Effect of supplementation with vitamin D on biochemical markers of iron status and erythropoiesis in older people: BEST-D trial.

What Was Tested

This randomized controlled trial looks at Vitamin D, K2, Magnesium and Zinc.

Using placebo-controlled randomisation, the researchers assessed the effects of supplementation with vitamin D on biochemical markers of Fe status and erythropoiesis in community-dwelling older people living in the UK.

The researchers estimated the effect of vitamin D allocation on plasma levels of hepcidin, soluble transferrin receptor (sTfR), ferritin, Fe, transferrin, saturated transferrin (TSAT%) and the sTfR-ferritin index.

Who Took Part

The abstract describes 305 participants taking part.

By PubMed's age tags, the people studied were older adults and people over 80, both men and women.

How the Study Was Run

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

Because people in this Vitamin D, K2, Magnesium and Zinc study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

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

The comparison arm used a placebo, so changes seen with Vitamin D, K2, Magnesium and Zinc could be set against what happens without it.

What Was Measured

Using placebo-controlled randomisation, the researchers assessed the effects of supplementation with vitamin D on biochemical markers of Fe status and erythropoiesis in community-dwelling older people living in the UK.

The researchers estimated the effect of vitamin D allocation on plasma levels of hepcidin, soluble transferrin receptor (sTfR), ferritin, Fe, transferrin, saturated transferrin (TSAT%) and the sTfR-ferritin index.

Topics PubMed links to this paper include Erythropoiesis, Dietary Supplements, Biomarkers, Hepcidins, Iron, Ferritins and Receptors, Transferrin.

The authors tagged it with the keywords Healthy older population, Randomised Controlled Trial and Vitamin D supplementation.

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 305 participants.

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

The publication is from 2025 (The British journal of nutrition), a journal based in England.

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