Plain English Summary
Background and study aims
At present the UK government only recommends a level of dietary vitamin D for people aged over 65 or people who may be at risk of vitamin D deficiency. This could include people that rarely spend time outside or cover up if they do go outside. However, for normal adults, it is assumed that all the necessary vitamin D will come from sunshine. In the UK we do not have enough sunlight of the correct wavelength in the winter months to make vitamin D in our skin. Therefore, because there are few foods that naturally contain vitamin D, our vitamin D stores tend to decrease during winter. We would like to investigate what happens to vitamin D levels throughout the year in the North of Scotland.
The aim of this project was to measure vitamin D status in healthy postmenopausal women aged <65 years, over at least one year; to assess vitamin D deficiency at different seasons; and to assess the relative contributions of sunlight exposure and diet to vitamin D status at each season.
Who can participate?
Healthy postmenopausal women aged between 55 -65 years living in the Aberdeen area.
What does the study involve?
There are no treatments involved in this study. Once every three months for 15 months (five visits in total) starting in Spring 2006 participants visit our unit for a fasting blood sample to assess vitamin D status. Some of this sample will be stored for possible future analysis of diet or bone markers. We will use a handheld colorimeter (a device similar to a camera) to measure skin colour, which may gradually change over the period of the study depending on the amount of sunlight. We will also measure grip strength by asking the participant to squeeze a small metal bar for a few seconds, as muscle strength may change depending on vitamin D status.
After each visit participants will be asked to complete a food questionnaire or food diary for 7 days along with a physical activity questionnaire. They will also be asked to wear a small badge on the lapel of the outside coat or jacket for 7 days which will monitor the amount of sunlight they will be getting in a week. They will be asked to complete a sunlight exposure and falls diary.
A subset of women will be asked if they would also be prepared to wear an accelerometer for 7 days after each visit. An accelerometer is a non-invasive device the size of a pager that is worn on the waist and measures body movement.
During the course of the study the participant will have the opportunity to have two bone scans, one in the autumn and one the following spring. After the second scan the results of both scans will be reported to your GP.
What are the possible benefits and risks of participating?
There are no direct benefits, besides the information they will receive from their GP about their bone health after the bone scan. There are no side effects except those associated with having a blood sample taken. There is minor radiation exposure with the bone scan (similar to background radiation in Aberdeen).
Where is the study run from?
The University of Aberdeen.
When is study starting and how long is it expected to run for?
The study started in March 2006 and has ended. It lasted for 15 months and participants were asked to attend an additional one-off visit in Spring 2008, to allow comparison of vitamin D status across three spring periods (when vitamin D status is likely to be at its lowest).
Who is funding the study?
The study was funded by the UK Food Standards Agency.
Who is the main contact?
Dr Helen Macdonald
h.macdonald@abdn.ac.uk
Trial website
Contact information
Type
Scientific
Primary contact
Dr Helen Macdonald
ORCID ID
Contact details
Osteoporosis Research Unit
Health Sciences Building
Forestehill
Aberdeen
AB25 2ZD
United Kingdom
+44 (0)1224 559001
h.macdonald@abdn.ac.uk
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
Food Standards Agency ref no: N05062
Study information
Scientific title
Acronym
ANSaVID (Aberdeen Nutrition Sunlight and VItamin D study)
Study hypothesis
To establish whether diet and previous summer's sunlight exposure maintain vitamin D levels at northerly latitudes of the United Kingdom (UK) and determine how much dietary vitamin D is required (if any).
Ethics approval
Approval received from the National Health Service Research Ethics Committee (NHS REC): Grampian Local Research Ethics Committee on the 13th January 2006 (ref: 05/S0802/149).
Study design
Observational longitudinal study - single centre
Primary study design
Observational
Secondary study design
Cohort study
Trial setting
Not specified
Trial type
Quality of life
Patient information sheet
Condition
Low bone mass/risk of osteoporosis
Intervention
This is a 15-month observational study starting in March 2006 aiming to assess how diet and sunlight exposure influence vitamin D status for each three-monthly season. There will be five visits in total.
All women will complete food diaries, sunlight exposure and falls diaries, physical activity questionnaires, and have grip strength assessed at three-month intervals (five visits in total) and wear sunlight exposure badges for one week every three months. There will also be a quantitative measure of sunlight exposure using a hand held spectrophotometer/chromometer which measures skin colouration. At each visit the women will be asked if they will provide a blood sample for measurement of 25-hydroxy vitamin D (a marker of vitamin D status) and bone turnover markers. All women will be offered two bone mineral density scans: the first in the autumn and the second the following spring.
A subgroup of women (n = 48) will use accelerometers for one week every three months to estimate physical activity in more detail.
Intervention type
Other
Phase
Not Specified
Drug names
Primary outcome measure
Monitor longitudinally the seasonal variation in vitamin D status at a northerly latitude, assessing the individual contributions of sunlight and diet.
All primary and secondary outcomes were measured at each visits, i.e., at Baseline (BL), 3-month, 6-month, 9-month and 12-month visits.
Secondary outcome measures
1. Monitor seasonal variation in physical activity (confounder of vitamin D status)
2. Monitor seasonal variation in:
2.1. Markers of bone turnover (functional marker)
2.2. Falls, muscle strength (functional markers not related to bone health)
3. Determine the relationship between vitamin D status, functional markers (Bone Mineral Density [BMD], bone resorption, muscle strength) with and without adjustment for physical activity level
All primary and secondary outcomes were measured at each visits, i.e., at Baseline (BL), 3-month, 6-month, 9-month and 12-month visits; BMD was measured at 6-month and 9-month visits only.
Overall trial start date
01/01/2006
Overall trial end date
31/10/2008
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
Women from a previous sceening study (Aberdeen Prospective Osteoporosis Screening Study - APOSS) aged less than 65 years.
Participant type
Patient
Age group
Adult
Gender
Female
Target number of participants
360
Participant exclusion criteria
Participants will be excluded if they:
1. Have chronic gastro-intestinal disease associated with malabsorption
2. Are taking oral corticosteroids
3. Are receiving bisphosphonate therapy (as there is a possibility of interaction with vitamin D metabolism)
Recruitment start date
01/01/2006
Recruitment end date
31/10/2008
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Osteoporosis Research Unit
Aberdeen
AB25 2ZD
United Kingdom
Sponsor information
Organisation
Food Standards Agency (UK)
Sponsor details
Aviation House
125 Kingsway
London
WC2B 6NH
United Kingdom
saadia.noorani@foodstandards.gsi.gov.uk
Sponsor type
Industry
Website
Funders
Funder type
Industry
Funder name
Food Standards Agency (UK) (ref: N05062)
Alternative name(s)
FSA
Funding Body Type
private sector organisation
Funding Body Subtype
Other non-profit organizations
Location
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. 2011 results in http://www.ncbi.nlm.nih.gov/pubmed/21411556
Publication citations
-
Results
Macdonald HM, Mavroeidi A, Aucott LA, Diffey BL, Fraser WD, Ormerod AD, Reid DM, Skin color change in Caucasian postmenopausal women predicts summer-winter change in 25-hydroxyvitamin D: findings from the ANSAViD cohort study., J. Clin. Endocrinol. Metab., 2011, 96, 6, 1677-1686, doi: 10.1210/jc.2010-2032.