Update - results published: 4,000 IU of Vitamin D daily is safe, but takes a year to plateau (Best-D) – RCT Dec 2016
Estimation of the optimum dose of vitamin D for disease prevention in older people: rationale, design and baseline characteristics of the BEST-D trial
Maturitas, Available online 7 February 2015, doi:10.1016/j.maturitas.2015.01.013
Robert Clarkea, 1, Robert.clarke at ctsu.ox.ac.uk , Connie Newmanb, 1, Joseph Tomsona, 1, Harold Hinc, 1, Rijo Kuriena, Jolyon Coxa, Michael Laya, Jenny Sayera, Michael Hilla, Jonathan Embersona, Jane Armitagea, 1, 2
Randomized Controlled Trial underway in England using 4,000, 2,000 IU, and 0 IU doses
No indication as to when results will be published
VitaminDWiki finds various problems with this study
- More vitamin D should be given if person is heavier (but an RCT cannot do this)
- More vitamin D should be given if person is sick, a smoker, etc. (but an RCT cannot do this)
- Should start with a loading dose, otherwise 4-6 months of trial are wasted
- Should include people who are trying to be healthy, i.e. those taking > 400 IU vitamin D/day
- Bone is not built just with vitamin D – should include protein and cofactors
- To get full benefit and minimize risks, should include co-factors such as Magnesium, Vitamin K2, and Omega-3
Highlights
- The BEST-D (Biochemical Efficacy and Safety Trial of vitamin D) trial will compare the biochemical and other effects of daily dietary supplementation with 100 μg or 50 μg vitamin D3 or placebo, when administered for 12 months, in 305 ambulant community-dwelling older people living in Oxfordshire, England.
- The primary analyses will compare 12-month mean plasma concentrations of 25(OH)D as well as the proportion of participants with a 12-month concentration >90 nmol/L between participants allocated 100 μg and participants allocated 50 μg daily. Secondary analyses will compare the two active doses (both separately and when combined) with placebo.
- Additional end-points include biochemical assessments of safety, blood pressure, arterial stiffness, falls, fractures, heel and wrist bone density, grip strength and physical performance and echocardiographic assessments of cardiac function in a random sample of participants.
- The results of this trial will help determine the optimum dose of vitamin D to test in a larger trial investigating whether vitamin D supplementation can reduce the risk of fractures, cardiovascular disease or cancer. .
Background: Previous large trials of vitamin D for prevention of fractures and other disease outcomes have reported conflicting results, possibly because the doses tested were insufficient to maintain optimum blood levels of vitamin D (25[OH]D) predicted by the observational studies. This report describes the design and baseline characteristics of the BEST-D (Biochemical Efficacy and Safety Trial of vitamin D) trial which aims to establish the best dose of vitamin D to assess in a future large outcome trial.
Methods: The BEST-D trial will compare the biochemical and other effects of daily dietary supplementation with 100 μg or 50 μg vitamin D3 or placebo, when administered for 12 months, in 305 ambulant community-dwelling older people living in Oxfordshire, England. The primary analyses will compare 12-month mean plasma concentrations of 25(OH)D as well as the proportion of participants with a 12-month concentration >90 nmol/L between participants allocated 100 μg and participants allocated 50 μg daily. Secondary analyses will compare the two active doses (both separately and when combined) with placebo. Additional end-points include biochemical assessments of safety, blood pressure, arterial stiffness, falls, fractures, heel and wrist bone density, grip strength and physical performance and echocardiographic assessments of cardiac function in a random sample of participants.
Results: About one-third of eligible participants agreed to participate in the trial. The mean age was 72 (SD 6) years with equal numbers of men and women. About one third reported a prior history of fracture or hypertension, one-fifth reported a prior cardiovascular event, and one tenth reported diabetes or a fall in the previous 6 months.
Conclusions: The results of this trial will help determine the optimum dose of vitamin D to test in a larger trial investigating whether vitamin D supplementation can reduce the risk of fractures, cardiovascular disease or cancer.
(ISRCTN Number 07034656; EudraCT Number 2011-005763-24)