Randomized controlled trial of vitamin D supplementation in older people to optimize bone health
What this study found
Vitamin D3 supplementation increased circulating 25(OH)D and lowered parathyroid hormone, but it did not improve hip bone mineral density over 12 months and there was no clear dose-related skeletal benefit. Hip BMD change did not differ between 24,000 IU and 12,000 IU (P = 0.39) or 48,000 IU and 12,000 IU (P = 0.08), and femoral neck BMD also showed no significant between-dose differences (P = 0.43 and P = 0.62). Twelve-month 25(OH)D concentrations were 55.9, 64.6, and 79.0 nmol/L in the 12,000, 24,000, and 48,000 IU groups, respectively, with P < 0.01 for the lower dose versus the two…
- Study & population
- Randomized controlled, single-center trial in community-dwelling adults aged 70 years and older from northeast England.
- Intervention
- Oral vitamin D3 once monthly for 12 months at one of three doses: 12,000 IU/mo, 24,000 IU/mo, or 48,000 IU/mo.
- Key limitation
- The trial was relatively short for a bone-health outcome and was conducted in a single regional sample of older adults, limiting generalizability.
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Open PDFOriginal abstract
ABSTRACT Background Vitamin D insufficiency is common in older people and may lead to increased bone resorption, bone loss, and increased falls and fractures. However, clinical trials assessing the effect of vitamin D supplementation on bone mineral density (BMD) have yielded conflicting results. Objectives This study examined the effect of vitamin D supplementation on BMD at the hip, using dual-energy X-ray absorptiometry. Methods A total of 379 adults aged ≥70 y (48% women; mean age: 75 y) from the northeast of England were randomly allocated to 1 of 3 doses of vitamin D3 [12,000 international units (IU), 24,000 IU, or 48,000 IU] given once a month. The primary outcome was change in BMD (ΔBMD) at the hip. Secondary endpoints comprised the dose effects on femoral neck BMD, falls, circulating calciotropic hormones, bone turnover markers, and adverse events. Results The mean ± SD baseline plasma 25-hydroxyvitamin D [25(OH)D] concentration was 40.0 ± 20.1 nmol/L, which increased after 12 mo to a mean 25(OH)D of 55.9, 64.6, or 79.0 nmol/L for participants receiving a monthly dose of 12,000, 24,000, or 48,000 IU, respectively (P < 0.01 for difference). There was no between-group difference in ΔBMD. However, parathyroid hormone concentrations decreased in all 3 groups, with a significantly greater decrease in the 48,000-IU group compared with the 12,000-IU group (P < 0.01). There were no differences in any adverse events between groups, with 3 cases of hypercalcemia, none of nephrolithiasis, and 249 falls observed. Conclusions There was no difference in change in BMD over 12 mo between the 3 doses of vitamin D, suggesting no effect of the intervention or a similar attenuation of the anticipated decrease in BMD over 12 mo. The treatment was safe and effective in increasing plasma 25(OH)D concentrations, with no dose-related adverse events. This trial was registered at the EU Clinical Trials Register (EudraCT 2011-004890-10) and the ISRCTN Registry (ISRCTN35648481).