This site became the new on June 19th. Learn more.
Show more Menu IMPORTANT: Listing of a study on this site does not reflect endorsement by the National Institutes of Health. Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu IMPORTANT: Talk with a trusted healthcare professional before volunteering for a study. Read more... Menu
Give us feedback

Dietary Supplementation With 25-hydroxyvitamin D3 in Older Adults

This study has been completed.
Information provided by (Responsible Party):
Kevin D. Cashman, University College Cork Identifier:
First received: July 18, 2011
Last updated: November 30, 2015
Last verified: November 2015
The purpose of this study is to investigate whether a supplement of 25-hydroxyvitamin D is five-times more potent in raising vitamin D status (as reflected by serum 25(OH)D) compared to an equivalent amount of vitamin D3 in older adults. It will entail a 10 week supplementation study during winter months.

Condition Intervention
Vitamin D Status as Reflected by Serum 25-hydroxyvitamin D Dietary Supplement: vitamin D3 Dietary Supplement: 25-hydroxyvitamin D3 Dietary Supplement: 25-hydroxyvitamin D (20 microgram/day) Dietary Supplement: Placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Prevention
Official Title: Comparison of the Bioefficacy of Oral 25-hydroxyvitamin D3 and Vitamin D3 Supplements on Vitamin D Status in Older Adults

Resource links provided by NLM:

Further study details as provided by Kevin D. Cashman, University College Cork:

Primary Outcome Measures:
  • serum 25-hydroxyvitamin D concentration [ Time Frame: 10 weeks ]

Secondary Outcome Measures:
  • serum parathyroid hormone [ Time Frame: 10 weeks ]
  • blood pressure [ Time Frame: 10 weeks ]
  • biochemical markers of bone turnover [ Time Frame: 10 weeks ]
  • serum calcium adjusted for albumin [ Time Frame: 10 weeks ]

Enrollment: 56
Study Start Date: January 2011
Study Completion Date: September 2011
Primary Completion Date: July 2011 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Vitamin D3 (20 microgram/day) Dietary Supplement: vitamin D3
20 micrograms per day for 10 weeks
Active Comparator: 25-hydroxyvitamin D (7 microgram/day) Dietary Supplement: 25-hydroxyvitamin D3
7 microgram/day for 10 weeks
Active Comparator: 25-hydroxyvitamin D3 (20 micogram/day) Dietary Supplement: 25-hydroxyvitamin D (20 microgram/day)
20 microgramday for 10 weeks
Placebo Comparator: Placebo Dietary Supplement: Placebo
0 ug vitamin D3/25-hydroxyvitamin D3/day for 10 weeks

Detailed Description:
The UK (McCance & Widdowson) food composition tables suggests that 25-hydroxyvitamin D (which is present in some foods, albeit at very low concentrations, but which is also commercially available) may possess up to 5-times the activity of native vitamin D3 in food. Thus, in theory, each micogram of 25-hydroxyvitamin D consumed in the diet could boost vitamin D status up to five times most effectively compared to each microgram of native vitamin D in food. It is worth noting, however, that estimates of potency range from 2 to 5, depending on approach used, and that the real potency needs to be confirmed in a human study. This study aims to examine the biological activity of 25-hydroxyvitamin D (i.e., its potency relative to vitamin D3) as well as its effect on selected functional markers in a randomised, double-blind, human intervention trial in older adults.

Ages Eligible for Study:   45 Years and older   (Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Subjects will be eligible if they are 45+ years of age
  • Body Mass Index (BMI) 19-30

Exclusion Criteria:

  • have hypercalcaemia
  • chronic illness
  • renal or liver disorders
  • taking medications that might interact with vitamin D or metabolite
  • drank more than > 21 standards (male)/ 14 standards (female) of alcohol per week
  • planning to change smoking habits
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01398202

University College Cork
Cork, Ireland
Sponsors and Collaborators
University College Cork
Principal Investigator: Kevin D Cashman, PhD University College Cork
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Kevin D. Cashman, Professor of Food and Health, University College Cork Identifier: NCT01398202     History of Changes
Other Study ID Numbers: 111
Study First Received: July 18, 2011
Last Updated: November 30, 2015

Keywords provided by Kevin D. Cashman, University College Cork:
Vitamin D status
25-hydroxyvitamin D
Vitamin D3

Additional relevant MeSH terms:
Vitamin D
Growth Substances
Physiological Effects of Drugs
Bone Density Conservation Agents processed this record on August 18, 2017