Why have recent data failed to show the value of vitamin D supplementation? This study offers a clue.
Reference1. Macdonald HM, Reid IR, Gamble GD, et al. 25-Hydroxyvitamin D threshold for the effects of vitamin D supplements on bone density: secondary analysis of a randomized controlled trial. J Bone Miner Res. 2018 Apr 17. doi: 10.1002/jbmr.3442. [Epub ahead of print]
Macdonald and fellow researchers in the UK and New Zealand found that vitamin D supplementation is effective in increasing bone mineral density (BMD) only in those with 25-hydroxyvitamin D (25OHD) levels ≤ 30 nmol/L.1
Scroll through the slides for the details of their study and the take-home points for clinicians.
BMD, bone mineral density; 250HD, 25-hydroxyvitamin D.
BMD, bone mineral density; 250HD, 25-hydroxyvitamin D.
Baseline concentrations of 1,25-dihydroxyvitamin D were comparable in those with 25OHD below or above 30 nmol/L, and there were no changes in this metabolite with treatment, irrespective of baseline 25OHD status.
Using a threshold of 25 nmol/L tended to produce even more marked contrasts: a > 2% treatment effect at the spine (1000 IU/d compared with placebo, P = .002) and ≥ 1% at the hip, in those with 25OHD ≤ 25 nmol/L, compared with no treatment effects in those starting above this level (P = .14 – .44).
