The Relationship Between Sun Exposure, Diet, Lifestyle and Bone on Vitamin D Status (25OHD) in British African-Caribbean Women Living in Southern United Kingdom
试验速览
- 阶段
- 不适用
- 状态
- 招募中
- 入组人数
- 100
- 试验地点
- 1
- 主要终点
- Dual energy X-ray absorptiometry (DEXA) of whole body
研究概览
简要总结
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.
详细描述
Introduction
Vitamin D deficiency remains a global public health issue (Wilson 2017). There is strong epidemiological evidence linking low vitamin D status with diabetes, cardiovascular disease, osteoporosis, osteoarthritis and some cancers (NatCen 2018). The condition has a significant financial impact on the economy, therefore is of public health importance (Sturges 2018).
The British African-Caribbean population in the United Kingdom (UK) is steadily increasing (2011 UK census). Despite this, there is a lack of research looking at the vitamin D status of this 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 (Libon 2013). Further, due to the geographical location of the UK, there is an even greater 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 between April and September, for the production of vitamin D to occur (Wilson 2017). In winter months, vitamin D needs to be consumed in food or supplement form. Our study will look at the vitamin D status of British African-Caribbean women living in the UK in late autumn and winter 2019/2020 and compare these findings to a second sample in spring 2020. In addition, the investigators will determine which factors such as dietary intake, sun exposure and muscular strength contribute to vitamin D status. Each participant will require two visits to the university, the first session will take approximately 2 hours, while the second session will be shorter as not all measures will be repeated. 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.
研究设计
- 研究类型
- Observational
- 观察模型
- Ecologic Or Community
- 时间视角
- Cross Sectional
入排标准
- 年龄范围
- 18 Years 至 —（Adult, Older Adult）
- 性别
- Female
- 接受健康志愿者
- 是
入选标准
- •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
- •No significant health issues
- •Pre-menopausal (regular menstrual periods) or Post-menopausal (menstrual periods stopped for longer than 12 consecutive months)
- •BMI 18-30kg/m2
排除标准
- •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)
- •Regular use of sun beds
- •Having a sun holiday one month prior to commencing study or plans for a sun holiday for more than 4 weeks within the study period
- •Women who take vitamin D or calcium supplements (or multivitamin supplements that contain these vitamins) - If potential participant agrees to stop supplement use to join the study, a wash-out period of 8 weeks prior to commencing the study is acceptable
- •Living in England for less than 2 months
结局指标
主要结局
Dual energy X-ray absorptiometry (DEXA) of whole body
时间窗: One measurement at baseline
Assess bone mineral density
Dual energy X-ray absorptiometry (DEXA) of femoral head
时间窗: One measurement at baseline
Assess fracture risk
Vitamin D (serum 250HD) status
时间窗: One measurement at baseline
A blood sample will be taken from participants. This will be analysed using liquid chromatography tandem mass spectroscopy (LC-MS)
Change in sun exposure from winter to spring
时间窗: The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.
sun exposure will be measured by a dosimeter which measures UVB exposure. Participants wear this like a badge, for 4 days after the study
Change in blood bone marker
时间窗: The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.
CTX (bone marker) will be measured from blood
Vitamin D intake
时间窗: One measurement at baseline
Vitamin D intake will be measured through a 4-day food diary which participants will fill out for 4 day at home after the study
Bone mineral composition
时间窗: One measurement at baseline
Peripheral computed tomography (pQct) scan
Change in vitamin D status
时间窗: The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.
A blood sample will be taken from participants. This will be analysed using liquid chromatography tandem mass spectroscopy (LC-MS)
Change in vitamin D intake
时间窗: The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.
Vitamin D intake will be measured through a 4-day food diary which participants will fill out for 4 day at home after the study
Sun exposure
时间窗: One measurement at baseline
sun exposure will be measured by a dosimeter which measures UVB exposure. Participants wear this like a badge, for 4 days after the study
次要结局
- Change in muscular strength - grip-strength test(The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.)
- Sun exposure questionnaire(One measurement at baseline)
- Anthropometrical measurements - height(One measurement at baseline)
- Anthropometrical measurements - weight(One measurement at baseline)
- Anthropometrical measurements - change in waist circumference(The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.)
- Anthropometrical measurements - waist circumference(One measurement at baseline)
- Blood analytes - calcium(One measurement at baseline)
- Blood analytes - change in calcium levels(The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.)
- Blood analytes - change in albumin levels(The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.)
- Blood analytes - lipid profile(One measurement at baseline)
- Blood analytes - change in lipid profile status(The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.)
- Anthropometrical measurements - change in weight(The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.)
- Anthropometrical measurements - change in hip circumference(The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.)
- Blood analytes - albumin(One measurement at baseline)
- Anthropometrical measurements - Hip circumference(One measurement at baseline)
- Blood analytes - change in PTH levels(The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.)
- Lifestyle questionnaire(One measurement at baseline)
- Blood analytes - PTH(One measurement at baseline)
- Blood analytes - blood glucose levels(One measurement at baseline)
- Blood analytes - micronutrient status(One measurement at baseline)
- Blood analytes - change in micronutrient status(The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.)
- Blood analytes - change in blood glucose levels(The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.)
- Muscular strength - sit-to-stand test(One measurement at baseline)
- Change in muscular strength - sit-to-stand test(The first measurement will be performed in winter 2020, with a repeat measurement approximately 3 months later in spring 2020.)
- Muscular strength - grip-strength test(One measurement at baseline)
- International Physical Activity Questionnaire (IPAQ) short form(One measurement at baseline)