Influence of cholecalciferol supplementation on changes in total 25OHD, free 25OHD, and free 25OHD % in relation to calcium, bone, and glucose homeostasis in young, infertile men.

What Was Tested

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

While all types of vitamin D metabolites are bound to vitamin D binding protein and albumin leaving only a small fraction in its free active form, only serum concentrations of total 25-hydroxy vitamin D (25OHD) are used to determine vitamin D status in clinical practice.

Who Took Part

The abstract describes 307 men taking part.

By PubMed's age tags, the people studied were young adults and adults, men only.

Secondary data from a single-center, double-blinded, randomized, placebo-controlled clinical trial (NCT01304927) in 307 infertile men.

How the Study Was Run

The design is described as randomized, double-blind and placebo-controlled.

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.

Neither the men nor the staff measuring them knew who was on Vitamin D, K2, Magnesium and Zinc, so expectations could not easily colour the readings.

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

What Was Measured

The subject headings attached to it are Cholecalciferol, Vitamin D, Dietary Supplements, Infertility, Male, Calcium, Homeostasis and Blood Glucose.

The authors tagged it with the keywords 25OHD, Free hormone hypothesis and Free vitamin D.

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 307 men.

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

Results are reported in around 6 sentences of the abstract; we leave them to the paper itself rather than summarise them.

The publication is from 2025 (The Journal of steroid biochemistry and molecular biology), a journal based in England.

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