The Effect of Body Weight on Vitamin D Metabolism

NCT02629198 | Completed

• 1 other identifier: STH16353
• Study Type: observational
• Target: 112
• Locations: 0 countries
• Sites: N/A

Brief Summary

There is current interest in the role of vitamin D in the prevention and treatment of many chronic diseases, including osteoporosis, cancer and neurological disease. The majority of vitamin D in the UK comes from the action of sunlight on skin, and very little from dietary sources. Half of the adult United Kingdom (UK) population have vitamin D insufficiency (according to the Institute of Medicine definition). There are still several important unknowns, including what the optimum levels of vitamin D are, and whether the same intake of vitamin D is appropriate for all sections of the population. Low 25(OH)D and high parathyroid hormone (PTH) have been observed in people with high adiposity (obesity), and the summer rise in vitamin D is blunted in obesity. The potential causes of low 25(OH)D levels include an inadequate supply of vitamin D (by reduced sunlight exposure or poor nutrition), the large pool size of adipose tissue or increased metabolic clearance rate. The investigators will measure metabolites of vitamin D and the kinetics of 25(OH)D using stable isotope techniques in lean, overweight and obese men, women and children to establish whether age, gender and obesity affect vitamin D metabolism and clearance rate. If low 25(OH)D in obesity is related to poorer skeletal health and is due to increased clearance of 25(OH)D or large pool size, then total requirements, and hence supplementation requirements, would be larger for obese people than for lean people.

Conditions

Osteoporosis; Obesity

Keywords

Vitamin D

Outcome Measures

Primary Outcomes (1)

• difference in serum 25OHD between groups

  one measurement at study entry (cross-sectional study)

Secondary Outcomes (4)

• difference in 25OHD half-life between groups using the stable isotope tracer method

  one measurement at study entry (cross-sectional study)

• difference in mean sunlight exposure score between groups (questionnaire)

  one measurement at study entry (cross-sectional study)

• difference in mean dietary vitamin D intake between groups (diet diary)

  one measurement at study entry (cross-sectional study)

• difference in mean of other serum vitamin D metabolites and measures between groups

  one measurement at study entry (cross-sectional study)

Study Arms (3)

normal weight

Healthy men and women ages 25-40 and 55-75. BMI 18.5 to 25.0

overweight

Healthy men and women ages 25-40 and 55-75. BMI 25.0 to 30.0

obese

Healthy men and women ages 25-40 and 55-75. BMI over 30

Eligibility Criteria

• Age: 8 Years - 77 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

The total study sample will consist of 136 participants (112 adults and 24 children) who are lean, overweight or obese. Participants will be drawn from two previous studies; 'The effects of obesity on bone structure and strength' (STH 15688) and 'Body weight and bone' (STH16199), in which their body composition, bone strength and biochemistry have been documented in detail. All participants from the previous studies will be invited to participate, and recruitment will continue until 112 adults and 24 children across a range of body weights have been recruited.

You may qualify if:

• Caucasian
• BMI of 18.5 kg/m2 or above for adults, 2nd-91st centile or above 98th centile for children
• Ages 8 to 15 (children), 16 to 42 years (and premenopausal if female) or 55 to 77 years (and postmenopausal (at least 5 years since last menstrual period (LMP) if female)
• Able and willing to participate in the study and provide written informed consent Completed either STH15688 or STH16199 and gave consent to be approached about future studies

You may not qualify if:

• History of any long term immobilization (duration greater than three months)
• Current confirmed or possible pregnancy (urinary pregnancy test if LMP \>28 days)
• Previously-diagnosed diabetes mellitus
• History of or current conditions known to affect bone metabolism, including
• Diagnosed skeletal disease
• Chronic renal disease
• Malabsorption syndromes
• Diagnosed endocrine disorders
• Hypocalcemia or hypercalcemia
• Diagnosed restrictive eating disorder Use of medications or treatment known to affect bone metabolism, including
• Depot medroxyprogesterone or the combined oral contraceptive pill
• Alcohol intake of greater than 21 units per week
• Competitive athlete, defined as participating in competitive sport at amateur or professional level
• Holiday with significant sunlight exposure in the last six weeks

Sponsors & Collaborators

• Sheffield Teaching Hospitals NHS Foundation Trust: lead
• Department of Health, United Kingdom: collaborator
• University of Sheffield: collaborator
• MRC Human Nutrition Research: collaborator

Biospecimen

Retention: SAMPLES WITH DNA

serum, plasma, urine, DNA

MeSH Terms

Conditions

Osteoporosis; Obesity

Condition Hierarchy (Ancestors)

Bone Diseases, Metabolic; Bone Diseases; Musculoskeletal Diseases; Metabolic Diseases; Nutritional and Metabolic Diseases; Overweight; Overnutrition; Nutrition Disorders; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Jennifer S Walsh, MBChB PhD

  University of Sheffield

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: ECOLOGIC OR COMMUNITY
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: December 7, 2015
• First Posted: December 14, 2015
• Study Start: October 1, 2012
• Primary Completion: April 1, 2013
• Study Completion: April 1, 2013
• Last Updated: December 14, 2015

Record last verified: 2015-12

Data Sharing

• IPD Sharing: Will not share