Randomized controlled trial of the effects of calcium with or without vitamin D on bone structure and bone-related chemistry in elderly women with vitamin D insufficiency

Kun Zhu, David Bruce, Nicole Austin, Amanda Devine, Peter R. Ebeling, Richard L. Prince

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35 Citations (Scopus)

Abstract

There are few data on the relative effects of calcium supplementation with or without extra vitamin D on BMD in patients selected for low vitamin D status. The aim of this study is to evaluate the relative importance of vitamin D and calcium treatment on BMD and bone-related chemistry in elderly women with vitamin D insufficiency. Three hundred two elderly women (age, 77.2 ± 4.6 yr) with serum 25(OH)D concentrations <60 nM participated in a 1-yr randomized, double-blind, placebo-controlled trial. All subjects received 1000 mg calcium citrate per day with either 1000 IU ergocalciferol (vitamin D 2) or identical placebo (control). The effects of time and time treatment interactions were evaluated by repeated-measures ANOVA. At baseline, calcium intake was 1100 mg/d, and 25(OH)D was 44.3 ± 12.9 nM; this increased in the vitamin D group by 34% but not the control group after 1 year (59.8 ± 13.8 versus 45.0 ± 13.3 nM, p < 0.001). Total hip and total body BMD increased significantly, and procollagen type I intact N-terminal propeptide (PINP) decreased during the study with no difference between the treatment groups (hip BMD change: vitamin D, +0.5%; control, +0.2%; total body BMD change: vitamin D, +0.4%; control, +0.4%; PINP change: vitamin D, -3.9%; placebo, -2.8%). Although the fasting plasma and urine calcium increased in both groups equally, there was no detectable change in serum PTH. The increase in 25(OH)D achieved with vitamin D supplementation had no extra effect on active fractional intestinal calcium absorption, which fell equally in both groups (vitamin D, -17.4%; control, -14.8%). In patients with a baseline calcium intake of 1100 mg/d and vitamin D insufficiency, vitamin D2 1000 IU for 1 year has no extra beneficial effect on bone structure, bone formation markers, or intestinal calcium absorption over an additional 1000 mg of calcium. Vitamin D supplementation adds no extra short-term skeletal benefit to calcium citrate supplementation even in women with vitamin D insufficiency.

Original languageEnglish
Pages (from-to)1343-1348
Number of pages6
JournalJournal of Bone and Mineral Research
Volume23
Issue number8
DOIs
Publication statusPublished - 1 Aug 2008
Externally publishedYes

Keywords

  • BMD
  • Calcium
  • Elderly women
  • Intestinal calcium absorption
  • Vitamin D

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