine samples, memory tests and physical examination. We will also repeat the 10-minute questionnaire with your friend/relative. At each of these visits you will also receive your trial tablets.
Further information
If you are interested, please contact Cheryl Ackoy on 9224 2855 weekdays, between 9am and 4:30pm. We look forward to receiving your call!
For further information about the trial, you also may view the clickable links below.
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