Effects of vitamin D supplementation on symptoms of depression in overweight and obese subjects: randomized double blind trial.

What Was Tested

Researchers studied Vitamin D, K2, Magnesium and Zinc in this randomized controlled trial publication.

The objective of the present study was to examine the cross-sectional relation between serum 25-hydroxyvitamin D [25-(OH) D] levels and depression in overweight and obese subjects and to assess the effect of vitamin D supplementation on depressive symptoms.

Who Took Part

According to the abstract, 441 subjects were involved.

By PubMed's age tags, the people studied were young adults, adults, middle-aged adults and older adults, both men and women.

A total of 441 subjects (body mass index 28-47 kg m(-2), 159 men and 282 women, aged 21-70 years) recruited by advertisements or from the out-patient clinic at the University Hospital of North Norway.

How the Study Was Run

The researchers set it up as a randomized, double-blind and placebo-controlled study.

Random assignment meant chance, not the researchers, decided who got Vitamin D, K2, Magnesium and Zinc and who got the comparison, which limits bias.

Blinding on both sides kept the subjects and researchers unaware of who received Vitamin D, K2, Magnesium and Zinc.

Some subjects received a placebo instead of Vitamin D, K2, Magnesium and Zinc, giving a reference point.

What Was Measured

Topics PubMed links to this paper include Biomarkers, Cross-Sectional Studies, Depression, Obesity, Overweight, Parathyroid Hormone and Psychiatric Status Rating Scales.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Vitamin D, K2, Magnesium and Zinc in 441 subjects.

With several hundred people or more, it is a fairly large study for this kind of research.

The abstract goes on to report its results in about 6 sentences; this page does not restate them, so read the paper for the findings and their limits.

The publication is from 2008 (Journal of internal medicine), a journal based in England.

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