Effectiveness and safety of vitamin D in relation to bone health.

What It Covers

The paper reports a study of Vitamin D, K2, Magnesium and Zinc, published as a systematic review.

To review and synthesize the literature in the following areas: the association of specific circulating 25(OH)D concentrations with bone health outcomes in children, women of reproductive age, postmenopausal women and elderly men; the effect of dietary intakes (foods fortified with vitamin D and/or vitamin D supplementation) and sun exposure on serum 25(OH)D; the effect of vitamin D on bone mineral density (BMD) and fracture or fall risk; and the identification of potential harms of vitamin D above current reference intakes.

Why It Was Studied

MEDLINE(R) (1966-June Week 3 2006); Embase (2002-2006 Week 25); CINAHL (1982-June Week 4, 2006); AMED (1985 to June 2006); Biological Abstracts (1990-February 2005); and the Cochrane Central Register of Controlled Trials (2nd Quarter 2006).

Who the Included Studies Covered

PubMed indexes the participants as infants, young children, children, teenagers and older adults, both men and women.

Two independent reviewers completed a multi-level process of screening the literature to identify eligible studies (title and abstract, followed by full text review, and categorization of study design per key question).

Study criteria for question one were broadened to include observational studies due to a paucity of available RCTs, and question four was restricted to systematic reviews to limit scope.

How the Review Was Done

To minimize bias, study design was limited to randomized controlled trials (RCTs) wherever possible.

Data were abstracted in duplicate and study quality assessed.

Differences in opinion were resolved through consensus or adjudication.

If clinically relevant and statistically feasible, meta-analyses of RCTs on vitamin D supplementation and bone health outcomes were conducted, with exploration of heterogeneity.

When meta-analysis was not feasible, a qualitative systematic review of eligible studies was conducted.

What Was Measured

The subject headings attached to it are Bone Density, Bone Density Conservation Agents, Bone and Bones, Dietary Supplements, Fractures, Bone, Lactation and Osteoporosis, Postmenopausal.

What This Means in Plain Language

This is a systematic review of Vitamin D, K2, Magnesium and Zinc.

Its findings take up roughly 40 sentences of the abstract and are left out here on purpose; the source paper is the place to read them.

The publication is from 2007 (Evidence report/technology assessment), a journal based in United States.

More context: the Vitamin D, K2, Magnesium and Zinc compound page, all human trials.