title: Vitamin D supplements with or without calcium to prevent fractures.
abstract: Vitamin D deficiency is associated with fractures. This relationship is biologically plausible. The results of 19 randomized clinical trials with vitamin D with or without calcium show varying results: a decreased fracture incidence in 7, neutral in 10 trials, whereas 2 trials with a high dose of vitamin D once per year showed an increased fracture incidence. In three out of four well-powered trials that used recommended doses of vitamin D 700-1000 IU per day, vitamin D supplementation did not significantly influence fracture risk. In one of these trials, a statistically significant fracture reduction was observed in nursing home residents having severe vitamin D deficiency, low calcium intake and good compliance. Thirteen meta-analyses were done, and 11 of these showed a significantly decreased fracture incidence in the supplemented groups. Vitamin D alone was not effective, studies combining vitamin D and calcium showed inconsistent results. Analyses for vertebral fractures were negative in all cases. In conclusion, a vitamin D supplement of 800 IU per day in combination with calcium may decrease the incidence of non-vertebral fractures, especially in persons in the older age groups having low-baseline vitamin D status and low calcium intake and showing good compliance.
authors.affiliation: Endocrine Section, Department of Internal Medicine, VU University Medical Center , Amsterdam, The Netherlands.
authors.forename: Paul
authors.initials: P
authors.lastname: Lips
authors.affiliation: Geriatric Medicine, Department of Clinical and Experimental Medicine, University Hospitals Leuven , KU Leuven, Leuven, Belgium.
authors.forename: Evelien
authors.initials: E
authors.lastname: Gielen
authors.affiliation: Department of Epidemiology and Biostatistics, EMGO Institute for Health and Care Research, VU University Medical Center , Amsterdam, The Netherlands.
authors.forename: Natasja M
authors.initials: NM
authors.lastname: van Schoor