About this trial
Vitamin D deficiency remains a global public health issue (Wilson 2017). In the United Kingdom (UK). There is a lack of research looking at vitamin D status of the British African-Caribbean population. This population is particularly at risk to vitamin D deficiency due to possessing a skin type which hinders the production of vitamin D in the skin. Further, due to the geographical location of the UK, there is reduced ability to produce vitamin D due to the low sun exposure (Libon 2013 ). Our main source of vitamin D is through skin exposure to the sun. In the UK, the UV radiation is only strong enough in April-September (Wilson 2017) for the production of vitamin D to occur. In winter months, vitamin D needs to be consumed in food or supplement form. Vitamin D is essential for healthy bones and is associated with reduced risk of certain cancers and immune disorders (Wilson 2017). There is strong epidemiological evidence linking low vitamin D status with diabetes, cardiovascular disease, osteoporosis, osteoarthritis and some cancers (NatCen 2018).
This observational study will aim to determine the vitamin D status of British Afro-Caribbean women, as well as determine the effects of sun exposure, dietary vitamin D intake, muscular strength, lifestyle and anthropometrical (height, weight etc.) factors have on vitamin D status. The study will be conducted at the University of Surrey. The study will take place in Autumn and winter 2019/2020 and a repeat study in Spring 2020. Each participant will require two visits to the university, each session will take approximately 2 hours. The study is funded by the University of Surrey. The findings of this study may lead to strategies for improving vitamin D status in this population, as well as improving guidelines to assist darker-skinned people regarding sunlight exposure in high latitudes.
Eligibility criteria
This trial accepts healthy volunteersQualifiers
Women
British African-Caribbean Self-reported Having African ancestral origin and migrated via the Caribbean islands, or having at least one parent with African ancestral origin that migrated via the Caribbean
Living in England for >2 months
Aged 18-35 or >55 years
Disqualifiers
Women in perimenopause or menopause
Pregnant or planning pregnancy during study period
Hypercalcaemia (>2.5mmol/L) - assessed and excluded at baseline
Currently receiving treatment for medical conditions that are likely to affect vitamin D metabolism (osteoporosis, hormone replacement therapy, anti-estrogens treatment, antiepileptic drugs and breast cancer treatment)
Trial population
The study population is women aged over 18, who are not in menopause. Healthy women who have African-Caribbean ancestry, and have lived in the UK for more than 2 months are eligible.
Trial design
Ecologic or community
Cross-sectional
Treatments tested in this trial
N/A - no intervention. Observational study.
Other interventionN/A - no intervention. Observational study.
Treatment groups
Trial outcomes
Primary outcomes
Vitamin D (serum 250HD) status
A blood sample will be taken from participants. This will be analysed using liquid chromatography tandem mass spectroscopy (LC-MS)
Change in vitamin D status
A blood sample will be taken from participants. This will be analysed using liquid chromatography tandem mass spectroscopy (LC-MS)
Bone mineral composition
Peripheral computed tomography (pQct) scan
Dual energy X-ray absorptiometry (DEXA) of whole body
Assess bone mineral density
Secondary outcomes
Anthropometrical measurements - weight
Weight (kg)
Anthropometrical measurements - change in weight
measurement of weight (kg)
Anthropometrical measurements - height
measurement of standing height (cm)
Anthropometrical measurements - Hip circumference
measurement of hip (cm)
Sponsors and contacts
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