Vitamin D and Longevity (VIDAL) Trial: randomised feasibility study v1

• Research type

  Research Study

• Full title

  Feasibility study including a double blind (C)controlled study and an open label (C) controlled study for a larger randomised trial measuring the effect of oral vitamin D (I) on morbidity and mortality (O) in men and women aged 65-84 (P)

• IRAS ID

  84945

• Contact name

  Adrian Martineau

• Sponsor organisation

  London School of Hygiene & Tropical Medicine

• Eudract number

  2011-003699-34

• ISRCTN Number

  ISRCTN46328341

• Research summary

  This is a feasibility study for a larger trial. The question the main trial will address is whether vitamin D supplementation reduces morbidity and increases lifespan in men and women aged 65-84. Many people in the UK do not receive enough sun exposure to achieve a satisfactory vitamin D blood level. Epidemiological evidence suggests that people with low vitamin D levels are at increased risk for several diseases, including heart disease, various infections and some types of cancer. However, similar epidemiological evidence of benefit for various other vitamins was disproved when randomized trials were conducted. We are therefore planning a large (n=20,000) trial to evaluate the effect of vitamin D supplementation on mortality and morbidity among older members of the general population. For the primary endpoint of overall mortality in the main trial the necessity of placebo-control is not clear. This feasibility study, which is funded by the Government??s Health Technology Assessment agency, will compare a placebo-controlled trial in 10 GP practices against an open randomised trial in 10 practices, randomising 800 people aged 65-84 double-blind to monthly placebo versus monthly vitamin D for 2 years, and 800 to no treatment versus 2 years of monthly vitamin D. To decide whether the main trial should have a placebo control group, we shall compare participant acceptability, costs, treatment compliance and recruitment rates with the two approaches, as well as studying the effect of treatment on vitamin D blood levels. Participants will (i) visit their GP practice twice (at entry and at 2 years) to answer a few lifestyle questions and provide a blood sample; and (ii) reply to a brief communication every 3 months during the 2-year study period. Those allocated to vitamin D (100,000 IU per month) or placebo will take oral study medication once a month for 2 years.

• REC name

  London - Chelsea Research Ethics Committee

• REC reference

  11/LO/1989

• Date of REC Opinion

  20 Dec 2011

• REC opinion

  Favourable Opinion