Treatment of osteoporosis with calcium and vitamin D. Systematic review

BACKGROUND: Systematic review of the efficacy of calcium and vitamin D for the treatment of osteoporosis. MATERIAL AND METHOD: Review of the database MEDLINE between 1996 and may 19 98, by the key words: osteoporosis, calcium, vitamin D (and related terms) and randomized clinical trial. Review of the electronic versions of Best Ev idence, The Cochrane Library, congress abstracts and references from two ma in textbooks. Ascending review of the literature. All the reviews were perf ormed independently by two of the authors. Design parameters and main resul ts of the primary publications of the identified trials were tabulated. Two independent observers carried out methodological scoring of the studies. R esults were tabulated and a judgement made for the results. RESULTS: Eleven studies on calcium, 8 of vitamin D and 12 about calcitriol and other hormone derivatives were included. Studies with calcium were main ly performed on non-clinical populations and in three anti-fracture efficac y was analyzed. Results were positive in population with low baseline intak e and substantial supplementation. Trials on vitamin D were done in non-cli nical and on institutionalized populations. Trials with calcitriol were dev eloped mainly in osteoporotic fracture populations and reached poorer metho dological validity scores. Heterogeneity of the studies precluded a meta-an alysis of the different treatments. Studies on calcium showed clinical effi cacy in a more consistent way. Inter-observer score was good (kappa = 0,81) and there were no significant correlations between sample size and effect in the different studies. CONCLUSIONS: Calcium treatment is efficacious in populations with low intak e receiving substantial supplementation. Vitamin D is efficacious associate d with calcium mainly in deficient populations. Efficacy of calcitriol and other derivatives is more controversial.