Effect of monthly high‐dose vitamin D on bone density in community‐dwelling older adults substudy of a randomized controlled trial. (26th July 2017)

• Record Type: Journal Article
• Authors: Reid, I. R.; Horne, A. M.; Mihov, B.; Gamble, G. D.; Al‐Abuwsi, F.; Singh, M.; Taylor, L.; Fenwick, S.; Camargo, C. A.; Stewart, A. W.; Scragg, R.
• Is Part Of: Journal of internal medicine. Volume 282:Number 5(2017)
• Page Start: 452
• Page End: 460
• Publication Date: 2017-07-26
• Subjects: clinical trial -- osteoporosis -- vitamin D -- vitamin D deficiency; Internal medicine -- Periodicals; Medicine -- Periodicals; 616
• DOI: 10.1111/joim.12651
• Languages: English
• ISSNs: 0954-6820

Abstract

Abstract: Background: Severe vitamin D deficiency causes osteomalacia, yet trials of vitamin D supplementation in the community have not on average demonstrated benefit to bone mineral density (BMD) or fracture risk in adults. Objective: To determine whether monthly high‐dose vitamin D supplementation influences BMD in the general population and in those with low 25‐hydroxyvitamin D levels. Methods: Two‐year substudy of a trial in older community‐resident adults. A total of 452 participants were randomized to receive monthly doses of vitamin D3 100 000 IU, or placebo. The primary end‐point was change in lumbar spine BMD. Exploratory analyses to identify thresholds of baseline 25‐hydroxyvitamin D for vitamin D effects on BMD were prespecified. Results: Intention‐to‐treat analyses showed no significant treatment effect in the lumbar spine (between‐groups difference 0.0071 g cm −2, 95%CI: −0.0012, 0.0154) or total body but BMD loss at both hip sites was significantly attenuated by ~1/2% over 2 years. There was a significant interaction between baseline 25‐hydroxyvitamin D and treatment effect ( P = 0.04). With baseline 25‐hydroxyvitamin D ≤ 30 nmol L −1 ( n = 46), there were between‐groups BMD changes at the spine and femoral sites of ~2%, significant in the spine and femoral neck, but there was no effect on total body BMD. When baseline 25‐hydroxyvitamin D was >30 nmol L −1, differences were ~1/2% and significant only at the total hip. Conclusions: This substudy finds no clinically important benefit to BMD from untargeted vitamin D supplementation of older, community‐dwelling adults. Exploratory analyses suggest meaningful benefit in those with baseline 25‐hydroxyvitamin D ≤ 30 nmol L −1 . This represents a significant step towards a trial‐based definition of vitamin D deficiency for bone health in older adults. Abstract : Click here to view the Editorial Comment by R. Bouillon.