Combined calcium and vitamin D supplementation is not superior to calcium supplementation alone in improving disturbed bone metabolism in patients with congestive heart failure.

What Was Tested

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

To clarify the potential role of vitamin D supplementation on bone metabolism in congestive heart failure (CHF) patients with low vitamin D status and insufficient dietary calcium intake.

Who Took Part

The abstract describes 14 participants taking part.

PubMed indexes the participants as middle-aged adults, men only.

One hundred and two ambulatory male CHF patients were recruited, of whom the majority was treated with loop diuretics.

Additional 14 participants dropped out prematurely because their health status worsened markedly.

How the Study Was Run

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

The participants were allocated by chance, so the Vitamin D, K2, Magnesium and Zinc group and the comparison group should start out alike.

As a double-blind Vitamin D, K2, Magnesium and Zinc study, the assignments were hidden from both participants and investigators until the end.

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

Five patients had to be excluded due to lack of compliance.

What Was Measured

PubMed files the paper under topics including Biomarkers, Bone Resorption, Bone and Bones, Calcium, Calcium, Dietary, Dietary Supplements and Drug Synergism.

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 14 participants.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

Results are reported in around 4 sentences of the abstract; we leave them to the paper itself rather than summarise them.

The publication is from 2008 (European journal of clinical nutrition), a journal based in England.

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